McQuay SWT028C Installation and Maintenance Manual

Brand: McQuay

Model: SWT028C

Category: Split-system air conditioners

Type: Installation and Maintenance Manual

This manual is also suitable for

Self-contained Air Conditioning System

Type SWT “C” Vintage Sizes 18 thru 40

Installation and Maintenance IM-709

Group: Applied Systems

Part Number: IM709

Date: January 2002

MEA

368-93-E

2 IM709

Table of Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Vibration Isolators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Location/Service Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Removal of Shipping Restraints and Construction Filter . . . . . . . . 4

Disassembly of Sections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Field Mounting of Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Units with fan section shipped separate (code 21=*M) . . . . . . 6

Units ordered for modular construction (code 32=1) . . . . . . . . 6

Refrigerant Piping . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Pressure Relief Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Water Connections . . . . . . . . . . . . . . . . . . . . . . . . . 8

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Condenser Piping 8

Condensate Drain Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Duct Connections . . . . . . . . . . . . . . . . . . . . . . . . . 11

Supply Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Return Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Physical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . . 15

Unit Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Field Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Unit Disconnect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Return Air and Outside Air Sensor. . . . . . . . . . . . . . . . . . . . . . . . . 19

Supply Power Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Lug Sizes For Single Disconnect or Power Block . . . . . . . . . . . . . 20

Control Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Electrical Legend . . . . . . . . . . . . . . . . . . . . . . . . . 22

Typical Wiring Schematics . . . . . . . . . . . . . . . . . . 23

Figure 18. Power Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 19. Input Schematic, Discharge Air Control (DAC). . . . . . . 24

Figure 20. Input Schematic, Zone or Space Comfort (SCC. . . . . . 25

Figure 21. Output Schematic, Actuator Control. . . . . . . . . . . . . . . 26

Figure 22. Output Schematic, Auxiliary Fan Start/Stop Control. . . 27

Figure 23 Output Schematic, Actuator Control . . . . . . . . . . . . . . . 28

Figure 24. Output Schematic, Compressor Control

(4 Compressors /4, 5 or 6 Stage). . . . . . . . . . . . . . . . . 29

Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . 30

High Pressure Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Low Pressure Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Compressor Motor Protector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Proof of Airflow Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Frost Protection Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Clogged Filter Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Unit Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Duct High Limit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Phase Fail/Under Voltage Protection . . . . . . . . . . . . . . . . . . . . . . . 31

Duct Static Pressure Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Building Static Pressure Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Building pressurization applications . . . . . . . . . . . . . . . . . . . . . . . . 32

Freezestat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Condenser Water Flow Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Water Side Economizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Condenser Water, Head Pressure Control . . . . . . . . . . . . . . . . . . 32

Variable Inlet Vanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Variable Frequency Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Disconnect Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Dual Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Electric Heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Hot Water Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

System Check, Test and Start . . . . . . . . . . . . . . . 34

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Pre Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Fan start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Compressor start-up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Economizer start-up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Hot water start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Expansion valve superheat adjustment . . . . . . . . . . . . . . . . . 35

Refrigerant Charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Variable air volume (VAV) start-up . . . . . . . . . . . . . . . . . . . . 37

Rpm changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Drive sheave alignment and belt tension . . . . . . . . . . . . . . . 37

Maintaining control parameter records . . . . . . . . . . . . . . . . . 37

System Maintenance . . . . . . . . . . . . . . . . . . . . . . . 38

Preventative Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Motor Bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . 39

Service and Warranty Procedure . . . . . . . . . . . . . 40

In Warranty Return Material Procedure . . . . . . . . . . . . . . . . . . . . . 40

Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Product Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

System Check, Test and Start Form . . . . . . . . . . 41

IM709 3

Introduction

General Description

Models SWTO18C through 040C are factory assembled,

refrigerant charged and tested, water cooled packaged air

conditioning units designed for ducted applications.

Each unit is comprised of three distinct sections:

●

Main cooling/heating

●

Filter/waterside economizer

●

Fan section

The unit is designed for easy disassembly for access to

mechanical rooms, freight elevators, etc. The disassembly of

the sections does not require the breaking of refrigeration

lines. When a unit is knocked down the maximum section

width including fastener heads is less than 341/2 inches.

Once in the mechanical room the unit is easily reassembled.

Each unit contains multiple scroll compressors, water cooled

condensers, multi-circuit evaporator, thermostatic expansion

valves, interconnecting refrigerant piping, forward curved

centrifugal fan, belt drive, fan motor, 4” pleated filters and

all necessary operating and safety controls.

All rigging, installation, power and control wiring external to

the unit, and condenser water and condensate piping are the

responsibility of the installer.

The MicroTech II™ self-contained unit controller is standard

equipment on “C” vintage units. For a detailed description of

the MicroTech components, input/output configurations,

field wiring options and requirements, and service proce-

dures, refer to Bulletin No. IM 710, “MicroTech II Self-con-

tained Unit Controller’ For a description of operation and

information on using and programming the MicroTech II

unit controller, refer to the appropriate operation manual

(see Table 1).

