Self-Contained Air Conditioning System - Daikin Applied

Self-Contained Air Conditioning System

Type SWP 018 through 105Capacity: 20 to 125 ton

Catalog 860-7

MEA342-99-E

ContentsIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Agency Listed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

McQuay Self-Contained VAV Systems . . . . . . . . . . . . . . 4Design Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

System Flexibility with Unit Options . . . . . . . . . . . . . . . . 10Selection/Application Flexibility . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Arrangement Flexibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Optimal Discharge Air Temperature . . . . . . . . . . . . . . . . . . . . . . . 10Filtration Flexibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Acoustic Discharge Plenum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Energy Saving Economizer Flexibility . . . . . . . . . . . . . . . . . . . . . . 10Heating Flexibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Summary of Available Options . . . . . . . . . . . . . . . . . . . . . . . . . . . 11McQuay MicroTech II Multiple Air Handler Control (MAC) . . . . . . 11Ultraviolet Lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Refrigerant R-407C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

MicroTech II Unit Controller . . . . . . . . . . . . . . . . . . . . . . . . 13Protocol Selectability Feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Stand-Alone Controller Features . . . . . . . . . . . . . . . . . . . . . . . . . 14Standard Control Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Discharge Temperature Control . . . . . . . . . . . . . . . . . . . . . . . . . . 17Zone Temperature Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Duct Static Pressure Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Operating States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Alarm Management and Control . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Application Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 22General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Unit Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Acoustical Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Equipment Room . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23Ductwork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23Condenser Water Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23Head Pressure Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23Variable Air Volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24Duct Static Pressure Sensor Placement . . . . . . . . . . . . . . . . . . . .24Zone Sensor Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24Filtration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24System Operating Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24Coil Freeze Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25Air Density Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25Unit Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26Terms of Sale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Selection Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27Physical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

R22 Unit Efficiency Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30Correction Multipliers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Performance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32DX Cooling Capacity Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32Waterside Economizer Capacity . . . . . . . . . . . . . . . . . . . . . . . . . .40Heating Capacity Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44Electric Heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44Component Pressure Drops . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45Fan Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49

Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55Recommended Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59Supply Power Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61

Unit Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62Engineering Guide Specifications . . . . . . . . . . . . . . . . . .64

IntroductionContinued Leadership in Self-Contained System DesignsMcQuay SWP Self-Contained air conditioning systems trace their history to the late 1970s and the pioneering concepts of Blazer Industries. Working closely with the consulting engineer to solve special system and space challenges, Blazer Industries developed and provided the first self-contained, variable air volume systems with water side economizer cycle for the prestigious 499 Park Avenue office building in New York City. Following the success of this project was over a decade of innovation and product leadership, with more than thousands of systems provided for prominent building projects.

Agency Listed

Nomenclature

MEA368-93-E

VintageD = Individual refrigerant circuit, 18–95 tonsE = Individual refrigerant circuit, 105 tonsF = Dual refrigerant circuit

Nominal tons

Self-containedWater cooled

Plenum discharge

SWP- 055 - F

McQuay Cat 860-7 3

McQuay Self-Contained VAV SystemsSystem performance provides tenant comfort and operating economy

Since the introduction of self-contained systems in the late 1970s, the industry has seen this concept grow into one of the most widely specified systems for new office buildings, for retrofitting existing structures, and for institutional, industrial, and other specialized applications. The reason is simple: system performance. McQuay SWP Self-Contained VAV systems provide the total performance advantage of the following:• Tenant comfort

– Tenants enjoy individual control over comfort conditions and off-hour system operation.

– Tenants benefit from their individual efforts to control energy costs.

– Routine service is located where it minimizes tenant inconvenience.

– Individual or dual systems per floor provide system redundancy and standby.

• First cost economics

– VAV system flexibility uses building diversity to reduce system tonnage and first cost.

– Factory-packaged concept reduces field labor, installation time and expense.

– No expensive chilled water piping or chiller room.– Individually tested, factory-designed systems reduce

startup and installation expense.– Reduced penthouse and equipment room requirements.– Centralized condenser water and condensate piping and

streamlined system layout.• Energy-saving VAV system control

– Reduces fan kW and operating costs at part load conditions.

– Savings maximized through use of variable speed fan control.

– Individual zone control without overcooling or use of reheat.

• Quiet system operation

– Provided by structural quality and specialized design.– Recognized for quiet operation by renowned U.S.

acoustical consultants.• Energy saving economizer operation

– Water or air economizer capability for optimized energy savings.

– Economizer reduces compressor operating hours and energy costs.

– Year-round “free cooling” capability.

Figure 1: McQuay Self-Contained VAV Systems

• Energy saving building part load operation

– System energy efficiency comparable to central chilled water systems.

– Multiple systems and compressors versus a single, large central plant.

– Efficient and reliable system for partial occupancy and after hours operation.

– Operates only the system(s) on the floor(s) requiring after hours use.

• System savings of advanced MicroTech II® DDC control system

– Monitoring and diagnostics reduce the potential for expensive field repairs.

– Industry leading Protocol Selectability™ feature provides effective BAS selection flexibility.

• Reduced system maintenance and service costs

– No complicated central chiller plant to maintain.– Service and maintenance are performed out of the

occupied space.– Control and product reliability functions designed by the

equipment manufacturer for single source responsibility and improved reliability.

• System versatility

– Applicable to schools, offices, shopping centers, manufacturing facilities, etc.

– Prime candidate for floor by floor building renovation.– Retrofit alternative where existing chiller cannot be

accessed for replacement.

4 McQuay Cat 860-7

McQuay Self-Contained VAV Systems

Design Features

Cabinet, Casing, and Frame

For vibration control and rigging strength, the SWP unit base is constructed of welded, structural steel channel and 10-gauge galvanized steel panels. Heavy-duty lifting brackets are strategically placed for balanced cable or chain hook lifting.

For long equipment life, unit exterior panels are constructed of heavy gauge, pre-painted, galvanized steel. The complete cabinet, frame, and access panels are insulated with 1-inch thick, 1.5 lb. dual density insulation. Double wall construction is available to enhance performance and satisfy IAQ requirements.

For maintenance and service ease, system components are strategically located for ease of inspection and maintenance. Refrigeration components are positioned out of the airstream so adjustments and readings can be made without disrupting system operation. Service-friendly access is made through heavy-duty, convenient, removable panels. Access panels are set on neoprene gaskets to prevent air leakage.

Figure 2: SWP Cabinet

Condensing Section

Compressors

Multiple compressors and refrigerant circuits are featured in all SWP systems for efficient system part load control, quiet operation, and system redundancy. Compressors are quiet, reliable hermetic scroll or reciprocating type complete with sightglass, anti-slug protection, and motor overload protection. The following refrigeration service valves are optional:• Dual refrigeration circuit units are available with liquid and

discharge line service valves to allow the charge to be isolated in the condenser.

• Independent refrigeration circuit units are available with service valves on both sides of each compressor and filter drier. The compressor suction and discharge valves include unions to allow compressors to be replaced without any cutting or brazing.

Individual current-sensing, and temperature-sensing overloads are provided for each compressor. The unit’s MicroTech II control system incorporates timing functions to prevent compressor short cycling. All compressors are resiliently mounted to minimize any noise transmission. The condensing section is insulated and segregated from the air handling section of the unit to avoid transmitting noise to the circulated air stream.

Refrigerant Circuits

Two refrigerant circuit options are available. • Four-compressor units are available with two refrigerant

circuits resulting in good reliability and back up, lowest cost, best part load efficiency, and best value (standard on four-compressor units).

• Each compressor is supplied with its own independent refrigerant circuits providing maximum back up and redundancy (standard on three- and six-compressor units).

Each refrigerant circuit is complete with • Filter-drier• Liquid moisture indicator/sightglass• Thermal expansion valve capable of modulation from 100%

to 25% of its rated capacity gauge ports• Liquid line shutoff valve with charging port• High pressure relief device and high and low pressure

cutouts

Hot gas bypass is available on units with two refrigerant circuits.

The unit’s MicroTech II controller senses entering condenser water temperature and prevents mechanical cooling when the temperature falls below an adjustable set point value, minimum 55°F. For systems with entering condenser water temperatures below 55°F, a waterside economizer or head pressure activated control valve is available.

Condensers

SWP water-cooled condensers feature a mechanically cleanable, all copper design using the same high performance enhanced tubing found in modern centrifugal chillers. Liquid refrigerant subcooling is provided as standard. Each condenser is part of an independent refrigerant circuit and comes complete with a spring-loaded high pressure relief valve. All condensers are independently leak tested. All completed units are leak tested, evacuated, and shipped with a full operating charge of R-22 and oil. R-407C is also available as an alternate selection.

McQuay Cat 860-7 5


The condenser assembly and all factory water piping is rated for a waterside working pressure of 400 psig (200 psig on size 105E with water economizer) and is factory leak tested before shipment. Condenser water channels are mechanically cleanable by removing brass service plugs that are sealed with reusable O-ring gaskets. Main interconnecting condenser water headers include vent and drain plugs and a large cleanout plug for removing debris dislodged during cleaning. Condensers are factory piped for a single condenser water supply and a single condenser water return connection. Both right-hand and left-hand piping locations are available.

Cooling Coil Section

SWP evaporator coils incorporate a high efficiency ripple corrugated fin design. SWP system design maximizes coil face area without developing uneven, performance-robbing disruptions in airflow patterns. The result is high coil performance and reduced static pressure losses.

The evaporator coil is mounted in a stainless steel, double-sloped drain pan. The condensate drain line is trapped internally to the unit, eliminating the expense and inconsistency of field-installed traps.

Figure 3: Evaporator Coil Circuiting

All evaporator coils are interlaced circuiting, keeping the full face of the coil active to eliminate air temperature stratification. For optimum part load performance, all three-circuit and four-circuit evaporator coils are circuited for both interlaced and row control. Compressor staging is sequenced to take maximum advantage of available coil surface.

Each evaporator coil circuit is furnished with a wide range thermostatic expansion valve with an adjustable superheat setting and external equalizer.

Heating Section

SWP units are available as cooling only systems or with factory-installed electric or hot water heat for morning warm-up, constant volume, and specialty heating requirements.

Electric Heat

The factory-assembled electric heating coils are constructed of low-watt density nickel-chromium elements for long lasting durability. Electric heaters are protected by automatic reset high limit controls and line break protection. Heater branch circuits are protected individually by branch circuit fusing. The MicroTech II control system sequences the electric heating elements for operating economy.

Hot Water Heat

Hot water coils have one or two rows with high efficiency ripple corrugated fin design and 1/2 inch O.D. seamless copper tubes. Coils are available complete with a factory-mounted, piped, and wired two-way or modulating valve controlled by the unit’s MicroTech II controller. A factory-mounted freezestat is provided to help protect against coil freeze-up.

Supply Fan Section

Figure 4: Supply Fan

The supply fan section uses a double width, double inlet, medium pressure, forward curved or airfoil fan and housing. Each fan is statically and dynamically balanced. The fan assembly is constructed of high strength structural steel and welded for maximum strength. The entire fan assembly is mounted on spring isolators for excellent isolation effectiveness. Seismic control restrained spring isolators are available. A vibration dampening flex connection is installed at the fan discharge. The entire fan, motor, and drive assembly is dynamically balanced at the factory for quiet operation.

Forward curved supply fans are configured with a gradual expansion, aerodynamic duct within the cabinet. This unique gradual expansion feature contributes to the high performance of the SWP by lowering brake horsepower and sound power levels.

All fans are mounted on solid steel shafts rotating in 200,000 hour, pillow block ball bearings with grease fittings. Multiple belt, fixed pitch sheaves are matched to the specific cfm, static pressure, and horsepower requirements of the system. Drives rated for a minimum of 150% of fan design are available. Drive components and fan bearings are easily accessed for periodic maintenance.

Refrig. Flow Ckt 1Refrig. Flow Ckt 2

Ckt 2

Ckt 1

Ckt 1

Ckt 1

Ckt 1

Ckt 1

Ckt 1

Ckt 1

Ckt 1

Ckt 2

Ckt 2

Ckt 2

Ckt 2

Ckt 2

Ckt 2

Ckt 2

Airflow

6 McQuay Cat 860-7


Fan motors are three phase, NEMA design B, rated at 40°C. Motor availability includes high efficiency, open, drip-proof, and totally enclosed selections; EPACT compliant NEMA T-frame selections; and premium efficiency selections. Motors are 1800 rpm with grease-lubricated ball bearings.

VAV Control

Energy saving, advanced technology, variable frequency drive (VFD) fan speed control is available with the convenience and cost savings of factory mounting and testing. All VFD selections are plenum rated. A manually activated bypass contactor is available to allow system operation even in the event of drive service.

MicroTech II controls provide advanced duct static pressure control. Static pressure can be controlled by either single or two-duct static pressure sensors. All VAV systems include an adjustable, duct high-limit switch to protect duct work from excessive pressure.

Economizer Options

Waterside Economizer

An energy saving, waterside economizer package is available on all units. The complete economizer system is factory mounted including a four-row mechanically cleanable coil, control valves, and factory piping complete with cleanouts. The complete economizer package is rated for up to 400 psig waterside working pressure (200 psig for size 105E), and the entire coil and piping assembly is factory leak tested.

Economizer operation is controlled by the SWP’s MicroTech II controller to maximize free cooling potential. Economizer operation is enabled whenever the available cooling tower water temperature is less than the unit entering air temperature by a field-adjustable value, generally 5°F to 7°F. The economizer control valve modulates in response to the cooling load. Control valve operation can be selected to maintain full flow through the unit at all times or to isolate the unit from the condenser water loop when there is no call for cooling to save energy with a variable pumping system. (Economizer control valves do not eliminate the need to provide unit isolation valves.) To extend free cooling savings, mechanical cooling is enabled during economizer operation. Only when the economizer valve is driven 90% open and the cooling load is not satisfied are compressors staged to maintain cooling set point. Economizer control maintains full, free cooling capability until disabled by the economizer changeover set point. A factory-mounted freezestat is provided to help protect against coil freezeup.

Airside Economizer

An airside economizer control package is available for controlling field-installed mixing dampers capable of 100% outside airflow. Economizer operation is controlled by the SWP’s MicroTech II controller to maximize free cooling potential. Economizer operation is enabled whenever an outside air (or comparative) enthalpy sensor or outside air temperature sensor indicates that outside air is suitable for free cooling. The economizer damper control actuator modulates in response to the cooling load. The outside air damper is positioned to maintain minimum ventilation requirements when the economizer is disabled.

To extend free cooling savings, mechanical cooling is enabled during economizer operation. Only when the economizer damper is driven 90% open and the cooling load is not satisfied, are compressors staged to maintain cooling set point. Economizer control maintains full free cooling capability until disabled by the economizer changeover set point. Factory-supplied mixing boxes are available for airside economizer use using the McQuay Vision™ air handling unit platform.

Condenser Head Pressure Control

For applications where a waterside economizer package is not being used and entering condenser water temperatures can be less than 55°F, condenser head pressure control is required. To satisfy these applications, a factory-installed, two-way, head pressure activated control valve is available to maintain unit operation with entering condenser water temperature as low as 40°F.

Figure 5: Mechanically Cleanable Waterside Economizer Coil

McQuay Cat 860-7 7


Figure 6: Economizer Piping

Filter Section

All SWP units are provided, as standard, with 4" deep, extended media, 30% efficient filters. For higher filtration requirements, 65% and 85% AmericanAirFilterTM Varicel®II filters are available with an optional pre-filter rack. Filters are removable from the rear of the unit or through hinged and latched side access doors on the filter box.

Acoustic Discharge Plenum

To reduce the cost and performance penalties of field-fabricated duct take-offs and transitions, all SWP units offer a factory-mounted, acoustically treated discharge plenum with horizontal duct connections. Custom size duct connections are available on any side of the plenum and are configured at the factory prior to shipment. Field cutting of discharge openings is not required.

The plenum is constructed of prepainted galvanized steel. Plenum walls are insulated with 3 inches of 3 lb. density glass fiber insulation, and the entire interior is lined with a 20-gauge, 23% open, perforated galvanized steel liner for added rigidity and acoustic performance. To reduce turbulence in the plenum and improve performance, the plenum has acoustic baffles installed at the plenum corners. Plenums with a single side discharge opening or a single side with either a front or back opening have an acoustic baffle isolating the unused portion of the plenum.

Electrical

Each unit is completely wired and tested at the factory prior to shipment. Wiring complies with NEC requirements and conforms to all applicable UL standards for reliability and safety. All electrical components are labeled according to the electrical diagram and are UL recognized, whenever applicable. Line voltage components and wiring are physically separated from the low voltage control system.

The supply fan motor, compressor motors, and electric heat all have individual branch circuit, short circuit protection. Control circuit power is supplied through a factory-installed, low voltage transformer. The supply fan motor circuit includes a three-phase contactor and ambient compensated overload protection with manual reset. Each refrigerant circuit includes both a high and low pressure cutout switch and a coil frost protection thermostat.

A terminal block is provided for the single, main power connection, and a terminal board is provided for low voltage control wiring. A factory-mounted, non-fused main circuit interrupter is available for disconnecting the main electrical power to the unit. The switch is visible, located at the front of the unit, and is accessible without unit penetration. Dual power blocks or disconnect switches are available to accommodate requirements for standby, emergency power supplies.

Controls

MicroTech II Unit Controls

All SWP units feature advanced MicroTech II DDC controls to provide all temperature and static pressure control, product reliability, control functions, system time clock, and all monitoring and diagnostics. Each MicroTech II control system features a human interface with a 4-line, 20 character display on the front of the unit for fast system diagnostics and adjustments. Its easy-to-follow and easy-to-read menus and data displays encourage and invite the operator to take advantage of its many capabilities. The complete control system is factory installed and commissioned prior to shipment.

Protocol Selectability™ Feature

All MicroTech II control systems have McQuay’s exclusive Protocol Selectability feature. MicroTech II control systems can be factory configured for standalone operation or incorporated into an independent building automation system using either the BACnet® MS/TP, BACnet®/IP or LonTalk® protocols. All LonTalk communication is LONMARK 3.3 certified.

Figure 7: Keypad/Display Panel

8 McQuay Cat 860-7


Auxiliary Control OptionsCondenser Water Flow Switch. A factory-installed water flow sensor is available to verify water flow status at each unit. Compressor operation is disabled and an alarm signal provided if condenser water flow is lost. Unit operation is restored when water flow is sensed again. Water flow status is displayed on the MicroTech II controls screen.Freezestat. A nonaveraging freezestat is available factory installed on the entering face of the economizer coil. Upon sensing a potential freeze condition, the unit supply air fan shuts down, the economizer (and heating) valve drives to the full open position, and an alarm signal is provided. Unit operation is restored following manual reset of the freezestat.Phase Failure/Undervoltage Protection. Factory-installed phase failure/under voltage protection is available to protect three-phase motors from damage due to single phasing, phase reversal, and low voltage conditions.

Individual Unit Factory Test

All SWP units are completely assembled, piped, wired, and tested at the factory and shipped in one piece. Each unit undergoes a factory test that includes:• Dynamic trim balance of the completed fan assembly• Run check of all electrical components, alarms, and

shutdowns, including proper control sequencing• Pressure tests, at rated pressure, of refrigerant coils, water

coils, and condensers prior to assembly• Final leak checks of the completed refrigerant circuits• Final leak check of the completed water circuit• Compressor run check

Verification of factory run test is available at time of unit shipment.

Figure 8: Test Stand

McQuay Cat 860-7 9

System Flexibility with Unit OptionsAlong with providing high quality and state-of-the-art innovation, SWP self-contained systems offer customized flexibility to satisfy a wide range of diverse applications.

Selection/Application FlexibilityNominal cooling capacities range from 20 to 125 tons. In addition, all units offer multiple compressor selections to meet exacting system requirements. Over 130 different standard compressor/coil capacity selections are available. The flexibility to optimize the self-contained system to fit the application is a McQuay SWP advantage. Available system applications include the following:• VAV discharge air temperature control with static pressure

control• Discharge air temperature control with constant air volume• Constant volume, zone temperature control• 100% outside air control• Dehumidification control, with or without reheat control

In addition to compressor/coil flexibility, SWP systems offer double width, double inlet, forward curved fans with factory-mounted variable frequency drives for maximizing VAV system fan performance. High efficiency fan capability coupled with extensive compressor flexibility provide the right system selection for the application.

Arrangement FlexibilityAll SWP systems offer the flexibility of right-hand and left-hand piping arrangements and front and rear fan discharge orientations. Piping and fan arrangement flexibility can simplify mechanical equipment room arrangement, improve installation costs, and improve total system performance.

Optimal Discharge Air TemperatureMore and more system engineers are designing optimal discharge air temperature systems to improve system performance and system first cost; the McQuay SWP provides the flexibility to do it successfully. Optimal discharge air temperature systems are designed to provide unit leaving air temperature selections of 52°F to 53°F versus more conventional systems that supply air at temperatures closer to 58°F. This five to six degree reduction in air temperature to the room diffusers can subsequently reduce the required supply air volume to the room by 20% to 25%.

The benefits of optimal discharge air temperature systems become quite apparent with a look at the advantages offered with reduced supply air cfm airflow:• Reduced first cost and installation cost by allowing smaller

duct sizes and a smaller air distribution system.

• Reduced bhp requirements. Depending on changes in duct size and the resulting total static pressure, a 20% reduction in supply air cfm can reduce fan bhp requirements by 25% or more.

• Reduced fan sound power generation and a quieter room environment.

• Reduced equipment room size may be possible due to using a physically smaller unit size.

Filtration FlexibilitySWP systems are offered with 4-inch, 30% efficient, pleated filters as standard. Also available are 4-inch, 65% efficient, pleated filters and 4-inch, 85% efficient filters with prefilters.

Acoustic Discharge PlenumWhile others may provide a simple multidirectional discharge plenum, SWP systems feature a multidirectional plenum with true acoustic design qualities.

The following SWT plenum features provide not only application flexibility but also the acoustic performance not found in simple, single-wall plenums:• Heavy-gauge galvanized steel construction• 3-inch, 3-lb., glass fiber thermal/acoustic insulation• An inner, perforated galvanized steel acoustic liner• Internal acoustic baffles

Energy Saving Economizer FlexibilityTo improve system operating performance, all SWP systems offer complete factory-mounted and factory-controlled waterside economizer capability. Each waterside economizer system includes a 4-row, mechanically cleanable coil with dual, 2-way control valves to allow use in either a constant or variable volume pumping system. In addition, units can be applied with air economizer cycles with integrated factory control.

Heating FlexibilityA variety of heating media is offered with each SWP system. Hot water coils with modulating valve and actuator are available along with staged electric heat to provide heating control in a variety of applications.

ControllersMicroTech II DDC control systems provide constant volume, variable air volume, 100% outside air, and/or dehumidification control flexibility. See “Controls” on page 8 for more information.

10 McQuay Cat 860-7

System Flexibility with Unit Options

Summary of Available Options• Over 130 different compressor/coil capacity selections• Multiple control options: VAV, CV, 100% OA,

dehumidification• Nonfused main power disconnect switch• Dual nonfused main disconnect switches• Nonaveraging freezestat for hot water or waterside

economizer coil protection• Unit phase failure/under voltage protection• Premium efficiency fan motors• TEFC fan motors• Condenser water flow switch• 4-row waterside economizer system• Air cycle economizer system• Modulating hot water heat• Staged electric heat• Multi direction, acoustic discharge plenum• Factory-mounted and factory-controlled variable frequency

drives• High efficiency filtration options• Right-hand and left-hand piping selections• Front and back fan discharge arrangements• Head pressure control valve• Special coil coatings• Double wall cabinet construction• Seismic fan isolation• UV lights• Two refrigerant circuit options

– Dual refrigerant circuit units offer the following options:• Three-row or five-row DX coils with enhanced heat

transfer surfaces• Hot gas bypass on one refrigerant circuit• Discharge and liquid line shut off valves for each

circuit– Independent refrigerant circuit units offer the following

options:• Four-row or six-row DX coils with standard heat

transfer surfaces• R-407C or R-22• Shut off valves on each side of each filter drier/sight

glass assembly• Roto-lock suction and discharge service and shut off

valves on each compressor

McQuay MicroTech II Multiple Air Handler Control (MAC)The MicroTech II Multiple Air Handler Control (MAC) provides control coordination for multiple units serving a common space or feeding a common ductwork system.

The MAC manages each group of units to operate in concert. Individual unit controls cannot reliably handle parallel units because the controls fight each other at part load. Inevitably, one unit overpowers the other.

Benefits of Parallel Units on a Common Duct• Improved system reliability as units and sensors can provide

redundancy if a sensor on a unit requires maintenance.• Lower first cost from increased diversity resulting in lower

installed tonnage.• Lower installed cost due to fewer roof penetrations and less

floor-to-floor ductwork.• Improved space temperature control from smaller cooling

stages relative to load and reduced compressor cycling.

Ultraviolet LightsFactory-installed ultraviolet lights are available on the downstream side of all cooling coils and above the unit drain pan.

All ultraviolet lights are pre-engineered and factory installed for ease of use and proper placement for maximum effectiveness. The ultraviolet lamps irradiate the coil and drain pan surfaces with light in the 245 nanometer wavelength of the light spectrum (UV-C). UV-C light has proven effective in killing most bacteria, molds, and viruses in both laboratory and practical application. This complete package of equipment and ultraviolet lights includes Intertek Services Inc. (ETL) safety agency certification.

Features

• High-output, hot cathode lamps produce ultraviolet germicidal irradiation (UVGI) for 254 nm that constantly irradiates the coil and drain pan surfaces.

• Fixture design and stainless steel construction make the ultraviolet light device suitable for saturated air conditions.

• Automatic disconnects are standard on all doors (or panels) with line-of-sight access to the lamps to help prevent eye contact with the UV-C ultraviolet light.

• Special ultraviolet filtering glass windows block ultraviolet light, allowing the coil, drain pan, and lights to be inspected while in use from outside the unit.

McQuay Cat 860-7 11

System Flexibility with Unit Options

Benefits

• For pennies a day, UVGI can improve IAQ by destroying mold, fungi, and bacteria on coil and drain pan surfaces.

• Clean coil surfaces maintain peak heat transfer for “near new” performance and lower energy costs.

• Reduced coil and drain pan maintenance requirements and costs.

• Satisfies GSA federal facilities standard requirements for UVGI lights to be incorporated downstream of all cooling coils and above all drain pans to control airborne and surface microbial growth and transfer.

Figure 9: Ultraviolet Light

Refrigerant R-407C McQuay SWP units with independent refrigerant circuits are available with non-ozone depleting R-407C refrigerant. R-407C refrigerant is better for the environment than R-22 (see the note below).Note – In response to the Montreal Protocol, the United States

EPA announced that R-22 production/imports will be limited starting January 1, 2010, likely ending R-22 use in all new equipment. After January 1, 2020, domestic R-22 production/imports will cease and all service work will require recycled R-22 refrigerant or a replacement such as R-407C.Given the many inherent differences in oil, operating pressure, and control settings between R-22 and the HFC alternatives, future conversion of an R-22 system to an HFC is likely to be difficult and costly.

Features

• HFC-407C refrigerant is environmentally friendly with zero ozone depleting allowance (ODP).

• ASHRAE Standard 34, Designation and Safety Classification of Refrigerants, classifies HFC-407C as an A1 (lower toxicity—no flame propagation) refrigerant.

• Units are factory engineered for proper cooling performance using R-407C.

• Units are factory charged with R-407C and synthetic oil (such as POE), and they include components and controls specifically tailored to R-407C.

• Units are factory tested prior to shipment

Benefits

• HFC-407C allows you to provide your tenants with a comfortable building environment in an environmentally friendly way.

• With no phase out date for production of HFC-407C, a reliable supply should be available for the life of your equipment.

• Fully engineered and factory tested units with R-407C avoid the downtime, high costs, and risk associated with a field conversion of an R-22 system to an R-407C.

12 McQuay Cat 860-7

MicroTech II Unit ControllerDesigned with the system operator in mind, McQuay SWP systems continue to provide industry leading performance, featuring the microprocessor-based MicroTech II Self-Contained System Unit Control system. In addition to providing stable, efficient temperature, and static pressure control, the controller is capable of providing comprehensive diagnostics, alarm monitoring, and alarm specific component shutdown if critical equipment conditions occur.

A user interface featuring an 8-key keypad and a 4-line × 20-character display comes as standard with each MicroTech II control system, providing system operators with superior access to temperatures, pressures, operating states, alarm messages, set points, control parameters, and schedules. All messages are displayed in easy-to-follow text. Password protection is included to protect against unauthorized or accidental set point or parameter changes.

Protocol Selectability FeatureMicroTech II unit control systems are factory configured for either standalone operation or for incorporation into independent building automation systems (BAS) through our Protocol Selectability feature. By using industry recognized communication protocols, BACnet MS/TP®, BACnet®/IP or LonTalk®, McQuay MicroTech II controls expand the horizon of opportunities for BAS choice without sacrificing system performance.

BACnet communications conform to the BACnet Standard, ANSI/ASHRAE Standard 135-2001 and are supported by a protocol implementation conformance statement (PICS).

LonTalk communications are in accordance with either the Discharge Air Controller (DAC) or Space Comfort Controller (SCC) profiles and are LONMARK 3.3 certified.

The building automation system can interact with one or multiple self-contained unit controllers in the following ways: • Set the unit’s operating and occupancy modes • Monitor all controller inputs, outputs, set points, parameters,

and alarms • Set controller set points and parameters • Clear alarms • Reset the cooling and heating discharge air temperature set

point (DAC units) • Reset the duct static pressure set point (DAC units) • Set the heat/cool changeover temperature • Set the representative zone temperature (SCC units)

ComponentsEach SWP self-contained system is equipped with a complete MicroTech II unit control system that is pre-engineered, preprogrammed, and factory tested prior to shipment. Each of the MicroTech II unit control systems is composed of several components that are individually replaceable for ease of service. These components include: • Keypad/display user interface• Main control board • Cooling control board(s)• Communication protocol module (optional) • Pressure transducers • Unit-mounted temperature sensors • Zone temperature sensor packages• Humidity sensor

Main Control Board (MCB)

The main control board (MCB) contains a microprocessor that is preprogrammed with the software necessary to control the unit. This provides that schedules, set points and parameters are not lost, even during a long-term power outage. The microprocessor board processes system input data and then determines and controls output responses. An RS-232 communication port is provided as standard to allow for direct or modem access with a PC-based service tool.

Cooling Control Boards (CCB)

A cooling control board (CCB) is used to expand the input and output capability of the main control board (MCB). Each CCB communicates with the MCB via serial data communications. These microprocessor based boards provide independent operation and alarm response even if communication is lost with the MCB.

Communication Protocol Module (CPM)

The communication protocol module (CPM) provides the means to factory or field configure MicroTech II unit controls for interoperability with an independent BAS using McQuay’s innovative Protocol Selectability feature. Communication protocol modules are available to support industry recognized communication protocols including BACnet MS/TP, BACnetIP, and LonTalk.

McQuay Cat 860-7 13

MicroTech II Unit Controller

Keypad/Display

All MicroTech II controllers include a keypad/display that provides user interface with the main control board (MCB). The keypad/display has eight, easy-to-use, touch-sensitive membrane key switches that are used for positioning the display and entering changes. The display is a supertwist nematic type with highly visible black characters on a yellow background. The 4-line × 20-character format allows for easy-to-understand display messages. All operating conditions, system alarms, control parameters, and schedules can be monitored from the keypad/display. If the correct password is entered, any adjustable parameter or schedule can be modified from the keypad.

Figure 10: MicroTech II Keypad/Display

Temperature and Humidity Sensors

With the exception of the return air sensor and zone sensor, all temperature sensors are factory installed and tested. Return air sensors are factory tested but require field installation in the return air duct. Zone sensor packages are available to suit any application. When required for dehumidification applications, a humidity sensor is available for field installation.

Static Pressure Transducers

All pressure transducers are factory installed and tested. Connection and routing of sampling tubes is done at time of unit installation.

Zone Temperature Sensors

Two types of optional zone temperature sensors are available for use with the MicroTech II controller: • Zone sensor with tenant override switch. • Zone sensor with tenant override switch and remote set point

adjustment.

Timed tenant override is a standard MicroTech II control feature.

Zone sensors are required to utilize the controller’s purge cycle, space reset of supply air set point, and night setback, or setup features (see following). All zone sensors are field installed with field wiring terminated at a separate, clearly marked terminal strip.

Stand-Alone Controller Features MicroTech II self-contained system unit controls include all of the essential features required to make them capable of completely independent, stand-alone operation.

Internal Time Clock

An internal, battery-backed time clock is included with each MicroTech II unit controller. Current date and time can be set quickly and easily at the user interface keypad.

Internal Schedule

Seven daily schedules and one holiday schedule can be entered at the keypad of all unit controllers. For each of these eight schedules, one start and one stop time can be entered. Up to 16 holiday periods of any duration can be designated. The unit automatically runs according to the holiday schedule on holiday dates. To handle special occasions, use an additional “one event” schedule.

In lieu of its internal schedule, the unit can be operated according to a network schedule from the BAS.

External Time Clock or Tenant Override Input

An input is supplied that can be used to accept a field-wired start/stop signal from a remote source. An external time clock, a tenant override switch, or both, can be connected. Whenever the external circuit is closed, the controller overrides the internal schedule (if activated) and places the unit into the occupied mode.

If the internal schedule or a BAS network schedule is used, field wiring is not required.

Timed Tenant Override

Off-hour operation flexibility is a must in today’s office environments; standalone MicroTech II controllers handle it with ease. When unit operation is desired during unoccupied hours, initiate timed tenant override by pressing the tenant override button on either of the optional zone sensor packages. The unit then starts and runs in the occupied mode for a keypad adjustable length of time (up to five hours). If the button is pressed again while the unit is operating, the timer resets to the full time allowance without interrupting unit operation. Tenant override operation also can be initiated by the BAS.

Remote Set Point Adjustment

All constant air volume-zone temperature control (SCC) unit controllers include an input that can be used to remotely adjust the zone cooling and heating set points. To use this feature, wire the optional zone sensor package with set point adjustment to the controller. The remote set point adjustment feature can be enabled or disabled from the keypad at any time. When enabled, the remote set point adjustment is available even if the return temperature is selected to be the Control Temperature.

14 McQuay Cat 860-7


Auto/Manual Operation Selection

Automatic or manual operation can be controlled either remotely or at the keypad.

All controllers include two inputs that can be used to enable or disable cooling, heating, and fan operation from remote switches. With the “heat enable” and “cool enable” terminals, the operator can enable cooling, heating, or both. Using the system “off” terminals, the operator can disable the fans, and thus the entire unit, so that the unit cannot be started remotely.

From the keypad, a variety of occupancy and auto/manual control mode selections are available to the operator:• Occupancy modes

– Auto– Occupied– Unoccupied– Tenant override

• Control modes– Off– Auto– Heat/cool– Cool only– Heat only– Fan only

Compressor Lead-lag Selection

All unit controllers are capable of automatic compressor, lead-lag control. If automatic control is not desired, the operator can disable the compressor lead-lag function.

Waterside Economizer Changeover

On units equipped with a waterside economizer package, the MicroTech II unit controller includes an internal changeover strategy that compares entering cooling tower water temperature to the unit’s mixed air temperature. If the entering water temperature is less than the mixed air temperature by a field-adjustable differential (typically 5°F to 7ºF), the economizer control valve modulates in response to the cooling load.

Airside Economizer Changeover

On units equipped with airside economizer control (control only, economizer mixing dampers by others), there are two methods of determining whether the outdoor air is suitable for free cooling: one method senses enthalpy (dry bulb temperature and humidity) and one senses outdoor air dry bulb temperature.

The enthalpy changeover method uses an external control signal wired to a designated controller input.

All unit controllers include an internal changeover strategy that can be selected at the keypad. When this method is selected, the controller compares the outdoor air dry-bulb temperature, provided by the optional outdoor air temperature sensor, to a keypad programmable set point. The external enthalpy control input then is ignored.

Cooling and Heating Lockout Control

All unit controllers include a keypad programmable set point for locking out mechanical cooling when the entering tower water temperature is below the lockout set point. The factory default set point is 55ºF. The default is adjustable to a minimum of 50ºF when a waterside economizer package is used. For systems without a waterside economizer, an optional head pressure regulating valve is required for operation below 55ºF.

When an economizer system is used, mechanical cooling is locked out whenever the economizer is enabled and the economizer position is less than 90%. This energy saving feature requires that full economizer potential be used before mechanical cooling is allowed to energize.

Night Setback and Setup Control

When one of the available zone temperature sensors is connected to the unit controller, night setback heating and night setup cooling control are available. Separate, keypad programmable, night heating and cooling set points are used to start the unit when necessary. After the unit starts, night setback and setup control is similar to normal occupied control except that the minimum outside air damper position is set to zero. If the outside air is suitable for free cooling, and an airside economizer is used, outside air is used during night setup operation.

Except for 100% outside air applications, night setback control is available even if the unit is not equipped with any heating equipment. When the space temperature falls to the night setback set point, the fan starts and runs until the temperature rises above the differential. This feature may be useful for applications that use duct-mounted heating coils.

Morning Warm-up Control

If the space temperature is below set point when the unit enters the occupied mode, the morning warm-up control function keeps the outside air dampers closed while heat is supplied to satisfy set point. The outside air damper remains closed until either the space temperature rises to the heating set point or the keypad adjustable morning warm-up timer expires (default is 90 minutes). The morning warm-up timer provides that the minimum required amount of outdoor air is supplied after a certain time, regardless of the space temperature.

Morning warm-up control is automatically included on all units except 100% outside air units. It is available even if the unit is not equipped with any heating equipment for applications that use duct mounted heating coils.

McQuay Cat 860-7 15


Condenser Head Pressure Control (units without waterside economizer only)

Mechanical cooling is allowed whenever the entering cooling tower water temperature is 55ºF or warmer, without the use of head pressure control. When the entering water temperature is below 55ºF, a factory-installed and factory-controlled two-way modulating head pressure control valve can be utilized. The regulating valve is controlled by the MicroTech II controller to maintain refrigerant head pressure.

Outdoor Air Purge Control (units with airside economizer only)

Purge control is designed to take advantage of cool early morning outside air conditions. It starts the fans and modulates the economizer dampers to maintain occupied cooling requirements during unoccupied periods, if conditions are appropriate. This provides the opportunity to flush the space with fresh outdoor air prior to occupancy. Purge operation is possible only during a keypad-adjustable time window prior to occupancy (0 to 240 minutes). When the purge-cycle is active, mechanical cooling is disabled. To use the purge feature, connect one of the zone temperature sensors to the unit controller. Below is a description of purge control operation.

During the purge time window, the unit starts and runs whenever these three requirements are met: • The space temperature must be warm enough to enable

occupied cooling.• The outside air enthalpy must be low enough to enable the

economizer. • The outside air temperature must be at least 3°F less than the

space temperature.

When any one of these conditions is no longer true, the unit shuts down. As conditions allow, purge cycles the unit in this manner until it enters the occupied mode.

Proportional Integral Derivative (PID) Control Algorithm

The proportional integral derivative (PID) control algorithm controls modulating actuators to maintain a measured variable (temperature or pressure) at or near its set point. For example, it controls economizer actuators to maintain the discharge cooling set point, and it controls the supply fan variable frequency drives to maintain the duct static pressure set point. The integral control feature effectively eliminates “proportional droop” (load dependent offset) resulting in the tightest possible control.

For each PID loop, five keypad-adjustable parameters allow the control loop to be properly tuned for any application: • Period• Dead band• Proportional band• Integral time

• Derivative time

Appropriate default values for these parameters are loaded into each controller. These default values provide proper control for most applications; therefore, field tuning usually is not required and start-up time is reduced.Change Algorithm. The PID function is also used to adjust set points instead of controlling variable speed drives or actuators directly. For example, in zone control applications, the PID loop automatically “changes” the discharge temperature set point (cooling or heating) as the Control Temperature deviates from the zone set point. Another PID loop then controls the economizer actuator or heating valve actuator using the current discharge temperature set point. Unlike a typical “master-submaster” reset strategy, this “cascade control” continuously adjusts the discharge set point, even if the Control Temperature’s deviation from set point remains constant. This means that the unit’s cooling or heating output is set according to the actual load, not just the current zone temperature. The tightest possible zone temperature control results because “proportional droop” (load dependent offset) is eliminated.

Calibrate

When initiated at the keypad by an operator, the Calibrate function automatically calibrates all actuator position feedback inputs and all pressure transducer inputs. It does this by shutting the unit down and then driving all actuators to the full closed and full open positions. The controller records the input voltage values that correspond to these positions. The pressure transducer input voltages, which are assumed for 0.00" wc, also are recorded. When Calibrate finishes, enter an operator command at the keypad to start the unit. The Calibrate feature can reduce start-up time and assist in periodic maintenance.

Field Output Signals

All MicroTech II controllers include four solid-state relay outputs that are available for field connection to any suitable device: remote alarm output, fan operation output, outside air damper output, and pump start output. On VAV units, an additional VAV box output is also available. These five outputs are used to signal field equipment of unit status. Remote alarm output: Use to operate a 24-volt relay to provide a remote alarm signal to a light, audible alarm, or other device when an alarm condition exists at the unit. Fan operation output: Use to control field equipment that depends on fan operation, for instance, to open field-installed isolation dampers or VAV boxes. To allow actuators enough time to stroke, the fan operation output energizes three minutes before the fans start. It remains energized until thirty seconds after the unit airflow switch senses no airflow. The fan operation output is on whenever the unit airflow switch senses airflow. Outside Air Damper output: Use to signal an outside air damper actuator to open whenever the unit is in an occupied cooling or heating condition.

16 McQuay Cat 860-7


VAV box output: Provides a means of interfacing the unit and the VAV box control. When the output is energized (closed), the VAV output indicates that the unit is in the cooling mode. When de-energized (open), it indicates that the unit is either providing heat or circulating air to equalize temperature conditions just after start-up (this is the Recirculate operating state). On units with single stage “morning warm-up” heat, the open VAV box output contact is meant to provide a signal to drive the boxes wide open. To prevent duct over-pressurization, fan variable speed drives or inlet vanes are driven to a minimum position before the output’s contacts de-energize again for normal cooling operation (Post Heat operating state).Pump Start output: Use to provide a start/stop signal to the cooling tower circulating pump. The pump start output is on whenever fan operation and cooling is required.

Standard Control Options SWP Self-Contained systems are available for most any constant or variable air volume application. MicroTech II controls offer three basic control configurations that use sophisticated state change control logic to provide stable, reliable and efficient control: • Variable air volume with discharge temperature control (DAC)• Constant air volume with zone temperature control (SCC)• Constant air volume with discharge temperature control (DAC)

When combined with MicroTech II’s many available control capabilities, both factory-installed and keypad-programmable, these three basic configurations can be customized to meet the requirements of the most demanding applications.

Variable Air Volume with Discharge Temperature Control (DAC)

All VAV units provide true discharge temperature control in addition to duct static pressure control. Cooling only, cooling with single-stage “morning warm-up” heat, and cooling with modulating heat configurations are available.

Constant Air Volume with Zone Temperature Control (SCC)

SCC units are available in either cooling only or cooling with modulating heat configurations. Either of these configurations is available for 100% recirculated, mixed, or 100% outdoor air applications.

Constant Air Volume with Discharge Temperature Control (DAC)

DAC units are available in cooling only, cooling with single-stage “morning warm-up” heat, or cooling with modulating heat configurations. This unit configuration can be used for applications that have zone controlled terminal heating coils or for constant volume, 100% outdoor air applications. The discharge temperature control strategies used with the hybrid DAC unit are identical to those used with the DAC unit.

Discharge Temperature Control MicroTech II DAC controllers provide sophisticated and flexible discharge air temperature control that is only possible with DDC systems. Separate discharge air temperature set points are used for cooling and modulating heating control. At the keypad, the operator can enter either the desired set points or select separate reset methods and parameters for each set point. See “Supply Air Reset” on page 18.

Control Temperature

The Control Temperature makes the heat/cool changeover decision. It determines whether cooling or heating is enabled. The discharge temperature then determines whether cooling or heating is actually supplied. At the keypad, the operator can choose the source of the Control Temperature from among the following: • Space temperature sensor • Return temperature sensor • Outside air temperature sensor (modulating heat only) • Network communication

The operator enters separate cool and heat enable set points and deadbands to which the Control Temperature is compared (see Figure 11). When the Control Temperature is greater than or equal to the cooling set point, cooling is enabled. When the Control Temperature is less than or equal to the heat set point, heating is enabled. If desired, these set points and differentials can be set so there is a dead band in which both cooling and heating are disabled. The controller’s software prevents simultaneous cooling and heating.

Figure 11: Control Temperature—Discharge Temperature Control

Proportional Integral Derivative Modulation

When operating in economizer free cooling or unit heating, the previously described PID algorithm maintains discharge temperature control. The PID algorithm provides precise control of the economizer dampers, modulating gas heat, steam or hot water valves.

McQuay Cat 860-7 17


Compressor Staging

Two staging algorithms are available to control a unit’s multiple steps of capacity control: “Average” and “Nearest.” These control algorithms provide reliable discharge temperature control while managing compressor cycling rates. Constraints on compressor staging are essential for preventing short cycling, which can reduce compressor life by causing improper oil return and excessive heat buildup in the motor windings.

The “Average” compressor staging algorithm keeps track of the discharge temperature and stages cooling up or down to maintain an average temperature that is equal to the effective discharge cooling set point. A stage change can occur only • After the keypad adjustable inter-stage timer expires (five

minute default setting) • If the discharge temperature is outside a keypad programmed

dead band (see Figure 12).

After these two conditions are met, staging occurs as the controller attempts to equalize two running totals: degree-time above set point and degree-time below set point. The result is that the average discharge temperature is maintained at the cooling set point.

The “Nearest” compressor staging algorithm keeps track of the discharge temperature and stages cooling up or down to maintain it as closely as possible to the set point. A stage change can occur only• After the keypad adjustable inter-stage timer expires (five

minute default setting)• If the control logic calculates that a stage change will result

in a discharge temperature closer to set point than the existing condition.

The controller logic continually calculates the expected effect of a stage change and uses this information before making a change. A change is made only if it brings the discharge temperature closer to set point, resulting in a more consistent discharge temperature, reduced compressor cycling, and more stable VAV box control.

Figure 12: Compressorized Discharge Air Cooling

Supply Air Reset

Supply air reset can increase the energy efficiency of VAV systems by automatically varying the discharge air temperature to suit a building’s cooling or heating needs. MicroTech II controllers offer a variety of different reset strategies that can be selected at the keypad. Because they are keypad programmable, reset strategies can be changed or eliminated as desired. Separate strategies can be selected for cooling and for modulating heat. If reset is not desired, a fixed discharge cooling or heating set point can be entered.

The following reset methods are available: • Space temperature • Return temperature • Outdoor air temperature • Supply airflow (VAV, cooling set point only) • External 1–5 VDC or 4–20 mA signal• Network communication

For all temperature reset methods, the minimum and maximum cooling and heating set points are keypad programmable along with the corresponding minimum and maximum space, return or outdoor air temperature parameters. For the supply airflow method, the discharge set point is reset as the supply fan modulates between 30% and 100%. For the external method, the discharge set point is reset as the voltage or current signal varies over its entire range. For units in a BAS network, the discharge set points are reset via the communication signal.

Zone Temperature Control The MicroTech II SCC control system provides the sophisticated and flexible zone temperature control that is only possible with DDC systems. Zone temperature sensors are available with or without a remote set point adjustment. With the remote adjustment model, the space set point can be set at the keypad or at the zone sensor package. (Even if a zone sensor is connected, remote set point adjustment can be enabled or disabled as desired at the keypad.)

Control Temperature

Control Temperature is the representative zone temperature. When compared with the zone set points, it determines whether the unit supplies heating or cooling, or neither. It also determines the amount of cooling or heating required to satisfy the load. Its source, selected at the keypad, is either the zone temperature sensor or the return temperature sensor

The Control Temperature is the primary input to the MicroTech II zone temperature control algorithms. Figure 11 on page 17 shows the parameters with which the Control Temperature is compared to control the cooling or heating output. The functions of these parameters are described below. The controller’s software prevents cooling and heating from being enabled at the same time.

18 McQuay Cat 860-7


Change and Proportional Integral Derivative Modulation

When economizer “free” cooling or unit heating is required, the two MicroTech II PID loops combine to provide cascade control, the tightest possible zone temperature control. By controlling the discharge temperature and the zone temperature, these functions eliminate temperature variations near the diffusers, which can occur with traditional zone control due to its inherent lag effect.Change: If the Control Temperature is above or below the set point by more than the dead band, the Change PID loop adjusts the cooling or heating discharge air temperature set point as necessary. The amount of this set point change corresponds to the Control Temperature’s position in the modulation range. The farther the Control Temperature is from the set point, the greater the change. Set point changes are limited to ranges defined by keypad-programmable maximum and minimum values. PID: The PID function uses the Change function’s current discharge set point to maintain precise discharge temperature control by modulating the economizer dampers and gas heat, steam or hot water heating valves.

Compressor Staging

Compressor staging is controlled directly by the Control Temperature. When the Control Temperature is warmer than the zone cooling set point, cooling is staged up; when the Control Temperature is cooler than the zone cooling set point, cooling is staged down. However, a stage change can occur only when the Control Temperature is outside the dead band. Staging is constrained by an inter-stage delay timer (5-minute default setting) and minimum and maximum discharge air temperature limits (all keypad programmable). These constraints protect the compressors from short cycling while eliminating temperature variations near the diffusers.

Project Ahead Algorithm

The inherent lag effect in zone temperature control applications can cause overshoot during warm-up or cool-down periods. MicroTech II features a unique “Project Ahead” control algorithm that eliminates this overshoot by calculating the rate at which the Control Temperature is changing and reducing the unit’s cooling or heating output as the zone temperature nears its set point. A separate, keypad-programmable Project Ahead time parameter provides fine tuning for both heating and cooling.

Duct Static Pressure Control On all DAC units, duct static pressure control is maintained by the PID algorithm, which provides precise control of the supply fan variable frequency drive or inlet vanes. The keypad-programmable set point can be set between 0.20'' wc and 4.00" wc.

An optional second duct static sensor is available for larger buildings with multiple trunk runs or large shifts in load due to solar effects (east/west building orientation). The MicroTech II controller automatically selects and uses the lower of the two sensed pressures to control fan volume. This feature provides that adequate static pressure is supplied to the most demanding space at all times.

Multiple Unit Applications

For applications in which multiple units are connected in a common duct system, it is important to control all units from a common duct static pressure sensor and to control all operating units in unison. Centralized duct static pressure control can be accomplished through communication with the BAS network.

McQuay Cat 860-7 19


Operating States Operating states define the current overall status of the self-contained system. At the user interface, the operator can display the current operating state and thereby quickly assess the unit’s operating condition. Figure 13 shows all the possible operating states and the status information they summarize. Depending on unit options, some operating states may not apply. For example, a 100% outside air unit does not have a Morning Warm-Up, Economizer, or Unoccupied Economizer operating state.

Figure 13: Operating State sequence Chart

Fan only

Economizer

UnocEcon

UnocClg Cooling

Heating

MWU

Min DAT

Recirculate

Startup

UnocHtg

OffAny State

20 McQuay Cat 860-7

Alarm Management and Control MicroTech II unit controllers are capable of sophisticated alarm management and controlled response functions. Each alarm that occurs is prioritized, indicated, and responded to with the appropriate action. The current alarm (up to four alarms, arranged by alarm priority) and previous alarm (up to eight alarms, arranged by date/time cleared), each with a time and date stamp, can be displayed at the user interface. Whenever a current alarm is cleared, it is logged as a previous alarm and all events in memory are shifted. The current alarm becomes the new previous alarm, and the oldest previous alarm is removed.

Alarm Priority

The various alarms that can occur are prioritized according to the severity of the problem. See Table 1. Three alarm categories are used: faults, problems, and warnings. 1 Faults are the highest priority alarms. If a fault condition

occurs, the complete unit shuts down until the alarm condition is gone and the fault is manually cleared at the keypad. A fault example is Fan Fail alarm.

2 Problems are the next lower priority to alarms. If a problem occurs, the complete unit does not shut down, but its operation is modified to compensate for the alarm condition. A problem automatically clears when the alarm condition that caused it is gone. Compressor Fail is an example of a problem where only the affected compressor is shut down.

3 Warnings are the lowest priority alarms. No control action is taken when a warning occurs; it is indicated to alert the operator that the alarm condition needs attention. To make sure that they are read, the operator must manually clear all warnings. Dirty Filter indication is an example of a warning.

Generally, a specific alarm condition generates an alarm that falls into only one of these categories. Under different sets of circumstances, however, the freezestat and most of the sensor failure alarm conditions can generate alarms that fall into multiple categories.

Adjustable Alarm Limits

Four alarm indications have adjustable limits that are used to trigger the alarm. The high return temperature alarm and the high and low supply temperature alarms are adjusted at the user interface. The dirty filter alarm(s) is adjusted at the sensing device.

Personal Computer Based ServiceTools™

A personal computer (PC) can be equipped with Windows®-based Service Tools™ software to provide a high level operator interface with the MicroTech II unit controls for expanded diagnostic and service capability. The PC can be connected directly to the MicroTech II controller or used remotely with the addition of an optional unit-mounted phone modem.

Table 1: MicroTech II Alarm SummaryAlarm Name Fault Problem Warning

Freeze X X

Smoke X

Temperature Sensor Fail X X

Duct High Limit X

High Return Temp X

High Discharge Temp X

Low Discharge Temp X

Fan Fail X

Fan Retry X

Discharge Air Capacity Feedback X

Economizer Stuck X X

Auxiliary Control Board Enable X

Auxiliary Control Board Communications X

Low Airflow X

Heat Fail X

Circuit 1–6 High Pressure X

Circuit 1–6 Low Pressure/Frost X

Compressor 1–6 Motor Protection X

Compressor 1–6 Fail X

Auxiliary Control Board Enable Hardware X

Airflow Switch (False Airflow) X

Dirty Filter X

McQuay Cat 860-7 21

Application Considerations

Application ConsiderationsThis section contains basic application and installation guidelines to consider as part of the detailed analysis of any project.

GeneralUnits are intended for use in normal heating, ventilating, and air conditioning applications. Consult your local McQuay sales representative for • Applications involving operation at high entering condenser

water temperatures; high altitudes; or noncataloged voltages.• Applications requiring modified or special control sequences.• Job-specific unit selections that fall outside of the range of

the catalog tables, such as 100% outside air applications.

For proper operation, rig units following instructions in IM 708. If fire dampers are required, install them in the ductwork according to local codes. Space is not provided for these dampers in the unit.

Explicitly follow factory check, test, and start procedures for satisfactory start-up and operation (see IM 708).

Many self-contained system applications take advantage of the significant energy savings provided by the use of economizer operation. When a water economizer system is used, mechanical refrigeration typically is not required below an entering condenser water temperature of 55°F. Standard McQuay self-contained systems are designed to operate with entering water temperatures down to 50°F when a water economizer is used and 55°F with no water economizer. For applications where a water economizer system cannot be used, a modulating head pressure control system is available to permit operation at entering condenser water temperatures below 55°F.

Unit LocationThe floor must be structurally strong enough to support the unit with minimum deflection (see “Unit Weights” on page 62). Provide proper structural support to minimize sound and vibration transmission. Consider a concrete floor. Extra design consideration is required when installing on a wooden structure. Install units level from front-to-back and over their length.

Locate unit fresh air intakes away from building flue stacks, exhaust ventilators, and areas containing automotive or other exhaust to prevent the possible introduction of contaminated air to the system. Consult code requirements for minimum fresh air volumes.

Allow sufficient space around the unit for service and maintenance clearance. Refer to Figure 14 for recommended service/maintenance clearances and “Recommended Clearances” on page 58. Locate equipment room access doors in a manner that can assist in service access if needed (e.g., coil removal). Contact your local McQuay sales representative if reduced service/maintenance clearances are required.

Where code considerations such as the NEC require extended clearances, they take precedence over minimum service/maintenance clearances.

Acoustical ConsiderationsGood acoustical design is a critical part of any successful installation and should start at the earliest stages in the design process. Each of the four common sound paths must be addressed. They are:• Radiated sound through the casing of the unit• Structure-borne vibration• Airborne sound through the supply air duct• Airborne sound through the return air duct

Basic guidelines for good acoustical performance include:1 Always provide proper structural support under the unit.2 Provide adequate mass in the floor structure, especially

when located over an occupied space where good acoustics are essential.

3 Seal all supply and return air duct penetrations once the duct is installed.

4 Don’t overlook the return air path. Always include some duct work (acoustically-lined tee) at the return inlet.

5 Minimize system static pressure losses to reduce fan sound generation.

6 Select the appropriate unit/fan for the application. Select fans as close as possible to their peak static efficiency. To assist you, peak static efficiency is identified by the first system curve to the right of the shaded “Do not select” region on each fan curve. See pages 49–54.

7 Design duct systems to minimize turbulence. 8 Account for low frequency duct breakout noise in system

design. Route the first 20' of rectangular duct over nonsensitive areas and avoid large duct aspect ratios. Consider round or oval duct to reduce breakout.

Figure 14: Recommended Service/Maintenance Clearances

* If water and condensate drain connections are left-hand, 36” is required.

Airflow 24"

42"

Evaporator Coil

Compressors 36"24"or

36"

1

AFD Electrical Panel

Left Side

Right Side

Front

Back

CondenserCleanout

3 5 6 4 2

Motor

22 McQuay Cat 860-7


Equipment RoomLocate the equipment room away from sound sensitive areas. Whenever possible, isolate the equipment room from these areas by locating restrooms, utility rooms, stairwells, hallways, elevators, etc. around its perimeter. This allows not only isolation from radiated sound but provides the capability to route ductwork over less sensitive areas.

Acoustically seal the equipment room with a high quality, flexible material to prevent air and noise from escaping. Even a small leak compromises the acoustic performance of the installation. Design the equipment room door to seal tightly on a perimeter gasket.

Equipment room wall construction should be concrete block or offset, double stud. The decision depends on the critical nature of the application. If offset, use double stud construction. Line the cavity with glass fiber insulation and use a double layer of wallboard on each side of the wall.

DuctworkFan noise travels through the ductwork to occupied spaces; it likely is the most challenging to control. Careful duct design and routing practice is required. The ASHRAE Applications Handbook discusses sound attenuation relevant to self-contained system applications. Advances in acoustical science allow for designing sound levels in a given space if equipment sound power data is available. Contact your local McQuay sales representative for sound power data for your specific application.

Return Duct

The return duct is often overlooked. Duct return air directly to the unit or into the equipment room. If ducted to the equipment room, install an elbow within the equipment room. Running a return air drop near the floor of the room provides added attenuation. Extend a length of lined ductwork from the equipment room to a length of 15 feet. The maximum recommended return air duct velocity is 1000 feet per minute.

Supply Duct

Extend a lined section of supply air duct at least 15 feet from the equipment room. Using round duct significantly reduces low frequency sound near the equipment room. If rectangular duct is used, keep the aspect ratio of the duct as small as possible. The large flat surfaces associated with large aspect ratios transmit sound to the space and increase the potential for duct generated noise such as oil canning. The maximum recommended supply air duct velocity is 2000 feet per minute.

Factory-designed and factory-built acoustic discharge plenums are available with multiple outlets to minimize difficult transitions, tight radius duct connections, and the sound compromises they can cause. Multiple factory-fabricated outlet opening sizes are available as well as multiple openings in a single plenum. Determine fan discharge orientation so a front or back outlet allows the air to turn in the direction of fan rotation. If directly ducting to the fan outlet, allow a minimum of two fan diameters from the fan outlet; the elbow should turn in the direction of fan rotation. Avoid abrupt turns, takeoffs, etc.; they generate air turbulence, resulting in unwanted sound.

Duct Protection

An adjustable duct high limit switch is standard equipment on all SWP systems with VAV controls. This is of particular importance when using fast-acting, normally closed boxes. The switch is field adjustable; set it to meet the specific rating of the system ductwork.

Vibration Isolation

Make duct connections to the unit or to the acoustic discharge plenum with a flexible connection. Though flexible piping and electrical connections are not required, pay attention to these areas to avoid vibration transmission from outside sources to the SWP unit.

Condenser Water PipingAlways follow good industry practice in the water piping system design. Attention to water treatment and proper strainer application are always necessary. All SWP systems feature mechanically cleanable condensers and optional waterside economizer coils. In addition to mechanically cleanable heat exchangers, cleanouts are provided in the interconnecting piping and in the internal condensate drain trap. Costly field traps are not required. To allow periodic cleaning of the condensers and economizer coils, provide isolation valves. Condensers, economizer coils and hot water coils are provided with vent and drain connections.

Always review for possible requirements for condenser piping insulation, especially if cold entering condenser water conditions (<55°F) will be experienced.

Head Pressure ControlIf cold entering condenser water conditions (<55°F) will be experienced, use a waterside economizer or a condenser head pressure control valve. A two-way, head pressure activated control valve is available factory installed for these applications. The head pressure control allows entering condenser water temperatures as low as 40°F. A head pressure control valve is not required when the SWP unit is applied with a factory waterside economizer package.

McQuay Cat 860-7 23


Variable Air VolumeMcQuay SWP units offer variable frequency drives for fan speed control. VFDs offer reliable operation over a wide range of airflow, with variable frequency drives offering advantages in sound and energy performance. In addition, McQuay offers the ability to sense duct static pressure in multiple locations, enhancing control accuracy and helping minimize energy use.

Variable Frequency Drives

Variable frequency drives provide the most efficient means of variable volume control by taking advantage of the fan law relation between fan speed (rpm) and fan brake horsepower (bhp). Also, since airflow reduction is accomplished by changing fan speed, the noise penalties often associated with mechanical control devices, e.g., inlet vanes, are not introduced. The following equation illustrates how fan bhp varies as the cube of the change in fan speed:

In an ideal system, at 50% fan speed, brake horsepower is reduced to 12.5% of that at full speed.

Variable frequency control varies the speed of the fan by adjusting the frequency and voltage to the motor. Keeping a constant volts/frequency ratio (constant magnetic flux) to the motor allows the motor to run at its peak efficiency over a wide range of speeds and resulting fan airflow volumes.

Duct Static Pressure Sensor PlacementStatic pressure should be sensed near the end of the main duct trunk(s). Adjust the MicroTech II static pressure control so that at full airflow all of the terminals receive the minimum static pressure required plus any downstream resistance. Control is to the lowest static pressure set point that satisfies airflow requirements. Lower static pressure set points reduce fan brake horsepower requirements and fan sound generation.

Locate the static pressure sensor tap in the ductwork in an area free from turbulence effects and at least 10 duct diameters downstream and several duct diameters upstream from any major interference, including branch takeoffs. The SWP MicroTech II control system can receive a second duct static pressure sensor in installations having multiple duct trunks or significantly varying zones. The control logic maintains static pressure at both sensors.

Zone Sensor PlacementPlacement of the zone temperature sensor is extremely important to provide proper and economical operation of the heating and cooling system. Generally, McQuay recommends locating the space sensor on an inside wall (3 to 5 feet from an outside wall) in a space having a floor area of at least 400 square feet. Do not locate the sensor below the outlet of a supply air diffuser, in the direct rays of the sun, on a wall adjacent to an unheated or abnormally warm room (boiler or incinerator room), or near any heat producing equipment. Where zone sensor placement is a problem, all SWP zone control systems have, as standard, the capability to use the return air sensor for heating and cooling control.

Filtration Routinely replace filters to minimize filter loading. As filters get dirty, the filter pressure drop increases, affecting system airflow and energy requirements. Depending on fan type, forward curved or airfoil, this airflow change can be significant. The effect of filter loading is the most critical when using high efficiency filters.

When making a fan selection, include a pressure drop component in the system total static pressure to account for dirty filters. Use a value midway between clean and dirty filter ratings. If a minimum airflow is critical, make the fan selection using the higher, dirty filter pressure drop value. For VAV systems, consider setting the fan control device so part of its modulation range can be used to maintain airflow as filters become dirty. Following these recommendations should limit airflow fluctuation as the filters load.

System Operating LimitsSWP units can be applied in a wide range of system needs. High cfm/ton or high/low discharge temperature applications are available. However, for proper system operation, some application limits do apply.

Airflow

Maximum cfm limits based on coil face velocity are listed in the Physical Data table on page 29.

Separate minimum design cfm limits by unit size are listed in the physical data table for constant and variable air volume applications. Limit fan modulation to 40% of the minimum design cfm limit. Minimum airflow conditions are dependent on fan selection criteria also. Contact your McQuay sales representative to answer questions on minimum airflow capability or for conditions not shown in this catalog.

VAV box minimum airflow settings should correspond with the minimum VAV fan operating point. All units are provided with multigroove, fixed pitch sheaves. During system air balance, alternate fixed pitch sheaves may be needed to match final system requirements. Alternate sheaves are available from McQuay.

hp2 hp1density2density1---------------------⎝ ⎠⎛ ⎞ rpm2

rpm1------------⎝ ⎠⎛ ⎞

3=

24 McQuay Cat 860-7

Fan Heat

Sensible heat gain from the fan, fan motor, and drives occurs in all fan systems; consider its effect during equipment selection. It is an added load in cooling and an added source when in heating. The majority of the heat gain occurs through the fan itself, as the air elevates from the low-pressure side to the high-pressure side of the fan. Moving the motor out of the air stream has a negligible effect on overall fan heat gain. A unit with higher fan power requirements/higher fan heat has less net cooling capability and may not have enough left to satisfy system loads.

As a rule, typical supply fan heat gain is 3°F. However, fan heat gain can be calculated quickly once the fan is selected and the fan brake horsepower is determined. Using Figure 15, select your fan brake horsepower on the horizontal axis and move up vertically until you intersect with the heat gain curve. Then move horizontally to find the fan heat gain in MBh.

Figure 15: Fan and Motor Heat Gain

A draw-through unit has the fan located after the DX cooling coil. In this arrangement, fan heat is applied as reheat to the cold, conditioned air coming off of the coil. This arrangement has a lower sensible heat ratio and higher dehumidification capability than a blow-through coil arrangement. The discharge temperature available to the supply duct is always the sum of the coil leaving air temperature plus the fan temperature rise. Consider this when selecting the supply air volume required to satisfy space requirements.

Example: 52°F leaving coil temperature + 3°F fan temp. rise =

55°F discharge air temperature

Condenser Water Flow

System capacity tables provide selections for a condenser flow rate of 3 gpm/ton. For a given entering condenser water temperature, 3 gpm/ton provides maximum unit performance. Reducing condenser water flow rates to 2.5 or 2 gpm/ton can significantly reduce pumping energy costs and reduce piping costs. Compare and evaluate the reduction in pumping energy to the change in unit performance. Use the SWP capacity tables (Table 8 on page 32) for condenser flow rates from 2 to 3 gpm/ton, using the appropriate leaving condenser water temperature column (interpolation is allowed). The minimum condenser flow rate is 2 gpm/ton.

Coil Freeze ProtectionAlways consider coil freeze protection when applying units in geographic areas that experience subfreezing temperatures. Careful design of outside air/return air mixing systems is critical to minimizing freeze potential. Some applications may require using glycol and/or preheat coils. No control sequence can prevent coil freezing in the event of power failure.

A nonaveraging freezestat control is factory installed on all units with hot water heat or a waterside economizer. If a potential freeze condition is sensed, unit water valves are driven to the full open position, the supply fan de-energizes, and an alarm is indicated.

In nonducted return applications, where the equipment room is the mixing plenum, consider some form of heat within the equipment room.

Air Density CorrectionFan performance data is based on standard 70°F air temperature and zero feet altitude (sea level). For applications other than standard, multiply the density ratio to actual static pressure values. Density correction factors are expressed as a function of temperature and altitude in Table 2.

Fan temperature rise = (fan heat (MBh)

(1.085 × fan cfm)

Table 2: Temperature and Altitude Conversion Factors

Air temp

Altitude (feet)

0 1000 2000 3000 4000 5000 6000 7000 8000

–20°F 1.20 1.16 1.12 1.08 1.04 1.00 0.97 0.93 0.89

0°F 1.15 1.10 1.08 1.02 0.99 0.95 0.92 0.88 0.85

20°F 1.11 1.06 1.02 .098 0.95 0.92 0.88 0.85 0.82

40°F 1.06 1.02 0.98 0.94 0.91 0.88 0.84 0.81 0.78

60°F 1.02 0.98 0.94 0.91 0.88 0.85 0.81 0.79 0.76

70°F 1.00 0.96 0.93 0.89 0.86 0.83 0.80 0.77 0.74

80°F 0.98 0.94 0.91 0.88 0.84 0.81 0.78 0.75 0.72

100°F 0.94 0.91 0.88 0.84 0.81 0.78 0.75 0.72 0.70

120°F 0.92 0.88 0.85 0.81 0.78 0.76 0.72 0.70 0.67

140°F 0.89 0.85 0.82 0.79 0.76 0.73 0.70 0.78 0.65

McQuay Cat 860-7 25


Unit WiringAll units require 3-phase, 60 Hz, 208, 230, 460, or 575 volt power or 3-phase, 50 Hz, 400-volt power. Units will operate satisfactorily at ±10% of rated voltage at the power connection terminals of the unit. All units include individual branch circuit fusing of all motor loads and have a single-point power connection. A factory-mounted, nonfused disconnect switch is an available option. Install all wiring in accordance with the NEC and local codes.

Terms of SaleAll products are offered pursuant to McQuay’s standard terms and conditions of sale including limited product warranty, which can be accessed at www.McQuay.com.

26 McQuay Cat 860-7

Selection ProcedureAchieving the optimal performance of any system requires both accurate system design and proper equipment selection. Factors that control unit selection include applicable codes, ventilation and filtration requirements, heating and cooling loads, acceptable temperature differentials, and installation limitations. McQuay SWP units offer a wide selection of component options providing the capability to meet diverse application needs.

The McQuay SelectTools™ software selection program allows your local McQuay sales representative to provide you with a fast, accurate, and complete selection of McQuay SWP units. Unit selection also can be accomplished through reference to physical, performance, dimensional and unit weight data included in this catalog. Due to the variety of cooling system options available, only a sampling of cooling capacity data is presented here.

To properly select equipment, follow these steps: 1 Select the unit size and compressor combination.2 Select the heating system. 3 Select the fan and motor.

The following example illustrates the catalog selection procedure.

Selection Example:

Scheduled design requirements:

Summer design:

Winter design:

Step 1: Unit Size Selection

Unit size is based on coil face area and cooling capacity requirements. Use supply air capacity and maximum face velocity constraints as a guide for selecting coil dimensions and cabinet size.

Based on the given data, the appropriate coil face area is determined as follows:

Minimum face area = cfm/maximum face velocity= 21,000 cfm/550 fpm= 38.2 square feetNote – Unit data is based on standard air conditions of 70°F at

sea level. See “Application Considerations” on page 22 for temperature/altitude conversion factors for nonstandard conditions.

Referring to the “Physical Data” table on page 29, the 41.5 square foot coil of the SWP 065 satisfies the requirements.

Step 2: Unit DX Cooling Selection

Since the design cfm is less than the nominal value in the DX Cooling Capacity Data table, adjust the capacities per Table 7 on page 31.

cfm correction factor = design cfm/nominal cfm = 21,000 / 24,000 = 87.5%

Total heat correction multiplier = .978Capacity required from table = 750 MBh /.978 = 766.9 MBh

Sensible heat correction multiplier =.939 Capacity required from table = 575 MBh /.939 = 612.4 MBh

Using the “Performance Data” on page 36, the unit selection is a SWP 065 with (2) 13 hp and (2) 15 hp compressors. Unit performance from the table equals 805.1 TMBh / 614.5 SMBh at 190 gpm. Adjusting for the specified cfm yields:Total capacity = 805.1 MBh × .978 = 787.4 MBhSensible capacity = 614.5 MBh × .939 = 577.0 MBh Coil LAT = 80ºF – 577.0 MBh / (1.085 × 21,000 cfm) = 54.7°F

Condenser flow rate = 190 gpm × .978 = 185 gpm

Step 3: Economizer Capacity Selection

Determine waterside economizer capacity by referring to the appropriate table. See “Waterside Economizer Capacity” on page 40. Use entering air of 80/67°F and entering water of 55°F at 185 gpm. Interpolating for the required gpm, economizer performance equals 497.8 TMBh / 473.0 SMBh at the unit’s nominal cfm. See Table 6 on page 31, “Waterside Economizer Capacity Correction Factors,” to find performance at the specified cfm.

Total capacity = 497.8 MBh × 0.95 = 472.9 MBh

Sensible capacity = 473.0 MBh × 0.915 = 432.8 MBh

Supply air volume 21,000 cfmMaximum face velocity 550 fpm is chosen* Supply fan external SP 2.00" w.g.Altitude sea levelVariable air volume system with fan speed controlHot water heatWater economizer system 30% pleated filters460 V/60 Hz/3 PhDouble wall constructionR-22 refrigerantPremium efficiency motor*600 is the design limit per page Table 4 on page 29

DX coil mixed air dry bulb 80°FDX coil mixed air wet bulb 67°FSensible load 575,000 Btu/hrTotal load 750,000 Btu/hrSupply fan sensible heat 3°F riseEntering condenser water 85°FLeaving condenser water 95°FMinimum condenser water 55°F

Return air temperature 60°FSpace heating load 850 MBhEntering hot water temperature 180°F

McQuay Cat 860-7 27

Selection Procedure

Step 4: Heating Selection

Determine hot water capacity from Table 21 on page 44. After interpolating for the specified cfm, Table 21 indicates a capacity of 856.5 MBh.

Step 5: Fan/Motor Selection

Fan/motor selection is based on unit total static pressure and design airflow. Total static pressure includes the internal air pressure drops of unit components and external air pressure drops of supply and return air duct systems. See “Component Pressure Drops” on page 45 for internal pressure drops of unit components. Values in the table may be interpolated for the specified cfm.

Internal pressure drops:

External pressure drop:

Total static pressure = internal drops + external drops = 1.75" + 2.00"= 3.75" w.g.

Entering the fan curve for the SWP 065 at 21,000 cfm and 3.75" w.g. yields 24.5 required fan brake horsepower. A 25 horsepower motor can be selected.

Step 6: Calculating Unit Weight

Referring to Table 31 on page 62 for a SWP 065:

Unit weight = SWP basic unit + 30% filters + 6-row evaporator coil + economizer coil + water (econ. coil) + hot water coil + water (HW coil) + SAF motor + VFD + [(2) 13 hp, (2) 15 hp] compressors + water (condenser)

= 3406 + 79 + 642 + 648 + 168 + 200 + 49 + 266 + 50 + 1709 + 129

= 7,346 lbs.

Step 7: Supply Power Wiring

Supply power wire sizing for a unit is based on the circuit with the highest amperage draw. All electrical equipment is wired to a central control panel for either single or optional dual power connections. Refer to “Electrical Data” on page 59 for FLA and RLA ratings. Determine Minimum Circuit Ampacity (MCA) as follows:

MCA = [1.25 × RLA or FLA of largest motor] + [1.00 × RLA or FLA of all other loads] + [2 amps (controls)]

MCA = [1.25 × 30.5 amps] + [16 + 16 + 19 +19] + [2] = 110.1 ampsNote – If a unit is selected with non-concurrent electric heat,

calculate the MCA for both the heating mode and the cooling mode and the larger value used.

R-407C vs. R-22

The cooling tables (Table 7 on page 31 and Table 8 on page 32) document the R-22 cooling capacity and compressor kW. The R-407C performance correction factors vary slightly with the unit size and operating conditions but can be estimated as shown in the table below. Use the McQuay SelectTools™ computer selection program to obtain the exact R-407C performance.

DX coil (wet surface) 0.87" w.g.Economizer coil (dry surface) 0.50" w.g.Hot water coil 0.16" w.g.4", 30% efficient filters 0.22" w.g.Total internal pressure drop 1.75" w.g.

Supply + return duct 2.00" w.g.

RLA/FLA(2) 13 horsepower compressors 16.0 amps each(2) 15 horsepower compressors 19.0 amps each25 horsepower premium efficiency supply fan motor

30.5 amps

Table 3: R-407C Correction Factor

Compressor type Compressor capacity Compressor kW

Scroll 0.96 - 0.98 1.02 - 1.04

Reciprocating 0.98 - 1.00 1.03 - 1.05

28 McQuay Cat 860-7

Physical Data

Physical Data

Table 4: SWP 018D Through SWP 105E

Data SWP model size

018 023 028 035 040 045 055 065 070 080 095 105Compressor

Quantity 3, 4 3, 4 4 4 4 4 4 4 4 4 4, 6 6Size See DX cooling capacity tables

Evaporator coilFace area (ft2) 11.8 15.3 17.7 23.3 27.7 30.7 36.1 41.5 46.3 51.1 55.9 63.2

High capacity and standard capacity DX coil offered.Fpi 12 12 12 12 12 12 12 12 12 12 12 12

Performancea

a. Based on ARI 340/360-93 standard rating conditions, 80/67°F to the coil, 85°F–95°F condenser water.

EER See Table 5 on page 30.Waterside economizer coil

Face area (ft2) 11.8 15.3 17.7 23.3 27.7 30.7 36.1 41.5 46.3 51.1 55.9 63.2Rows 4 4 4 4 4 4 4 4 4 4 4 4FPI 12 12 12 12 12 12 12 12 12 12 12 12

Maximum wkg. press. (psig) 400 400 400 400 400 400 400 400 400 400 400 200

Hot water heating coilFace area (ft2) 9.3 12.8 15.2 20.2 24.5 26.8 30.4 35.8 39.9 44.4 48.3 51.9

Rows 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1 1 1Fpi 12 12 12 12 12 12 12 12 12 12 12 12

Electric heatkW 34 34 34 34 34 68 68 68 68 68 68 68

Filters

(Quantity) size 4” depth filters

(6) 20 × 20

(2) 25 × 20

(6) 20 × 20

(2) 25 × 20

(6) 20 × 20

(2) 25 × 20

(10) 25 × 20

(10) 25 × 20

(12)25 × 20

(12) 25 × 20

(18)20 × 20

(6) 16 × 20

(12) 25 × 20

(3)20 × 20

(15) 25 × 20

(6) 16 × 20(15)

25 × 20

(4) 16 × 20

(17) 20 × 25

(1) 16 × 25

Evaporator fanb

b. Standard fan TSP limit is 5.5 inches of water. Consult your local McQuay sales representative for applications beyond this range.

Quantity 1 1 1 1 1 1 1 1 1 1 1 1Size 15 18 18 20 20 22 25 25 25 27 27 33

Min. horsepower 5 7.5 10 10 15 15 20 20 20 25 30 30Max. horsepower 10 15 20 20 25 30 40 40 40 50 60 60

Min. design cfm, CV 2950 3825 4425 5825 6925 7675 9025 10375 11575 12775 13975 15800Min. design cfm,

VAV 4720 6120 7080 9320 11080 12280 14440 16600 18520 20440 22360 25280

Max. design cfm 7080 9180 10620 13980 16620 18420 21660 24900 27780 30660 33540 37920Condenser

Waterside wkg. press. (psig) 400 400 400 400 400 400 400 400 400 400 400 400

Min. entering temp. (°F) mech. cooling 55 55 55 55 55 55 55 55 55 55 55 55

Minimum GPM 25 41 53 66 69 94 105 105 121 134 138 180Maximum GPM 88 108 125 159 166 215 237 237 251 349 358 493

McQuay Cat 860-7 29

R22 Unit Efficiency Ratings

Notes:1. Based on ARI 340/360-93 standard rating conditions as well as the best

DX coil and supply fan.2. All two-circuit units are available also with four circuits. EER is virtually the

same for both. Check with your sales representative for exact four-circuit EER.

Table 5: R22 Unit Efficiency RatingsModel Compressors # Circuits Gross MBh EER

018 3 × 6 3 243 12.90

018 4 × 6 2 295 13.32

023 3 × 6 3 246 13.94

023 4 × 6 2 305 14.21

023 4 × 7 2 342 13.95

023 1010 66 4 394 12.83

028 4 × 7 2 346 14.18

028 4 × 8 2 372 13.20

035 4 × 8 2 382 14.16

035 4 × 9 2 460 13.83

035 4 × 10 2 519 13.19

040 4 × 9 2 470 14.47

040 4 × 10 2 532 13.89

040 1313 1010 4 573 12.81

045 4 × 13 2 652 13.43

045 1515 1313 2 706 13.32

055 1313 1010 2 617 14.40

055 4 × 13 2 663 13.94

055 1515 1313 2 718 13.86

055 4 × 15 2 791 13.78

065 4 × 13 2 670 14.14

065 1515 1313 2 730 14.10

065 4 × 15 2 804 14.04

070 1515 1313 2 739 14.25

070 4 × 15 2 814 14.22

070 2020 1515 4 967 12.73

080 4 × 15 2 822 14.64

080 2020 1515 4 976 13.02

080 6 × 13 6 994 14.37

080 3 × 15 + 3 × 13 6 1084 14.08

095 2020 1515 4 991 12.99

095 4 × 20 4 1104 11.57

095 6 × 13 6 1031 14.43

095 3 × 15 + 3 × 13 6 1112 14.18

095 6 × 15 6 1202 14.11

105 6 × 15 6 1211 14.64

105 3 × 20 + 3 × 15 6 1380 12.31

30 McQuay Cat 860-7

Physical Data

Correction Multipliers

50 Hertz

For 50 Hz applications, derate the total capacity by 0.89 and the sensible capacity by 0.94. Base the 50 Hz supply fan motor horsepower selections on fan brake horsepower (from Figure 23 through Figure 33) divided by 0.8.

Table 6: Waterside Economizer Capacity Correction Factorscfm compared to rated quantity Total cooling capacity multiplier Sensible cooling capacity multiplier

Waterside economizer

–20% 0.920 0.870

–10% 0.960 0.930

Standard 1.000 1.000

+10% 1.04 1.06

+20% 1.08 1.12

Table 7: DX Cooling Capacity Correction Multipliers

Description Percent Standard cfm

–20% –15% –10% –5% Std. +5% +10% +15% +20%

Total heat 0.968 0.971 0.985 0.991 1.000 1.006 1.012 1.019 1.025

Sensible heat 0.900 0.925 0.952 0.974 1.000 1.024 1.048 1.070 1.093

Compressor motor kW 0.980 0.985 0.989 0.995 1.000 1.004 1.006 1.011 1.017

McQuay Cat 860-7 31

Performance Data

Performance DataDX Cooling Capacity DataTable 8: DX Cooling Capacity Data

Unit/Description DX cooling capacity

SWP 018F EDB (°F) EWB (°F) EWT (°F) TMBH SMBH LDB LWB GPM

4 x 6 hp compressors5-row DX coil

7000 cfmR-22

75 62

75 292 216 46.7 46.7 70

85 283 212 47.3 47.2 69

95 273 207 47.9 47.8 69

80 67

75 319 214 52 51.9 75

85 309 210 52.5 52.5 74

95 298 205 53.1 53 74

85 72

75 347 211 57.4 57.3 80

85 337 207 57.9 57.8 80

95 326 203 58.4 58.3 80


4 × 6 hp compressors5-row DX coil

8000 cfmR-22

75 62

75 308 235 48 48 73

85 298 231 48.5 48.5 72

95 287 226 49.1 49.1 72

80 67

75 335 233 53.3 53.3 78

85 325 229 53.8 53.8 78

95 314 224 54.3 54.3 77

85 72

75 366 230 58.7 58.6 85

85 355 226 59.1 59.1 84

95 343 221 59.6 59.6 83


4 × 7 hp compressors5-row DX coil

8000 cfmR-22

75 62

75 337 249 46.5 46.5 81

85 327 244 47 47 80

95 314 238 47.7 47.7 79

80 67

75 368 246 51.7 51.7 87

85 357 242 52.3 52.3 85

95 344 236 52.9 52.9 85

85 72

75 401 243 57.2 57.2 93

85 389 238 57.7 57.6 91

95 376 233 58.2 58.2 91


4 × 7 hp compressors5-row DX coil10,000 cfm

R-22

75 62

75 356 281 49.2 49.2 84

85 345 276 49.7 49.6 84

95 331 270 50.3 50.2 82

80 67

75 388 278 54.5 54.5 91

85 376 273 55 54.9 90

95 362 267 55.5 55.4 88

85 72

75 422 274 59.9 59.8 97

85 409 269 60.3 60.2 96

95 394 264 60.8 60.7 95

Notes: See Table 7 on page 31 to determine unit capacity at other than nominal cfm.For a computer-generated, job-specific selection, contact your local McQuay sales representative.For 50 Hz applications, derate the total capacity by 0.89; derate the sensible capacity by 0.94.All capacities are gross and do not account for fan motor heat.Altitude and/or glycol selections are also available.

32 McQuay Cat 860-7

Performance Data



R-22

75 62

75 376 290 48.4 48.4 90

85 363 284 49 48.9 89

95 350 278 49.5 49.4 88

80 67

75 412 288 53.6 53.6 97

85 398 282 54.1 54.1 96

95 384 276 54.6 54.6 94

85 72

75 452 285 58.9 58.8 105

85 437 279 59.4 59.3 104

95 422 274 59.9 59.8 102



R-22

75 62

75 398 324 50.2 50.2 95

85 384 318 50.7 50.6 93

95 369 312 51.2 51.1 92

80 67

75 436 322 55.4 55.3 102

85 421 316 55.8 55.8 100

95 405 310 56.3 56.3 99

85 72

75 478 319 60.6 60.6 110

85 461 313 61.1 61 108

95 444 307 61.5 61.5 107



R-22

75 62

75 462 353 48 48 110

85 446 346 48.6 48.6 108

95 429 338 49.2 49.1 107

80 67

75 506 350 53.2 53.2 118

85 488 343 53.8 53.8 117

95 470 336 54.3 54.3 115

85 72

75 554 346 58.5 58.5 128

85 535 339 59 59 126

95 514 332 59.6 59.6 124



R-22

75 62

75 517 390 47.5 47.5 123

85 500 382 48.1 48 122

95 481 373 48.7 48.6 122

80 67

75 567 387 52.7 52.7 133

85 547 379 53.3 53.2 132

95 527 370 53.9 53.8 130

85 72

75 620 383 58 58 144

85 599 375 58.6 58.5 142

95 577 366 59.1 59.1 140

Notes: SeeTable 7 on page 31 to determine unit capacity at other than nominal cfm.For a computer-generated, job-specific selection, contact your local McQuay sales representative.For 50 Hz applications, derate the total capacity by 0.89; derate the sensible capacity by 0.94.All capacities are gross and do not account for fan motor heat.Altitude and/or glycol selections are also available.

Table 8: DX Cooling Capacity Data (continued)Unit/Description DX cooling capacity

McQuay Cat 860-7 33

Performance Data



R-22

75 62

75 483 387 49.6 49.6 114

85 466 379 50.1 50.1 113

95 448 371 50.7 50.6 111

80 67

75 529 384 54.8 54.8 123

85 510 376 55.3 55.3 121

95 490 369 55.8 55.8 120

85 72

75 579 380 60.1 60.1 133

85 558 373 60.6 60.6 131

95 536 365 61.1 61.1 129



R-22

75 62

75 536 411 48.1 48.1 127

85 518 402 48.6 48.6 126

95 498 393 49.2 49.2 125

80 67

75 587 407 53.3 53.3 137

85 567 399 53.8 53.8 135

95 545 390 54.4 54.4 133

85 72

75 643 403 58.6 58.6 148

85 621 395 59.1 59.1 146

95 596 386 59.7 59.7 144

SWP 040D EDB (°F) EWB (°F) EWT (°F) TMBH SMBH LDB LWB GPM

2 × 10 + 2 × 15 hp compressors6-row DX coil16,000 cfm

R-22

75 62

75 580 454 49 48.9 139

85 561 446 49.5 49.4 137

95 541 437 50 49.9 137

80 67

75 632 450 54.2 54.2 150

85 612 441 54.7 54.6 148

95 590 432 55.2 55.1 146

85 72

75 690 444 59.5 59.5 161

85 667 436 60 59.9 159

95 643 427 60.5 60.4 157



R-22

75 62

75 656 512 48.9 48.9 157

85 634 502 49.4 49.3 156

95 612 492 49.9 49.8 154

80 67

75 718 508 54.1 54.1 170

85 694 498 54.6 54.5 168

95 669 488 55.1 55 166

85 72

75 787 503 59.4 59.3 183

85 760 493 59.9 59.8 180

95 733 483 60.4 60.3 178



34 McQuay Cat 860-7

Performance Data



R-22

75 62

75 707 535 47.7 47.7 169

85 684 524 48.3 48.2 167

95 660 513 48.8 48.8 166

80 67

75 773 530 53 52.9 182

85 748 520 53.5 53.4 180

95 722 509 54 54 179

85 72

75 846 525 58.3 58.2 197

85 819 515 58.8 58.7 195

95 790 504 59.3 59.3 192



R-22

75 62

75 678 546 49.9 49.9 162

85 655 536 50.4 50.3 160

95 631 526 50.9 50.8 157

80 67

75 742 542 55.1 55.1 174

85 717 532 55.6 55.5 172

95 691 522 56.1 56 170

85 72

75 813 537 60.4 60.3 188

85 785 527 60.8 60.8 185

95 755 517 61.3 61.2 182



R-22

75 62

75 732 571 48.8 48.8 174

85 708 560 49.3 49.3 173

95 683 548 49.8 49.8 171

80 67

75 801 566 54 54 189

85 774 555 54.5 54.5 186

95 747 544 55 55 184

85 72

75 875 559 59.3 59.3 203

85 846 549 59.8 59.8 200

95 816 538 60.3 60.3 197



R-22

75 62

75 796 611 48.3 48.2 189

85 771 600 48.8 48.7 187

95 743 587 49.4 49.3 186

80 67

75 870 606 53.5 53.5 204

85 842 594 54 54 201

95 812 582 54.6 54.5 199

85 72

75 950 598 58.9 58.8 220

85 920 587 59.3 59.3 218

95 888 576 59.9 59.8 215



McQuay Cat 860-7 35

Performance Data



R-22

75 62

75 696 579 50.8 50.8 166

85 672 569 51.3 51.2 163

648 558 51.7 51.6 161

80 67

75 761 575 56 56 178

85 735 565 56.4 56.4 175

95 708 554 56.9 56.8 173

85 72

75 834 570 61.2 61.2 193

85 805 560 61.7 61.6 189

95 774 549 62.1 62 187



R-22

75 62

75 753 605 49.8 49.7 179

85 728 594 50.2 50.2 177

95 702 582 50.7 50.7 174

80 67

75 823 600 55 55 193

85 796 589 55.5 55.4 190

95 767 577 55.9 55.9 188

85 72

75 899 593 60.3 60.2 208

85 869 582 60.7 60.7 205

95 838 571 61.2 61.1 202



R-22

75 62

75 814 632 48.7 48.6 193

85 787 620 49.2 49.1 190

95 758 607 49.7 49.6 189

80 67

75 889 626 53.9 53.9 209

85 860 614 54.4 54.3 206

95 829 602 54.9 54.9 202

85 72

75 969 618 59.2 59.2 224

85 939 607 59.7 59.7 221

95 906 595 60.2 60.1 218



R-22

75 62

75 771 638 50.6 50.6 183

85 745 626 51.1 51 180

95 717 614 51.5 51.5 178

80 67

75 842 632 55.8 55.8 197

85 813 621 56.3 56.2 194

95 783 609 56.7 56.7 191

85 72

75 920 625 61.1 61.1 212

85 889 614 61.5 61.5 209

95 856 603 61.9 61.9 206



36 McQuay Cat 860-7

Performance Data



R-22

75 62

75 834 665 49.6 49.5 198

85 806 653 50 50 195

95 776 640 50.5 50.5 192

80 67

75 910 659 54.8 54.8 213

85 880 647 55.3 55.2 210

95 848 635 55.7 55.7 207

85 72

75 992 651 60.1 60.1 229

85 961 640 60.5 60.5 226

95 926 627 61 61 222



R-22

75 62

75 991 771 48.8 48.7 240

85 949 752 49.4 49.3 235

95 908 733 50.1 50 231

80 67

75 1086 766 54 53.9 259

85 1040 747 54.6 54.5 253

95 995 729 55.2 55.1 248

85 72

75 1189 758 59.2 59.2 280

85 1139 740 59.9 59.8 274

95 1090 722 60.5 60.4 268



R-22

75 62

75 861 726 51.2 51.1 203

85 832 714 51.6 51.5 200

95 800 700 52.1 52 198

80 67

75 938 720 56.4 56.4 216

85 907 708 56.8 56.7 214

95 874 695 57.2 57.2 213

85 72

75 1022 711 61.7 61.6 235

85 989 700 62.1 62 232

95 952 687 62.5 62.4 228



R-22

75 62

75 1011 793 49 49 244

85 968 773 49.7 49.6 239

95 926 754 50.3 50.2 234

80 67

75 1107 787 54.2 54.2 263

85 1060 768 54.8 54.8 257

95 1013 749 55.5 55.4 252

85 72

75 1213 779 59.5 59.4 286

85 1161 761 60.1 60 279

95 1111 742 60.7 60.6 273



McQuay Cat 860-7 37

Performance Data



R-22

75 62

75 1037 827 49.7 49.5 245

85 1005 812 50.2 50 241

95 970 796 50.6 50.4 239

80 67

75 1129 819 54.9 54.8 263

85 1093 805 55.4 55.2 259

95 1055 789 55.9 55.7 256

85 72

75 1228 810 60.2 60.2 283

85 1188 795 60.7 60.6 279

95 1146 780 61.2 61 274



R-22

75 62

75 1113 862 48.6 48.5 263

85 1080 847 49.1 49 260

95 1044 830 49.6 49.4 258

80 67

75 1209 853 53.9 53.8 283

85 1173 838 54.4 54.3 279

95 1133 822 54.9 54.8 276

85 72

75 1318 843 59.2 59.2 304

85 1277 828 59.7 59.6 300

95 1233 812 60.2 60.1 296



R-22

75 62

75 1060 861 50.3 50.1 250

85 1027 846 50.7 50.5 246

95 991 830 51.2 51 243

80 67

75 1154 854 55.5 55.4 268

85 1117 839 56 55.8 264

95 1077 823 56.4 56.2 260

85 72

75 1255 844 60.8 60.7 289

85 1213 829 61.2 61.1 284

95 Do not select Do not select Do not select Do not select Do not select



R-22

75 62

75 1138 897 49.3 49.1 268

85 1104 881 49.7 49.6 265

95 1066 864 50.2 50 263

80 67

75 1236 888 54.5 54.5 289

85 1198 872 55 54.9 285

95 1158 856 55.5 55.3 282

85 72

75 1345 877 59.9 59.8 310

85 1303 861 60.3 60.2 305

95 1257 845 60.8 60.7 301



38 McQuay Cat 860-7

Performance Data

SWP 095D EDB EWB EWT TMBH SMBH LDB LWB GPM


R-22

75 62

75 1152 904 49.1 49 284

85 1092 877 49.8 49.7 275

95 1037 853 50.6 50.4 268

80 67

75 1267 900 54.2 54.1 307

85 1201 873 55 54.9 298

95 1140 849 55.7 55.6 290

85 72

75 1395 894 59.4 59.3 334

85 1322 867 60.1 60.1 324

95 1255 844 60.8 60.7 315

SWP 105E EDB (°F) EWB (°F) EWT (°F) TMBH SMBH LDB LWB GPM

(3)13 hp, (3)15 hp6-row DX coil36,000 cfw

R-22

75 62

75 1161 952 50.7 50.5 268

85 1114 931 51.3 51.0 267

95 1074 913 51.7 51.4 265

80 67

75 1255 941 56.0 55.8 292

85 1214 924 56.5 56.2 288

95 1169 906 59.9 56.6 286

85 72

75 1364 930 61.3 61.2 315

85 1319 913 61.7 61.5 310

95 1272 897 62.2 62.0 305

SWP 105E EDB (°F) EWB (°F) EWT (°F) TMBH SMBH LDB LWB GPM

(6)15 hp6-row DX coil36,000 cfm

R-22

75 62

75 1252 993 49.7 49.5 285

85 1191 965 50.4 50.1 284

95 1148 946 50.9 50.6 284

80 67

75 1344 976 55.1 54.9 312

85 1300 958 55.6 55.4 308

95 1253 939 56.1 55.8 305

85 72

75 1461 964 60.4 60.3 337

85 1413 947 60.9 60.7 332

95 1362 928 61.3 61.2 326



McQuay Cat 860-7 39

Performance Data

Waterside Economizer Capacity

Note: See Table 6 on page 31 to determine capacity at other than nominal cfm.

Table 9: SWP 018—6000 cfmEWT GPM EDB EWB TMBH SMBH LDB LWB LWT

45

33

75 62

120.1 118.4 57.0 55.1 52.3

43 136.0 128.6 55.4 54.2 51.4

72 163.5 142.7 53.3 52.5 49.5

39

80 67

164.7 135.9 59.3 58.4 53.4

51 187.4 145.3 57.8 57.1 52.4

85 225.2 160.8 55.5 54.9 50.3

55

20

75 62

61.1 61.1 65.7 58.6 61.2

26 74.2 74.2 63.7 57.8 60.7

46 92.7 92.7 60.9 56.8 59.0

26

80 67

93.2 93.2 65.8 62.3 62.1

34 106.0 105.9 63.9 61.6 61.2

59 126.2 120.0 61.7 60.5 59.3

Note: See Table 6 on page 31 to determine capacity at other than nominal cfm

Table 10: SWP 023—8000 cfmEWT GPM EDB EWB TMBH SMBH LDB LWB LWT

45

44

75 62

160.2 157.8 57.0 55.1 52.3

57 180.9 171.1 55.4 54.2 51.4

96 216.9 189.6 53.3 52.5 49.5

52

80 67

219.3 180.9 59.3 58.4 53.4

68 249.1 193.3 57.9 57.2 52.4

113 298.6 213.5 55.6 55.0 50.3

55

75 62

81.9 81.9 65.6 58.6 61.3

99.1 99.1 63.7 57.8 60.7

123.2 123.2 60.9 56.8 59.0

80 67

124.3 124.3 65.8 62.3 62.1

141.0 141.0 63.9 61.6 61.2

167.5 159.5 61.8 60.6 59.3


Table 11: SWP 028—10,000 cfmEWT GPM EDB EWB TMBH SMBH LDB LWB LWT

45

5575 62

199.9 196.6 57.0 55.2 52.371 224.4 212.3 55.6 54.3 51.3

120 266.5 234.2 53.6 52.7 49.465

80 67272.7 224.9 59.4 58.5 53.3

85 307.9 239.6 58.1 57.3 52.3142 366.1 263.5 55.9 55.2 50.2

55

3375 62

103.5 103.5 65.5 58.5 61.344 123.9 123.9 63.7 57.8 60.776 152.3 152.3 61.1 56.8 59.044

80 67155.4 155.4 65.8 62.3 62.1

57 175.1 175.1 64.0 61.7 61.198 206.1 197.1 62.0 60.7 59.2

40 McQuay Cat 860-7

Performance Data



45

65

75 62

259.8 249.5 56.0 54.6 52.9

85 289.9 266.5 54.7 53.6 51.8

144 338.3 290.5 52.9 52.1 49.7

79

80 67

357.0 283.0 58.4 57.7 54.1

101 399.8 300.7 57.1 56.4 52.9

170 466.0 327.9 55.0 54.4 50.5

55

39

75 62

137.0 137.0 64.6 58.2 62.0

52 160.6 160.6 62.8 57.5 61.1

92 192.2 192.2 60.4 56.6 59.2

52

80 67

201.8 201.8 64.6 61.9 62.7

69 223.9 221.9 63.1 61.3 61.5

118 261.2 244.3 61.4 60.3 59.4



45

76

75 62

303.4 291.4 56.0 54.6 53.0

99 339.0 311.5 54.7 53.6 51.8

168 396.3 339.9 52.8 52.1 49.7

92

80 67

417.3 330.7 58.4 57.6 54.1

118 467.6 351.4 57.0 56.4 52.9

198 545.9 383.6 54.9 54.4 50.5

55

46

75 62

159.6 159.6 64.6 58.2 62.0

61 187.4 187.4 62.8 57.5 61.1

107 224.9 224.9 60.3 56.6 59.2

61

80 67

235.6 235.6 64.6 61.9 62.7

80 261.7 259.3 63.1 61.3 61.5

137 305.9 285.7 61.3 60.3 59.5


45

87

75 62

369.9 345.7 55.2 54.0 53.5

113 406.0 365.0 54.1 53.2 52.2

192 463.6 393.1 52.5 51.8 49.8

105

80 67

506.7 389.7 57.7 57.0 54.7

135 556.3 410.2 56.6 55.9 53.2

227 639.3 444.4 54.6 54.0 50.6

55

52

75 62

199.7 199.7 63.6 57.8 62.6

70 227.3 227.3 62.0 57.2 61.5

122 262.5 262.5 60.0 56.4 59.3

70

80 67

284.9 284.4 63.7 61.6 63.2

92 312.9 305.0 62.6 61.0 61.8

157 357.7 330.0 61.1 60.1 59.6


McQuay Cat 860-7 41

Performance Data




45

109

75 62

458.8 429.4 55.4 54.1 53.4

142 501.9 452.5 54.3 53.3 52.1

240 571.5 486.7 52.7 52.0 49.8

131

80 67

626.8 483.6 57.9 57.1 54.6

169 684.6 507.6 56.8 56.1 53.1

283 787.5 549.9 54.9 54.2 50.6

55

65

75 62

249.4 249.4 63.6 57.8 62.6

87 282.4 282.4 62.1 57.2 61.5

153 324.7 324.7 60.2 56.5 59.3

87

80 67

353.9 353.3 63.8 61.6 63.1

115 387.3 378.2 62.7 61.1 61.8

196 441.0 408.9 61.3 60.2 59.5


45

109

75 62

547.3 512.8 55.5 54.1 53.4

142 622.8 552.3 53.9 53.0 51.3

240 678.9 580.2 52.9 52.1 49.7

131

80 67

746.3 577.2 58.0 57.2 54.5

169 852.0 620.9 56.3 55.6 52.2

283 935.1 655.0 55.0 54.4 50.5

55

65

75 62

298.9 298.9 63.6 57.8 62.6

87 354.8 354.8 61.5 57.0 60.8

153 386.5 386.5 60.3 56.5 59.2

87

80 67

422.5 421.9 63.9 61.6 63.1

115 481.0 463.7 62.3 60.9 61.0

196 524.1 487.5 61.4 60.3 59.5


45

131

75 62

571.2 527.2 54.9 53.8 53.7

170 622.7 554.2 53.9 53.0 52.3

288 708.2 595.5 52.3 51.6 49.9

157

80 67

781.7 593.5 57.4 56.7 55.0

203 852.3 622.7 56.3 55.6 53.4

290 927.2 653.6 55.1 54.5 51.4

55

79

75 62

310.9 310.9 63.2 57.6 62.9

105 349.6 349.6 61.7 57.1 61.7

183 398.4 398.4 59.8 56.4 59.4

105

80 67

439.3 435.8 63.4 61.4 63.4

137 479.6 463.6 62.3 60.9 62.0

235 544.6 498.9 61.0 60.0 59.6


42 McQuay Cat 860-7

Performance Data





45

153

75 62

675.1 618.5 54.8 53.7 53.8

198 729.7 647.0 53.9 52.9 52.4

336 822.8 692.2 52.4 51.7 49.9

183

80 67

919.2 694.3 57.3 56.6 55.0

237 997.6 726.7 56.3 55.6 53.4

286 1036.5 742.8 55.7 55.1 52.2

55

92

75 62

371.9 371.9 62.9 57.5 63.1

122 412.6 412.6 61.5 57.0 61.8

214 464.2 464.2 59.8 56.4 59.3

122

80 67

519.5 512.7 63.3 61.3 63.5

160 562.4 541.6 62.3 60.9 62.0

275 634.7 580.6 61.0 60.0 59.6


45

174

75 62

778.0 709.1 54.7 53.6 53.9

227 836.6 739.7 53.9 52.9 52.4

325 897.2 769.7 53.0 52.2 50.5

209

80 67

1190.6 791.2 57.4 56.6 55.0

270 1129.4 825.2 56.4 55.7 53.4

325 1183.7 847.6 55.8 55.1 52.3

55

105

75 62

432.5 432.5 62.6 57.4 63.3

140 475.0 475.0 61.4 57.0 61.8

244 530.1 530.1 59.9 56.4 59.3

140

80 67

599.1 588.8 63.2 61.3 63.6

183 644.8 619.2 62.3 60.8 62.0

314 725.0 662.4 61.1 60.0 59.6


45

196

75 62

876.0 798.3 54.7 53.6 53.9

255 942.2 832.8 53.8 52.9 52.4

400 1028.4 875.1 52.8 52.0 50.1

285

80 67

1250.0 920.0 56.6 55.9 53.8

300 1267.8 927.3 56.4 55.7 53.5

400 1363.5 966.8 55.4 54.8 51.8

55

118

75 62

486.8 486.8 62.6 57.4 63.3

157 534.8 534.8 61.4 57.0 61.8

275 596.9 596.9 59.8 56.4 59.3

157

80 67

674.5 662.9 63.2 61.3 63.6

206 726.2 697.1 62.3 60.8 62.0

353 816.6 745.8 61.1 60.0 59.6

McQuay Cat 860-7 43

Performance Data

Heating Capacity DataHot Water Coil Capacity (1-row)

Note: For complete one-row capacity and extended two-row capacity, contact your McQuay sales representative.Selections based on water, for glycol/water solutions, contact your McQuay sales representative.

Electric Heat

Table 21: Entering Water 180°F and Entering Air 60°F Unit cfm TMBH LWT LDB GPM

0184000 191.6 158.1 103.8 18

7000 241.7 152.4 91.6 18

0236000 277.9 158.8 102.4 25

9000 329.7 154.9 93.5 25

0288000 353.3 159.8 100.4 35

10500 397.1 157.5 94.6 35

0359000 430.2 158.1 103.7 40

13500 512.3 154.0 94.7 40

04011000 524.5 158.2 103.6 50

16000 621.0 155.2 95.5 50

04512000 579.0 157.9 104.1 55

18000 691.0 153.7 95.1 55

05516000 723.7 159.3 101.4 70

21000 815.9 156.9 95.5 70

06518000 808.6 159.5 101.1 75

24000 904.4 155.9 94.5 75

07018000 870.0 157.9 104.2 80

27500 1050.3 153.8 94.9 80

08020000 968.1 157.9 104.3 90

30000 1157.1 153.5 95.3 90

09524000 1123.7 158.6 102.8 105

34000 1300.9 155.1 95.5 105

10526000 1213.2 158.7 102.7 115

37000 1419.9 155.4 95.1 115

Table 22: Electric HeatSWP 208 V /60 Hz/ 3 PH 230 V/60 Hz/3 PH 400 V/50 Hz/3 PH 460 V/60 Hz/3 PH 575 V/60 Hz/3 PH

Unit size kW MBh FLA kW MBh FLA kW MBh FLA kW MBh FLA kW MBh FLA

018 to 040 27.8 94 77.2 34 116 85.6 25.7 88 37.2 34 116 42.8 34 116 34.2

045 to 105 55.6 190 154.4 68 232 170.9 51.4 175 74.4 68 232 85.6 68 232 68.4

44 McQuay Cat 860-7

Performance Data

Component Pressure Drops

Table 23: Unit Air Pressure Drops (inches wg)

Unit cfm 4", 30% filter 4", 65% filter 4-row economizer

High capacity DX coil 1-row HW Discharge plenum

front/backDischarge

plenum side

SWP 018

4500 0.17 0.28 0.28 0.54 0.11 0.21 0.33

5000 0.20 0.32 0.34 0.63 0.13 0.26 0.41

5500 0.23 0.37 0.40 0.73 0.15 0.31 0.50

6000 0.27 0.41 0.46 0.84 0.17 0.37 0.59

6500 0.30 0.46 0.53 0.95 0.20 0.43 0.69

7000 0.33 0.51 0.60 1.07 0.22 0.50 0.80

SWP 023

6000 0.18 0.28 0.29 0.56 0.10 0.19 0.31

6500 0.20 0.32 0.34 0.63 0.11 0.23 0.36

7000 0.23 0.35 0.38 0.71 0.13 0.26 0.42

7500 0.25 0.39 0.43 0.79 0.15 0.30 0.48

8000 0.28 0.43 0.48 0.87 0.16 0.35 0.54

8500 0.30 0.47 0.53 0.96 0.18 0.39 0.62

9000 0.33 0.51 0.59 1.05 0.20 0.44 0.69

SWP 028

6000 0.14 0.24 0.23 0.45 0.08 0.19 0.31

7000 0.18 0.30 0.30 0.57 0.10 0.26 0.42

8000 0.22 0.35 0.38 0.70 0.12 0.35 0.54

9000 0.27 0.41 0.46 0.84 0.15 0.44 0.69

10000 0.31 0.48 0.55 0.99 0.18 0.54 0.85

10500 0.34 0.51 0.65 1.07 0.20 0.59 0.94

SWP 035

9000 0.17 0.29 0.29 0.55 0.09 0.19 0.30

10000 0.21 0.33 0.34 0.64 0.11 0.23 0.37

11000 0.24 0.37 0.41 0.75 0.13 0.28 0.45

12000 0.27 0.42 0.49 0.86 0.16 0.33 0.53

13000 0.31 0.47 0.57 0.93 0.19 0.39 0.63

14000 0.34 0.52 0.67 1.05 0.22 0.45 0.73

SWP 040

11000 0.18 0.30 0.30 0.57 0.09 0.28 0.45

12000 0.21 0.33 0.35 0.63 0.11 0.33 0.53

13000 0.24 0.37 0.41 0.71 0.13 0.39 0.63

14000 0.26 0.41 0.48 0.80 0.15 0.45 0.73

15000 0.29 0.45 0.55 0.86 0.17 0.51 0.83

16000 0.32 0.49 0.57 0.95 0.18 0.59 0.95

17000 0.36 0.54 0.64 1.09 0.20 0.66 1.07

SWP 045

12000 0.18 0.29 0.29 0.56 0.09 0.27 0.42

13500 0.21 0.34 0.36 0.67 0.11 0.34 0.54

15000 0.25 0.39 0.43 0.79 0.14 0.42 0.66

16500 0.29 0.45 0.50 0.92 0.16 0.51 0.80

18000 0.33 0.50 0.59 1.01 0.18 0.61 0.95

Notes: DX pressure drops are wet coil and economizer are dry coil.All units must have a DX coil pressure drop.Use “Side” pressure drop data with double discharge configurations of “Front and Side,” “Back and Side,” or “Two Sides.” For discharge configuration of “Front and Back,” contact your local McQuay Representative for information.

McQuay Cat 860-7 45

Performance Data

SWP 055

14000 0.18 0.29 0.29 0.55 0.10 0.22 0.34

15500 0.21 0.33 0.33 0.65 0.12 0.27 0.42

17000 0.24 0.37 0.39 0.75 0.14 0.32 0.50

18500 0.27 0.42 0.44 0.85 0.16 0.38 0.59

20000 0.30 0.47 0.53 0.96 0.18 0.45 0.69

21500 0.34 0.51 0.60 1.08 0.20 0.52 0.80

SWP 065

17000 0.16 0.30 0.34 0.64 0.12 0.32 0.50

18500 0.18 0.34 0.38 0.73 0.14 0.38 0.59

20000 0.21 0.38 0.46 0.82 0.15 0.45 0.69

21500 0.23 0.42 0.52 0.92 0.17 0.52 0.80

23000 0.26 0.47 0.59 1.03 0.19 0.61 0.94

24500 0.29 0.51 0.68 1.14 0.20 0.70 1.08

SWP 070

18000 0.18 0.29 0.29 0.55 0.10 0.34 0.53

20000 0.21 0.33 0.35 0.65 0.12 0.42 0.66

22000 0.24 0.38 0.41 0.76 0.14 0.51 0.80

24000 0.27 0.43 0.46 0.87 0.16 0.61 0.95

26000 0.31 0.47 0.52 0.98 0.19 0.71 1.11

28000 0.35 0.53 0.59 1.06 0.21 0.82 1.29

SWP 080

20000 0.18 0.29 0.29 0.56 0.10 0.30 0.47

22000 0.21 0.33 0.33 0.65 0.12 0.36 0.57

24000 0.24 0.37 0.39 0.74 0.14 0.43 0.68

26000 0.27 0.41 0.45 0.84 0.16 0.51 0.80

28000 0.30 0.46 0.50 0.95 0.18 0.59 0.92

30000 0.33 0.50 0.56 1.05 0.20 0.68 1.06

SWP 095

22000 0.18 0.29 0.29 0.56 0.10 0.36 0.57

24000 0.21 0.33 0.33 0.65 0.12 0.43 0.68

26000 0.23 0.37 0.39 0.73 0.14 0.51 0.80

28000 0.26 0.41 0.43 0.82 0.16 0.59 0.92

30000 0.29 0.45 0.49 0.92 0.18 0.68 1.06

32000 0.32 0.49 0.53 0.98 0.20 0.77 1.20

34000 0.35 0.53 0.59 1.11 0.22 0.87 1.36

SWP 105

26000 0.19 0.30 0.32 0.57 0.11 0.22 0.36

28000 0.21 0.34 0.36 0.64 0.13 0.26 0.42

30000 0.24 0.37 0.41 0.71 0.14 0.30 0.48

32000 0.27 0.41 0.46 0.79 0.16 0.34 0.54

34000 0.29 0.45 0.51 0.87 0.18 0.38 0.61

36000 0.32 0.48 0.56 0.97 0.19 0.43 0.68

38000 0.35 0.52 0.61 1.05 0.21 0.47 0.76

Table 23: Unit Air Pressure Drops (inches wg) (continued)

Unit cfm 4", 30% filter 4", 65% filter 4-row economizer

High capacity DX coil 1-row HW Discharge plenum

front/backDischarge

plenum side

Notes: DX pressure drops are wet coil and economizer are dry coil.All units must have a DX coil pressure drop.Use “Side” pressure drop data with double discharge configurations of “Front and Side,” “Back and Side,” or “Two Sides.” For discharge configuration of “Front and Back,” contact your local McQuay Representative for information.

46 McQuay Cat 860-7

Performance Data

Figure 16: Condenser Water Pressure Drop, SWP 018D to 040D, Independent Refrigerant Circuits

Figure 17: Condenser Water Pressure Drop, SWP 045D to 105E, Independent Refrigerant Circuits

Figure 18: Condenser Water Pressure Drop, SWP 018F to 095F, Dual Refrigerant Circuits

Figure 19: Economizer System Water Pressure Drop, SWP 018 to 105

3

4

6

8

40

20

10

20 40 60 80 200 300100Condenser flow rate (gpm)

Pre

sssu

re d

rop

(ftH

O)

2

18HP

24HP

28HP

32HP

36HP

40HP

Note: HP = Total unit compressor horsepower.Condenser flow rate (GPM)

100

Pre

ssur

e dr

op (f

t H20

)

10

40 H

P46

HP

52 H

P56

HP60

HP70

HP78

, 80,

84, 9

0 HP,

sizes

80, 9

5

78HP,

size 1

05

84 H

P, siz

e 105

90 H

P, siz

e 105

2

80 500

60

200 400

4

6

8

20

40

Note: HP = Total unit compressor horsepower.

Note: HP = Total unit compressor horsepower.

Condenser flow rate (gpm)

Pre

ssur

e dr

op (f

t H2O

)

60

10

40

20

6

8

4

210 100 500

24–3

2 HP

36–4

0 HP

46 H

P52

HP

56 H

P60

HP

80706050403020 150 200 250 300 400

Notes: Includes coil, Control valves, and interconnecting piping.Add this ΔP to condenser ΔP to obtain unit ΔP for pump selection.

10 100 500

1

10

50

018D

028D

035D

– 040D

045D

095D

105E

Condenser Flow Rate (gpm)

Pres

sure

Dro

p(ft

HO

)2

– –

McQuay Cat 860-7 47

Performance Data

Figure 20: Hot Water Coil Water Pressure Drop (1-row), SWP 018 to 040

Figure 21: Hot Water Coil Water Pressure Drop (1-row), SWP 045 to 105

Figure 22: Water Regulating Valve Pressure Drop

200

045D

040D

1

10

100

10 100

Water flow rate (GPM)

Pre

ssur

e dr

op (f

t. H

O)

2

018D

023D

–028

D

Water flow rate (gpm)10 100

Pre

ssur

e dr

op (f

t H2O

)

1

10

100

200

045D040D

–055

D

070D

–095

D

105E

40

10

1

0.110 100 500

Condenser flow rate (gpm)

Pre

ssur

e dr

op (f

t H2O

)

018-0

40D

045-0

95D

48 McQuay Cat 860-7

Performance Data

Fan CurvesFigure 23: SWP 018, 15" × 15" Forward Curved Fan

Figure 24: SWP 023/028, 18" × 18" Forward Curved Fan

Note: Do not select an operating point in the shaded areas.Fan TSP limit is 5.5" of water. Consult your local McQuay sales representative for applications beyond this range.


McQuay Cat 860-7 49

Performance Data


Figure 26: SWP 035/040, 20" Airfoil Fan


1800 rpm

6

5

4

3

2

1

00

Stat

ic p

ress

ure

(inch

es o

f wat

er)

1600 rpm

1400 rpm

1200 rpm

1000 rpm

800 rpm

50005000 10000 15000 2000020000

2000 rpm

2200 rpm

2400 rpm

2600 rpm

2800 rpm

25 hp

CFM

20 hp15 hp

10 hp7.5 hp

5 hp3 hp

2 hp1.5 hp1.0 hp


50 McQuay Cat 860-7

Performance Data

Figure 27: SWP 045, 22" × 22" Forward Curved Fan

Figure 28: SWP 045, 22" Airfoil Fan


1.0 hp

1.5 hp2.0 hp 3.0 hp

5.0 hp

7.5 hp

15000CFM

1000050000 20000 250000

1

2

3

4

5

6

Stat

ic p

ress

ure

(inch

es o

f wat

er)

10.0 hp

15 hp

20 hp

25 hp2600 rpm

2400 rpm

2200 rpm

2000 rpm

1800 rpm

1600 rpm

1200 rpm

1400 rpm

800 rpm

1000 rpm


McQuay Cat 860-7 51

Performance Data

Figure 29: SWP 055/065/070, 25" × 25" Forward Curved Fan

Figure 30: SWP 055/065/075, 25" Airfoil Fan


5.0 hp

7.5 hp10.0 hp

15 hp20 hp

25 hp

2600 rpm2400 rpm2200 rpm

2000 rpm

1800 rpm

00

1

2

3

4

5

Stat

ic p

ress

ure

(inch

es o

f wat

er)

6

15000CFM

100005000 20000 25000 30000

30 hp40 hp

1600 rpm

1200 rpm

1400 rpm

800 rpm

1000 rpm


52 McQuay Cat 860-7


Figure 32: SWP 080/090, 27" Airfoil Fan


7.5 hp10.0 hp

15 hp

20 hp

25 hp

2600 rpm

2400 rpm

2200 rpm

1600 rpm

2000 rpm

1800 rpm

15000CFM

100005000 20000 25000 30000

30 hp

40 hp

00

1

2

3

4

5

Stat

ic p

ress

ure

(inch

es o

f wat

er)

6

35000 40000

1200 rpm

1400 rpm

400 rpm

1000 rpm

800 rpm

600 rpm


McQuay Cat 860-7 53

Performance Data

Figure 33: SWP 105, 33" Airfoil Fan

CFM

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

2.0

3.0

5.0

7.5

10.0 15.0

20.0

25.0

30.0

40.0

50.0

HP

1.5

1300

1400

RPM

0 4000 8000 12000 16000 20000 24000 28000 32000 36000 40000

Sta

ticP

ress

ure

(inch

es

ofw

ate

r)1100 RPM

1200

900

1000

800

700

600

500

400


54 McQuay Cat 860-7

Dimensional Data

Dimensional DataFigure 34: Left Side, Front (CW) Discharge Figure 35: Left Side, Back (CCW) Discharge

A

K x L return air

Filte

r sec

tion

Eco

nom

izer

Eva

pora

tor

Hea

ter

Ele

ctric

al p

anel

G J

Multi-directional plenum, optional

(Plenun can ship separately.All openings are on the

plenum centerline.For additional information,

see submittal drawings.)

3.25"

Outlet

Inlet

Q R

19.0"(20.33 for 105E)

Note: Fan outlet dimensions are for FC fans. AF fan outlet dimensions are similar. For exact AF outlet dimensions, consult your local McQuay representative.

A

K x L return air

Filte

r sec

tion

Eco

nom

izer

Evap

orat

or

Hea

ter

Ele

ctric

al p

anel

3.25"

Outlet

Inlet

9.63"(18-95)10.31(105)

Multi-directional plenum, optional

(Plenun can ship separately.All openings are on the

plenum centerline.For additional information,

see submittal drawings.)

19.0"(20.33 for 105E)

Q R

Note: Fan outlet dimensions are for FC fans. AF fan outlet dimensions are similar. For exact AF outlet dimensions, consult your local McQuay representative.

Table 24: DimensionsBasic unit 018 023 028 035 040 045 055 065 070 080 095 105

A Deptha b 72.00 72.00 72.00 72.00 72.00 81.00 81.00 81.0 81.00 84.00 84.00 96.00

B Lengtha b 84.00 84.00 84.00 100.00 100.00 120.00 120.00 120.0 132.00 144.00 156.00 156.00

D Heighta b 82.00 82.00 82.00 82.00 82.00 82.00 82.00 88.0 88.00 88.00 88.00 96.00

F Fan discharge 18.62 21.88 21.88 24.75 24.75 27.25 31.25 31.25 31.25 34.25 34.25 47.25

G Fan discharge ⊥ to shaft 15.88 18.88 18.88 24.75 24.75 27.25 31.25 31.25 31.25 34.25 34.25 34.94

H Fan discharge location 32.69 31.06 31.06 37.62 37.62 46.38 44.38 44.38 50.38 54.88 60.88 54.40

J Fan discharge location 22.50 18.81 18.81 20.12 20.12 21.06 21.32 21.32 21.32 23.82 23.82 33.76

K Return opening height 41.44 41.44 41.44 51.44 51.44 51.44 51.44 62.20 62.20 62.20 62.20 70.20

L Return opening length 80.00 80.00 80.00 96.00 96.00 116.00 116.00 116.00 128.00 140.00 152.00 152.00

M Base of return opening 28.62 28.62 28.62 28.62 28.62 28.62 28.62 23.87 23.87 23.87 23.87 23.87

N Water out/in (ODS) 2 1/8 2 1/8 2 1/8 2 5/8 2 5/8 2 5/8 3 1/8 3 1/8 3 1/8 3 1/8 3 1/8 3 1/8

P 1-row HW connection (ODS) 1 5/8 1 5/8 1 5/8 1 5/8 1 5/8 1 5/8 1 5/8 1 5/8 2 1/8 2 1/8 2 1/8 2 1/8

P 2-row HW connection (ODS) 1 5/8 1 5/8 1 5/8 1 5/8 1 5/8 2 1/8 2 1/8 2 1/8 2 1/8 — — —

Q Condenser outlet 16.5 16.5 16.5 16.5 16.5 16.5 16.8 16.8 16.8 16.8 16.8 17.76

R Condenser inlet 10.5 10.5 10.5 10.5 10.5 10.5 10.8 10.8 10.8 10.8 10.8 11.75a. Dimensions do not include lifting lugs, handle, latch, or fastener extensions.b. For shipping dimensions, add 4" (102 mm) to depth, 8" (204 mm) to length, and 4" (102 mm) to height.

McQuay Cat 860-7 55

Dimensional Data

Figure 36: Unit Front Plan

Figure 37: Front Elevation

Left SideLeft SidePiping ConnectionsPiping Connections

(See Notes)(See Notes)

(Optional)(Optional)Right SideRight SidePiping ConnectionsPiping Connections(See Notes)(See Notes)

SupplySupplyFan MotorFan Motor

Return AirReturn Air

PowerPowerEntryEntry

3-1/8"3-1/8"

Note: Service connections determined when facing the front of the unit. Left-hand standard, right-hand optional. Please indicate on the unit submittal.

Disconnectswitch (optional) MicroTech II panel

AFD (optional)

Electricalaccess

Mechanicalaccess

D

B

76"

Power entry7/8" pilot K.O.

Notes: Unit sizes 018, 023, and 028 have a single mechanical access panel.

56 McQuay Cat 860-7

Figure 38: Back Elevation

Figure 39: Left Side (typical)

M

2.0"

2.0" Typical

H HF

29"

D

B

K × LReturn air opening

Mechanical access

(optional)

Multi-directionalplenum*

1" Neoprene isolation pads,shipped separately

Notes: Service connections determined when facing the front of the unit. Left-hand standard, right-hand optional. Please indicate on the unit submittal. Unit sizes 018, 023, and 028 have a single mechanical access panel.

*

* Select unit arrangement on the unit selection. Plenum can ship separately. All openings are on plenum center line. For additonal information, refer to submittal drawing.

Lifting lug1" typ. A/2

38.5"(N) Water in

(N) Water out1 1/8" ODS drain

K × L return air

(optional)

Multi-directionalplenum*

A

44.5"

(P) Hot water in

(P) Hot water out

Notes: Service connections determined when facing the front of the unit. Left-hand standard, right-hand optional. Please indicate on the unit submittal.

* Select unit arrangement on the unit selection. Plenum can ship separately. All openings are on plenum center line. For additonal information, refer to submittal drawing.

McQuay Cat 860-7 57

Dimensional Data

Figure 40: Type SWP Plenum (typical)

Recommended ClearancesFor good installation, service, and maintenance access, follow the recommended clearances below. Minimum clearances required by local, state, or federal codes, such as the NEC, take precedence over those listed below. Clearance is required to allow room for side filter access, mechanical cleaning of condenser tubes, economizer coil access to expansion valves and other control components, and to allow for possible fan shaft or compressor removal.

Note – For clearance requirements less than those indicated, consult your local McQuay sales representative

Figure 41: Recommended Service and Maintenance Clearances

Note: If water and condensate drain are left hand, 36 inches is required.

Table 25: Discharge Plenum Duct Openings

Unit size A—front/back available lengths (in) B—left/right available lengths (in) H—heights of available duct openings (in)

018 to 028 24 30 36 42 48 54 60 66 — — — — — 24 30 36 42 48 54 — — 12 15 18 21 24

035 to 040 24 30 36 42 48 54 60 66 72 78 — — — 24 30 36 42 48 54 — — 12 15 18 21 24

045 to 070 — 30 36 42 48 54 60 66 72 78 84 90 96 — 30 36 42 48 54 60 — 12 15 18 21 24

080 to 105 — 30 36 42 48 54 60 66 72 78 84 90 96 — 30 36 42 48 54 60 66 12 15 18 21 24

HeightHeight

Unit size Length (in) Depth (in) Height (in)

018 to 028 84 72 23,29,35,41

035 to 040 100 72 23,29,35,41

045 to 065 120 81 29,35,41

070 132 81 29,35,41

080 144 84 29,35,41

095 to 105 156 84 29,35,41

Note: Standard plenum height is 29”. Consult your local McQuay Sales representative for details.

Unit front 42 inchUnit rear 24 inchMotor location side 36 inchPiping location side 36 inchSide without motor or piping 24 inch

VFD

See note.1 3 5 246

42"

24"or

36"36"

Airflow

EvaporatorCoil

MotorCompressor

24"

58 McQuay Cat 860-7

Electrical Data

Electrical Data

Table 26: SAF Motor Nameplate Amperage

Horsepower Type208/60/3 230/60/3 400/50/3a

a. 460/60/3 motors are used. Derate nameplate horsepower to 0.83 to obtain actual horsepower.

460/60/3 575/60/3

FLA FLA FLA FLA FLA

3High efficiency 9.9 9.0 4.5 4.5 3.4

Premium efficiency 9.3 8.2 4.1 4.1 3.1

5High efficiency 16.1 14.0 7.0 7.0 5.3


7.5High efficiency 25.0 21.6 10.8 10.8 8.2


10High efficiency 33.0 28.0 14.0 14.0 11.0


15High efficiency 44.8 40.6 20.3 20.3 16.2


20High efficiency 61.0 50.0 25.0 25.0 20.0


25High efficiency 74.0 62.0 31.0 31.0 24.3


30High efficiency 86.5 75.0 37.5 37.5 30.0


40High efficiency 117.0 102.0 51.0 51.0 40.0


50High efficiency 140.0 124.0 62.0 62.0 49.2


60High efficiency 154.0 144.0 72.0 72.0 57.4


McQuay Cat 860-7 59

Table 27: R-22 and R-407C Compressor Amperages

Compressor hp Refrigerant208/60/3 230/60/3 460/60/3 575/60/3

RLA LRA RLA LRA RLA LRA RLA LRA

6R-22 16.5 156 14.9 156 7.4 75 6.0 54

R-407 16.3 156 14.7 156 7.3 75 5.8 54

7R-22 19.5 164 17.6 164 9.6 100 7.7 78

R-407 — — — — — — — —

8R-22 24.4 189 22.1 189 11.0 99 8.8 74

R-407 — — — — — — — —

9R-22 27.4 232 24.8 232 12.4 125 9.9 100

R-407 — — — — — — — —

10R-22 31.4 278 28.4 278 14.2 127 11.4 100

R-407 30.4 278 27.5 278 13.8 127 11.0 100

13R-22 35.5 350 32.1 350 16.0 158 13.1 125

R-407 35.9 350 32.5 350 16.2 158 13.0 125

15R-22 44.3 425 40.1 425 20.0 187 16.0 148

R-407 43.3 425 39.6 425 19.8 187 15.8 148

20R-22 72.3 415 65.4 360 32.7 180 26.2 144

R-407 72.3 415 65.4 425 32.7 187 — —

Table 28: Electric Heat

SWP unit size208 V/60 Hz/3 PH 230 V/60 HZ/3 PH 400 V/50 Hz/3 PH 460 V/60 Hz/3 PH 575 V/60 Hz/3 PH

kW MBh FLA kW MBh FLA kW MBh FLA kW MBh FLA kW MBh FLA

018 to 040 27.8 94 77.2 34 116 85.6 25.7 88 37.2 34 116 42.8 34 116 34.2

045 to 105 55.6 190 154.4 68 232 170.9 51.4 175 74.4 68 232 85.6 68 232 68.4

60 McQuay Cat 860-7

Electrical Data

Supply Power Wiring1 Units require three-phase power supply.2 Allowable voltage tolerances:

a 60 Hertz Nameplate 208 V: Min. 187 V, Max. 229 VNameplate 230 V: Min. 207 V, Max. 253 VNameplate 460 V: Min. 414 V, Max. 506 VNameplate 575 V: Min. 518 V, Max. 632 V

b 50 HertzNameplate 400 V: Min. 342 V, Max. 418 V

3 Power lead wire sizing:a For units with cooling capability (all concurrent loads)

with or without hot water heating and circuits with motor loads only:MCA = 1.25 (largest motor RLA or LA) + other loads +

2 ampsb For units with cooling capability and non concurrent

electric heat capability:In the cooling mode, the loads are composed of supply fan motor and compressors. In heating mode, the loads are composed of supply fan motor and electric heater. The MCA is calculated for unit running in either mode; the highest value obtained is used for the MCA.

For unit in cooling mode:MCA = 1.25 (largest RLA or FLA) + other loads + 2 amps

For unit in heating mode:MCA = 1.25 (electric heat FLA + supply fan motor FLA) + 2 amps

4 Size wires in accordance with Table 310-16 or 310-19 of the National Electrical Code.Note– Use copper wire only.

5 Size wires for a maximum of 3% voltage drop.

Lug Sizes

Note: Use copper wire only.

Table 29: Lug Sizes for Single DisconnectDIsconnect size (amps) Lug size

100 #12-3/0150 #12-3/0250 #8-350 MCM400 (2) #8-600 MCM600 (2) #8-600 MCM

Table 30: Lug Sizes for Power BlockPower block size (amps) Lug size

310 #6-350 MCM420 #2-600 MCM570 (2) #4-300 MCM760 (2) #6-500 MCM

McQuay Cat 860-7 61

Unit Weights

Table 31: Unit and Component Weight (lbs)

Unit weightsUnit size

018 023 028 035 040 045 055 065 070 080 095 105Basic configuration

SWP basic unita

a. Base weight includes supply fan without motor. Add about 100 lbs. for airfoil fans.

2226 2313 2318 2638 2643 3110 3279 3406 3734 4021 4246 4766Filters

4" 30% or 65% efficiency 38 38 38 55 55 66 66 79 87 96 104 112Evaporator coil6 row, 12 fpi 250 294 321 417 468 506 577 642 693 755 819 926Evaporator coilWater economizer coilb c

b. Water economizer weight includes valves and piping.c. The values in this table do not include water weight.

4-row, 12 fpi 306 338 357 458 493 520 598 648 678 723 820 927Water weight 51 66 75 94 111 119 150 168 187 203 218 290

Hot water coild c

1-row, 12 fpi 71 97 114 130 158 160 170 200 328 337 345 371Water weight 16 20 23 28 32 37 41 49 55 59 62 62Electric heat

34 kW 20 20 20 20 20 — — — — — — —68 kW — — — — — 40 40 40 40 40 40 40

Supply fan motors3 hp ODP 71 — — — — — — — — — — —5 hp ODP 82 — — — — — — — — — — —

7.5 hp ODP 124 124 — — — — — — — — — —10 hp ODP 144 144 144 144 — — — — — — — —15 hp ODP — 185 185 185 185 185 — — — — — —20 hp ODP — — 214 214 214 214 214 214 214 — — —25 hp ODP — — — — 266 266 266 266 266 266 — —30 hp ODP — — — — — 310 310 310 310 310 310 31040 hp ODP — — — — — — 404 404 404 404 404 40450 hp ODP — — — — — — — — — 452 452 45260 hp ODP — — — — — — — — — — 620 6203 hp TEFC 72 — — — — — — — — — — —5 hp TEFC 85 — — — — — — — — — — —

7.5 hp TEFC 140 140 — — — — — — — — — —10 hp TEFC 170 170 170 170 — — — — — — — —15 hp TEFC — 235 235 235 235 235 — — — — — —20 hp TEFC — — 300 300 300 300 300 300 300 — — —25 hp TEFC — — — — 330 330 330 330 330 330 — —30 hp TEFC — — — — — 390 390 390 390 390 390 39040 hp TEFC — — — — — — 510 510 510 510 510 51050 hp TEFC — — — — — — — — — 570 570 57060 hp TEFC — — — — — — — — — — 850 850

Discharge plenum23” high 551 551 551 616 616 — — — — — — —29” High 636 636 636 711 711 862 862 862 922 1003 1064 106435” high 719 719 719 804 804 975 975 975 1042 1134 1203 120341” high 805 805 805 899 899 1090 1090 1090 1166 1269 1346 1346

62 McQuay Cat 860-7

Unit Weights

Table 32: Compressor/Condenser Weight (lbs)

Compressor/condenser assembly Water

Unit size

018 023 028 035 040 045 055 065 070 080 095 105

(3) 6 hp 35 538 538 — — — — — — — — — —

(4) 6 hp 43 777 777 777 — — — — — — — — —

(4) 7 hp 57 — 786 786 786 786 — — — — — — —

(4) 8 hp 66 — — 1215 1215 1215 — — — — — — —

(4) 9 hp 74 — — — 1272 1272 — — — — — — —

(4) 10 hp 95 — — — 1287 1287 1287 — — — — — —

(2) 10 hp, (2) 13hp 106 — — — — — 1376 1376 — — — — —

(4) 13 hp 118 — — — — — 1464 1464 1464 1464 1464 1464 1464

(2) 13 hp, (2) 15h p 129 — — — — — 1575 1575 1575 1575 1575 1575 1575

(4) 15 hp 141 — — — — — — 1684 1684 1684 1684 1684 1684

(2) 15 hp, (2) 20 hp 152 — — — — — — — — 1982 1982 1982 1982

(4) 20 hp 190 — — — — — — — — — — — 2096

(6) 13 hp 167 — — — — — — — — — 2096 2010 2010

(3) 13 hp, (3) 15 hp 178 — — — — — — — — — 2135 2135 2135

(6) 15 hp 188 — — — — — — — — — 2260 2260 2260

(3) 15 hp, (3) 20 hp 209 — — — — — — — — — — — 2419

Table 33: Variable Frequency Drive Weight (lbs)

VoltageVariable frequency drive size (hp)

3 5 7.5 10 15 20 25 30 40 50 60

208/230V 25 25 40 50 50 75 75 100 100 — —

380/460V 20 20 25 25 40 50 50 75 75 75 100

McQuay Cat 860-7 63

Engineering Guide Specifications

Engineering Guide SpecificationsGeneral

Furnish and install, as shown on plans, McQuay model SWP self-contained packaged air conditioning system(s). Unit performance, electrical characteristics and unit arrangement shall be per the job schedule.

Each unit shall be completely factory assembled and shipped in one piece. [A custom, factory built acoustic discharge plenum shall be shipped mounted and secured to the base unit.] [A custom, factory built acoustic discharge plenum shall be shipped with the unit for field installation.] All units shall be shipped fully charged with Refrigerant 22 and oil. Unit ratings shall be in accordance with the latest update of ARI Standard 360.

All units shall have decals and tags to indicate caution areas and to aid in unit service. A unit nameplate shall be fixed to a permanent panel next to the main control panel access. Electrical wiring diagrams shall be supplied with each unit. Installation, operating and maintenance bulletins and start-up forms shall be supplied with each unit.

Factory run test

Each unit shall undergo a rigorous factory run test prior to shipment and factory test sheets shall be available upon request. The factory test shall include dynamic trim balancing of the completed fan assembly, a compressor run check, a complete run test of all electrical components and safeties, including proper control sequencing, a leak check of all refrigerant circuits, a leak check of all water circuits and a final unit inspection.

Safety Agency Listed

The complete unit(s) shall be ETL-US and ETL-Canada listed by Intertek Testing Services, Inc. Units shall conform to bi-national standard ANSI/UL Standard 1995/CSA Standard C22.2 No. 236. Unit(s) shall be accepted for use in the City of New York by the Department of Building, MEA #368-93-E Vol. II.

Cabinet, Casing and Frame

Each unit shall have a welded 3/16" structural steel base integrated with formed members of 10, 12, and 14 gauge continuous galvanized steel. Exterior frame and panels shall be constructed of pre-painted galvanized steel for aesthetics and long term durability. Paint finish to include a base primer with a high quality, polyester resin topcoat of a neutral beige color. Finished surface to withstand a minimum 750-hour salt spray test in accordance with ASTM B117 standard for salt spray resistance. Lifting brackets capable of handling the unit

shipping weight shall be welded to the unit base with holes to accept cable or chain hooks.

Each unit shall be compartmentalized for ease of service and shall be designed to permit adjustment of system electrical and refrigeration components while the unit is in operation. The unit shall incorporate removable access panels tightly set on neoprene gaskets. Access panels shall be a minimum of 18-gauge galvanized steel and shall be located on all sides of the unit for complete accessibility. The airside cabinet shall be insulated with 1", 1.5 pound density coated glass fiber insulation. [Solid galvanized steel liners shall be provided, allowing no exposed insulation within the air stream.]

Filters

Each unit shall be provided with an integral filter section complete with 4" panel filters. The filters shall be removable from the rear of the unit and shall have side access capability through [access panels] [hinged and latched access doors] on each end of the unit. The use of 2" filters is not acceptable.

[4" thick, 30% efficient, UL Std. 900, Class II, AmericanAirFilter filters shall be provided. Filters shall be frame mounted and shall slide into galvanized steel tracks contained within the unit.]

[4" thick, 60-65% efficient, UL Std. 900, Class II, AmericanAirFilter Varicel filters shall be provided. Filters shall be frame mounted and shall slide into galvanized steel tracks contained within the unit.] [An auxiliary pre-filter rack, with 4" thick 30% efficient filters, shall be provided upstream of the high efficiency filters.]

[4" thick, 80-85% efficient, UL Std. 900, Class II, AmericanAirFilter Varicel filters shall be provided. Filters shall be frame mounted and shall slide into galvanized steel tracks contained within the unit.] [An auxiliary pre-filter rack, with 4" thick 30% efficient filters, shall be provided upstream of the high efficiency filters.]

Economizer

Waterside economizer

A complete waterside economizer package shall be provided including a mechanically cleanable [chemically cleanable] coil, control valves and factory piping complete with cleanouts. Coils shall be fabricated of seamless 1/2" diameter copper tubing that is mechanically expanded into high efficiency aluminum plate fins. Coils shall be a minimum 4-row, staggered tube design with 12 fins per inch. The coil shall be mounted in the main unit drain pan. Access panels shall provide convenient access to the coil, valves and drain-pan for inspection and cleaning. The complete economizer package shall be rated for [400 psig (size 018 to 095)] [200 psig (size 105)] waterside working pressure.

64 McQuay Cat 860-7


Economizer operation shall be controlled to maximize free cooling. Economizer operation shall be enabled whenever the entering water temperature is less than the entering air temperature by a field adjustable value. The economizer control valve shall modulate in response to the cooling load. Control valve operation shall [maintain full flow through the unit at all times.] [isolate the unit from the condenser water loop when there is no call for cooling, allowing for the use of an energy saving, variable pumping system.]

Mechanical cooling shall be enabled during economizer operation. If the economizer control valve is driven 90% open and the cooling load is not satisfied, compressors will stage on to maintain set point. To maximize energy savings, economizer control will maintain full water flow until the differential between entering water and entering air temperatures falls below set point.

A factory installed, non-averaging type freezestat shall provide some protection against coil freeze-up.

The completed economizer assembly shall be factory leak tested.

Airside economizer control (external mixing box)

Integrated airside economizer control capability of a separate unit or remote mounted mixing box shall be provided. Economizer operation shall be controlled to maximize free cooling operation. Economizer shall be enabled whenever the remote [outside air enthalpy sensor] [comparative enthalpy sensors] [outside air temperature sensor] indicates that outside air is suitable for free cooling. The remote economizer damper actuator shall modulate in response to the cooling load.

Mechanical cooling shall be enabled during economizer operation. If the outside air damper is driven to 90% open and the cooling load is not satisfied, compressors will stage on to maintain set point. To maximize energy savings, the economizer control will maintain 100% outdoor airflow until disabled by the enthalpy or temperature cutout. Outside air will reset to minimum position at that time.

Supply Fan

Fan assembly

All fan assemblies shall be statically and dynamically balanced at the factory, including a final trim balance, prior to shipment. All fan assemblies shall employ solid steel fan shafts. Heavy-duty pillow block type, self-aligning, grease lubricated ball bearings shall be used. Bearings shall be sized to provide an L-50 life at 200,000 hours and shall be no smaller than the main shaft diameter. The entire fan, drive and motor assembly shall be mounted on a welded, heavy-gauge tubular steel frame and shall be mounted on [spring isolators] [spring isolators with seismic restraints]. The fan assembly shall further be isolated from the unit with a flexible connection at the fan discharge. Fixed pitch V-belt drives with matching belts shall be provided. V-belt drives shall be selected at [the manufacturer’s standard service factor] [1.5 times fan brake horsepower].

Forward curved fans (SWP 018 to 095)

The supply air fan shall be a double width, double inlet (DWDI) forward curved centrifugal fan, with hub and shaft secured with mating keyways. The fan wheel and housing shall be constructed from painted steel and shall be Class II construction to satisfy the specified application.

The fan assembly shall feature a gradual expansion, aerodynamic duct outlet to reduce system sound generation.

Air foil fans (SWP 035 to 105)

The supply air fan shall be a double width, double inlet (DWDI) airfoil centrifugal fan, with hub and shaft secured with mating keyways. The fan wheel housing shall be constructed of painted steel and shall be Class II construction to satisfy the specified application.

Fan motor

Fan motors shall be heavy-duty 1800 rpm [open drip-proof (ODP)] [totally enclosed fan cooled (TEFC)] type with grease lubricated ball bearings. [Motors shall be high efficiency and meet applicable EPACT requirements.] [Motors shall be premium efficiency.] Motors shall be NEMA, T-frame, Class B. Motors shall be mounted on an adjustable base that provides for proper alignment and belt tension adjustment.

Variable frequency drives (SWP 018 to 105E)

An electronic variable frequency drive shall be provided for the supply air fan. Variable frequency drives shall be latest generation pulse width modulation type utilizing IGBT technology. The drive shall be factory installed in a designated location that provides ready access to the drive and does not void unit accessibility. Drives shall meet UL Standard 95-5V and the variable frequency drive manufacturer shall have specifically approved them for plenum duty application. The completed unit assembly shall be listed by a recognized safety agency, such as ETL.

McQuay Cat 860-7 65


The unit manufacturer shall install all power and control wiring. [A manually activated bypass contactor arrangement shall be provided. The bypass arrangement will allow fan operation at full design cfm, even if the drive has been removed for service.]

The supply air fan drive output shall be controlled by the factory installed main unit control system and drive status and operating speed shall be monitored and displayed at the main unit control panel. A factory mounted, field adjustable duct high-limit control shall be provided to protect ductwork from excessive duct pressure. The installer shall provide and install sensor tubing from [a single unit mounted pressure sensor] [two unit mounted pressure sensors] to the duct location(s).

All drives shall be factory run tested prior to unit shipment.

Cooling Coil

Drain pan

The coil section shall be complete with an insulated stainless steel drain pan. The drain pan shall be sloped in two directions to provide positive drainage. Access panels on both sides of the unit shall provide convenient access to the coil and drain pan for inspection and cleaning. A factory-installed drain line, with trap and cleanout, shall be provided for convenient connection at the unit exterior.

Cooling coil

Direct expansion (DX) cooling coils shall be fabricated of seamless 1/2" diameter high efficiency copper tubing that is mechanically expanded into high efficiency aluminum plate fins. All units shall have an independent refrigerant circuit per compressor and shall use a combination row/interlaced circuiting for efficient part load operation and to prevent air temperature stratification at partial load conditions. Each circuit shall be fed by an adjustable thermal expansion valve, with external equalizer, sized to provide efficient operation at full and at part load operating points. Plastic sleeves shall protect all distributor tubes.

All coils shall be factory leak tested with high pressure air under water.

Heating Coil

Hot water heat

A 1-row hot water heating coil shall be factory installed. Coils shall be fabricated of seamless 1/2" diameter copper tubing that is mechanically expanded into high efficiency aluminum plate fins. All coil vents and drains shall be factory installed. Access panels shall provide convenient access to the coil and valve for inspection and cleaning.

A factory-installed two-way [modulating] [on/off] control valve and actuator shall provide control of the hot water coil. The valve actuator shall be controlled by the factory installed main unit control system.

[Propylene glycol shall be added to the hot water circuit to protect against coil freeze-up.]

A factory-installed, non-averaging type freezestat shall provide some protection against coil freeze-up.

Coils shall be factory leak tested with high pressure air under water.

Electric heat

Staged electric heating coils shall be factory installed in the unit heat section. Heating coils shall be visible and easily accessed for inspection and service. Heating coils shall be constructed of low watt density, nickel-chromium elements. Protection controls shall include automatic reset high limit control for each heater element with manual reset backup line break protection in each heater element branch circuit. Heating element branch circuits shall be individually fused to a maximum of 48 amps per NEC requirements.

Multiple full magnetic line break contactors shall be controlled by the factory installed main unit control system to provide multiple stages of control.

Condensing Section

Condensers

Condensers shall be a counter flow, tube and tube design with all nonferrous water channels. Each condenser shall be on an independent refrigerant circuit and shall provide liquid sub-cooling for optimum system performance. Condensers shall be rated for 400 psig refrigerant working pressure. Each condenser shall be suitable for 400 psig waterside working pressure and shall be mechanically cleanable. All factory piping shall be capable of a waterside working pressure of 400 psig. Condensers shall be factory piped to provide for single field condenser water supply and return connections.

Units provided with condensers that are not mechanically cleanable will not be acceptable.

Condensers shall be factory leak tested with high pressure air under water. The completed condenser and interconnecting piping assembly shall be factory leak tested.

Condenser head pressure control (Not available with water economizer)

Mechanical cooling shall be available whenever entering condenser water temperatures are 55ºF or warmer, without the use of head pressure control. For entering condenser water temperatures below 55ºF, a factory installed and controlled 2-way modulating head pressure control valve shall be provided. The valve actuator shall be controlled through the factory installed main unit control system to maintain refrigerant head pressure at entering condenser water temperatures as low as 40°F.

66 McQuay Cat 860-7


Compressors

Each unit shall have multiple, heavy-duty [scroll (6 to 15 hp selections)] [reciprocating (20 hp selection)] compressors. Each compressor shall include [an independent refrigerant circuit and suction and discharge service valves with gauge ports], [crankcase heater (20 hp only)], sight-glass, anti-slug protection, motor overload protection and a time delay to prevent short cycling and simultaneous starting of compressors following a power failure. Compressors shall be isolated on resilient rubber isolators to decrease noise transmission. The number of compressors shall be as shown on the unit schedule.

Refrigeration controls

Each unit shall have multiple independent refrigeration circuits. Each circuit shall include a filter-drier, liquid moisture indicator/sight-glass, thermal expansion valve, liquid line shutoff valve with charging port [discharge line shutoff valve,] and high pressure relief device. The thermal expansion valve shall be capable of modulation from 100% to 25% of its rated capacity. [Units with independent refrigerant circuits shall be provided with isolation shutoff valves for each compressor and the filter drier/sight glass.] Sight-glasses shall be accessible for viewing without disrupting unit operation.

Each refrigerant circuit shall have a high and low-pressure cutout switch and a coil frost protection thermostat. The high pressure cutout shall be a manual reset control. Each low pressure control (loss of charge) and frost protection thermostat shall require a manual reset if the alarm condition occurs three times within any 24-hour period. Each refrigerant circuit shall be evacuated, leak tested, and fully charged with [R-22] [R-407C] and oil.

Refrigeration Capacity Control

Refrigeration capacity control shall be accomplished by staging of the unit's multiple compressors. To maintain desired temperature control, the unit shall have a minimum of [two] [three] [four] [six] steps of capacity control.

All compressor capacity control staging shall be controlled by the factory installed main unit control system. [Hot gas bypass will be provided on the first compressor circuit on dual refrigerant circuit units.]

Acoustic Discharge Plenum

Units shall be provided with a [factory mounted] [field mounted] acoustically treated discharge plenum with horizontal duct connection(s). [Single] [Multiple] duct connections shall be as indicated on the plans and shall be configured at the factory prior to shipment. Field cutting of discharge openings shall not be required.

The plenum shall be constructed of a minimum of 16-gauge galvanized steel. The plenum wall shall be insulated with 3" of 3 lb. density glass fiber insulation and the entire interior lined with a 20-gauge, 23% open, galvanized steel perforated liner for added rigidity and acoustic performance. For aesthetics and long term durability, the complete plenum exterior shall be constructed of the same pre-painted galvanized steel as the base unit. The use of single wall plenums is not acceptable.

To reduce turbulence in the plenum and improve performance, the plenum shall have acoustic baffles installed at the plenum corners. Plenums with a single side discharge opening or a single side with either a front or back opening shall have an acoustic baffle isolating the unused portion of the plenum.

Electrical

Unit wiring shall comply with NEC requirements and with all applicable UL standards. All electrical components shall be UL recognized, where applicable. To provide for easy identification, all wiring and electrical components shall be numbered, color-coded and labeled according to the electrical diagrams provided with each unit. The main unit control panel shall be completely factory wired and contained in an accessible enclosure. The main control panel shall be provided with dead front covers over all line voltage components. A terminal board shall be provided for low voltage control wiring. Branch circuit fusing, 115 V control circuit transformer with fuse, system switches and high temperature sensor shall also be provided.

Pilot knockouts shall be provided at the main control panel for field wiring entrance. The unit shall have a [single] [dual] [terminal block] [non-fused disconnect] for main unit power connection.

Each compressor shall be controlled by its own dedicated contactor, circuit breaker, manual motor protector, and temperature sensing overload. The supply fan motor circuit shall include a dedicated contactor, external line break overload protection and dedicated fuse protection. Group short circuit protection of components in lieu of individual short circuit protection for each component is not acceptable.

The unit control system shall permit starting and stopping of the unit locally or remotely. The keypad/display and monitoring panel shall include a three position “on,” “off,” “auto” switch, an Alarm indication light and a Power indication light. The Alarm light shall provide a visual indication whenever a malfunction occurs and it shall remain until the malfunction is corrected. The control system shall be capable of providing a remote alarm indication. The unit control system shall provide for pump start, outside air damper actuation, smoke shutdown, emergency shutdown, remote heat enable/disable, remote cool enable/disable, heat indication, cool indication, fan interlock and fan operation.

McQuay Cat 860-7 67


Non-fused disconnect switch

[A single non-fused disconnect switch shall be provided for disconnecting electrical power at the unit. The switch handle shall be visible, located at the front of the unit, and shall be accessible without unit entrance.]

[Dual non-fused disconnect switches shall be provided for disconnecting electrical power at the unit. One switch will service the supply fan plus the unit control system. The second switch will service the compressors. Disconnect switch handles shall be visible, located at the front of the unit, and shall be accessible without unit entrance.]

Phase failure/under voltage protection

A phase failure/under voltage protection device shall be provided to protect three-phase motors from damage due to single phasing, phase reversal and low voltage conditions.

Water flow switch

A water flow switch shall be provided, factory installed, to verify water flow status at the unit. Compressor operation shall be disabled and an alarm signal provided if condenser water flow is lost. Unit operation will be restored when water flow has again been sensed. Water flow status shall be displayed at the unit's main controller.

Freezestat (units with waterside economizer)

A non-averaging type freezestat shall be factory installed on the entering face of the economizer coil. Upon sensing a freeze condition, the unit supply air fan will be shut down, the [economizer] [heating] [economizer and heating] valve will be driven to the full open position and an alarm signal will be provided. Unit operation will be restored following the manual reset of the freezestat.

Freezestat (units without waterside economizer)

A non-averaging type freezestat shall be factory installed on the leaving face of the hot water heating coil. Upon sensing a freeze condition, the unit supply air fan will be shut down, the heating valve will be driven to the full open position and an alarm signal will be provided. Unit operation will be restored following the manual reset of the freezestat.

Battery pack

[The unit shall be provided with a factory mounted and wired rechargeable battery pack. The battery pack shall be available to provide control power to unit actuators in the event of a power failure.]

UV lights

Unit to have factory-mounted UV lights located on the leaving air side of the cooling coil. Unit to have view port to allow for visual indication of operation through UV resistant glass. Unit to have door interlocks on each removable panel accessing UV

light. Interlock to kill power to UV light when panel is removed.

Lamp and fixture to consist of a housing, power source, lamp sockets, and lamp. All components are to be constructed to withstand typical HVAC environments and are UL/C-UL listed. Housings are to be constructed of type 304 stainless steel and are to be equipped with both male and female power plugs with one type at each end to facilitate simple fixture-to-fixture plug-in for AC power.

Power source shall be an electric, rapid-type with overload protections and is to be designed to maximize radiance and reliability at UL/C-UL listed temperatures of 55°F–135°F. Power source will include RF and EMI suppression.

Sockets shall be medium bi-pin, single click safety, twist lock type and are to constructed of a UVC-resistant polycarbonate.

Lamp shall be a high output, hot cathode, T8 diameter, medium bi-pin that produces UVGI of 254 nm. Each tube produces the specified output at 500 fpm and air temperatures of 55°F–135°F.


Each unit shall be equipped with a complete MicroTech II microprocessor based control system. The unit control sys-tem shall include all required temperature and pressure sensors, compressor control boards, main microprocessor control board and operator interface. The unit control system shall perform all unit control functions including scheduling, [constant air volume, zone temperature control (SCC)] [constant air volume, discharge temperature control (DAC)] [variable air volume, cooling only discharge temperature control [with single-stage morning warm-up heat] (DAC)] [variable air volume, cooling/modulating heating discharge temperature control (DAC)] [duct static pressure control], [building static pressure control], unit diagnostics and safeties. All boards shall be individually replaceable for ease of service. All microprocessors, boards, and sensors shall be factory mounted, wired and tested.

The microprocessor shall be a stand-alone DDC controller not dependent on communications with any on-site or remote PC or master control panel. The microprocessor shall maintain existing set points and operate stand alone if the unit loses either direct connect or network communications. The microprocessor memory shall be protected from voltage fluctuations as well as any extended power failures. All factory and user set schedules and control points shall be maintained in nonvolatile memory. No settings shall be lost, even during extended power shutdowns.

The main microprocessor shall support an RS-232 direct connection to a product service tool or a modem. A [BACnet/IP] [BACnet MS/TP] [LonTalk] communications port shall be provided for direct connection into the BAS network.

68 McQuay Cat 860-7

All digital inputs and outputs shall be protected against damage from transients or wrong voltages. Each digital input and digital output on the main microprocessor shall be equipped with an LED for ease of service. An alarm LED on the user interface shall provide quick visual identification that an alarm condition exists. All field wiring shall be terminated at a separate, clearly marked terminal strip.

The microprocessor shall have a built-in time schedule. The schedule shall be programmable from the unit keypad interface. The schedule shall be maintained in nonvolatile memory to insure that it is not lost during a power failure. There shall be one start/stop per day and a separate holiday schedule. The controller shall accept up to sixteen holidays each with up to a 5-day duration. Each unit shall also have the ability to accept a time schedule via BAS network communications.

If the unit is to be programmed with a night setback or setup function, an optional space sensor shall be provided. Space sensors shall be available to support field selectable features. Sensor options shall include:• Zone sensor with tenant override switch.• #1 above plus a heating and cooling set point adjustment.

(SCC only)

The unit keypad/display character format shall be 20 characters × 4 lines. The character font shall be 5 × 8 dot matrix. The display shall be a supertwist nematic (STN) LCD display with black characters on yellow background for high visibility. For ease of service, the display format shall be English language readout. Coded formats with look-up tables shall not be acceptable.

The keypad interface shall be equipped with eight individual touch-sensitive membrane key switches that allow convenient navigation and access to all control functions. All control settings shall be password protected against unauthorized changes.

The user interaction with the display shall provide the following information as a minimum:1 Return air temperature 2 Supply air temperature3 Outdoor air temperature (opt.)4 Space air temperature (opt.)5 Discharge air temperature 6 Entering condenser water temperature7 Leaving condenser water temperature8 Mixed air temperature9 Outdoor enthalpy high/low (opt.)

10 Dirty filter indication 11 Airflow verification12 Supply fan status13 Supply vane position/VFD speed indication14 Outside air damper position(opt.)15 Duct static pressure 16 Duct static pressure #2 (opt.) 17 Building static pressure (opt.)

18 Cooling status19 Cooling control method

a Nearestb Average

20 Heating status21 Dehumidification status22 Control Temperature (changeover)23 External exhaust fan status (opt.)24 VAV output status25 Fan operation status26 Unit status27 Time schedules28 Up to four active alarms with time and date29 Previous 8 alarms with time and date30 Optimal start31 Purge cycle32 System operating hours

a Fanb Coolingc Individual compressord Heatinge Economizerf Tenant overrideg Dehumidification

The user interaction with the keypad shall provide the following set points as a minimum:1 Control modes

a Off manualb Autoc Heat/coold Cool only e Heat onlyf Fan only

2 Occupancy modea Autob Occupiedc Unoccupiedd Tenant override

3 Control temperature (changeover)a Return air temperatureb Space temperaturec Network signald Outdoor air temp. (VAV w/mod. heat)

4 Cooling with dead band 5 Heating with dead band 6 Cooling and heating supply 7 Cooling & heating supply reset options

a Return air temperature

McQuay Cat 860-7 69

b Outdoor air temperaturec Space temperatured Airflow (VAV)e No reset f Network signalg External (1-5 VDC)

8 Temperature alarm limitsa High supply air temperatureb Low supply air temperature c High return air temperature

9 Lockout control a Compressor lockoutb Heat lockout

10 Lead-lag on compressors a Autob Disabled

11 Compressor Inter-stage timers12 Night setback and setup space temp.13 Duct static pressure reset options

a No resetb Network

14 Building static pressure (optional)15 Minimum outdoor airflow reset

a Percent of cfm capacityb External reset (1–5 VDC)c Fixed outdoor damper position

16 Economizer changeovera Enthalpyb Dry bulb

17 Current time and date18 Tenant override time19 Occupied/unoccupied time schedules20 One event schedule21 Holiday dates and duration22 Service mode

a Timers normal (all time delays normal)b Timers fast (all time delays 20 sec.)c Mode normal (unit on)

Open Protocol Communications

The unit control system shall have the ability to communicate to an independent Building Automation System (BAS) through a direct [BACnet/IP] [BACnet MS/TP] [LonTalk] communications connection.

[BACnet Communications shall conform to the BACnet protocol (ANSI/ASHRAE135-2001). A protocol implementation conformance statement (PICS) shall be provided. Multiple units may be connected in a common communications network.]

[Communications shall conform to LONMARK Interoperability Guidelines and shall be certified. Controls shall conform to the [Discharge Air Controller (DAC)] [Space Comfort Controller (SCC)] profile.]

Through communications, the BAS System Integration (SI) Contractor shall be capable of interacting with the individual self-contained unit controllers in the following ways:1 Access to [quantity and description from specification]

“read only” variables and [quantity and description from specification] “read and write” variables.

2 Set the unit's operating mode.3 Monitor controller inputs, outputs, set points, parameters

and alarms.4 Change controller set points and configuration parameters.5 Clear alarms.6 Reset the cooling discharge air temperature set point (DAC

units).7 Reset the heating discharge air temperature set point (DAC

units with modulating heat).8 Reset the duct static pressure set point (DAC units).9 Set the heat/cool changeover temperature (DAC units).

10 Set the representative zone temperature (SCC units).

It will be the responsibility of the SI Contractor to integrate the self-contained unit data into the BAS to affect the integrated building control logic and centralized system workstation interface.

70 McQuay Cat 860-7

© 2007 McQuay International • www.mcquay.com • 800-432-1342 03/07

McQuay Training and Development

Now that you have made an investment in modern, efficient McQuay equipment, its care should be a high priority. For training information on all McQuay HVAC products, please visit us at www.mcquay.com and click on training, or call 540-248-9646 and ask for the Training Department.

WarrantyAll McQuay equipment is sold pursuant to its standard terms and conditions of sale, including Limited Product Warranty. Consult your local McQuay Representative for warranty details. Refer to Form 933-43285Y. To find your local McQuay Representative, go to www.mcquay.com.

This document contains the most current product information as of this printing. For the most up-to-date product information, please go to www.mcquay.com.

Self-Contained Air Conditioning System - Daikin Applied

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Transcript of Self-Contained Air Conditioning System - Daikin Applied