Table 1: Self-contained unit operation manual literature

Inspection

When the equipment is received, check all items carefully

checked against the bill of lading to verify a complete ship-

ment. The shipping receipt should not be signed until all

items have been accounted for. All units should be carefully

inspected for damage upon arrival. All shipping damage

should be reported to the carrier and a claim filed. The unit

serial plate should be checked before unloading the unit to be

sure that it agrees with the power supply available

SELF CONTAINED UNIT

CONTROL CONFIGURATION

OPERATION MANUAL

BULLETIN NUMBER

Discharge Air Control (VAV or CAV) OM 711

Space Comfort Control (CAV-ZTC) OM 712

Nomenclature

SWT-040-C

Self-contained

Water cooled

Top discharge

Vintage

Nominal tons

4 IM709

Installation

Note: Installation and maintenance must be performed

only by qualified personnel who are familiar with

local codes and regulations, trained and experi-

enced with this type of equipment.

Handling

Units may be shipped in one or two sections. When the unit

is shipped in two sections the fan section is separate from the

base sections. Units are shipped with a protective covering

which should remain in place while the unit is being moved

to its final location. Note: Check for concealed damage as

soon as possible.

Never allow any part of the unit to fall during unloading or

moving as this may result in serious damage. When the fan

section ships separate, lifting lugs are provided for rigging

and handling. The lugs are mounted on the fan section. If the

fan section ships attached to the base sections, lifting lugs

are not provided.

The unit base sections will accept lifting rods through chan-

nels on the base rail. If units are lifted by crane, protection

against chaffing damage by slings or cable must be provided

and spreader bars must be used across the top of the cabinet

to prevent structural damage to the frame.

Floor surfaces must be protected when equipment is moved

across finished flooring. Plywood sheeting may be used to

protect surfaces and distribute weight loading.

Vibration Isolators

All units are provided with 1” neoprene isolation pads,

shipped separately. Pads are to be installed beneath the unit

and located at each corner and the center of each base channel.

For units provided with more than (8) isolator pads, evenly

space the additional pads under the front and rear base chan-

nels.

Location/Service Access

For good installation, service and maintenance access the

following recommended clearances should be followed.

Clearance is required to allow room for side filter access,

mechanical cleaning of the condenser tubes and economizer

coil, access to expansion valves and other control compo-

nents and to allow for possible fan shaft or compressor

removal

Figure 1: Recommended Service and Maintenance

Clearance

Removal of Shipping Restraints and

Construction Filter

Mechanical restraints are used to secure the spring mounted

fan during shipment. Restraints and shipping blocks must be

removed after unit has been set in its final location.

CAUTION

Sharp edges and coil surfaces are a potential

injury hazard. Avoid contact with them.

CAUTION

Do not attempt to install dollies in the center of

the unit.

CAUTION

Units must not be moved in an upended position.

Unit front - 42"

Unit rear - 24"

Unit left side- 36"

Unit right side - 36"

Airflow

24"

42"

Evaporator Coil

Compressors

36"

24"

36"

1111342

AFD

IM709 5

Disassembly of Sections

If units are ordered for modular construction, they may be

easily disassembled into three sections. The figures below

illustrate the main cooling/heating, filter/waterside econo-

mizer, and fan sections. The thick lines in the figures show

where the sections are disassembled. The section are secured

by connection plates and screws. The following information

describes the location of the connecting points.

Fan section — base sections disassembly

The fan section sits on the base sections and is secured with

four steel plates. Each plate has two screws in the base sec-

tions and two screws in the fan section. Two of the plates are

shown in Figure 3. The connection plates are also the rigging

plates for the fan section only. They must not be used for rig-

ging the entire unit.

Main cooling/heating — filter/waterside economizer

sections disassembly

The following information is for units ordered for modular

construction (code 32=1). Note: The disassembly of units

not ordered for modular construction (code 32=Y) will

require field modification. Units not ordered for modular

construction do not have victaulic couplings on the water

pipes and the various control sensors are mounted in the unit.

●

Two steel plates the height of the sections connect the

main cooling/heating and the filter/waterside econo-

mizer sections. The plates are secured with multiple

screws on the right and left side of the base sections.

The connection plate and screws are illustrated in Sect

A-A.

●

The filter/waterside economizer section overlaps the

main cooling/heating sections along the bottom and top

adjoining rails. Multiple screws connect the two sec-

tions along these bottom and top overlaps.

●

Victaulic couplings connect the water pipes between the

filter/waterside and main cooling/heating sections. Each

victaulic coupling is secured with two bolts

●

.The condensate drain pipe between the two sections is

connected by a flexible PVC tube with pipe clamps.

Fan

Outlets

FILTER SECTION

EVAPORATOR

HEATER

ELECTRICAL PANEL

ECONOMIZER

Fan

Section

Main Cooling/

Heating Section

Filter/Waterside

Economizer

Section

Condenser

Compressor

Connection Plates

(2)

Figure 2

Figure 3

(1) Unit sizes 018, 023 and 028 have a single fan.

(2) Connection Plates are also the Rigging Plates for the Fan Section only.

ASD

(Optional)

6 IM709

Field Mounting of Sensors

Units with fan section shipped separate

(code 21=*M)

The following items require field connection or mounting

when the fan section is shipped separate:

• Fan Motor(s) power harness(es) need to be connected to

the OL10 overload(s) on the control board. The power har-

ness is located in the fan section with one end connected to

the fan motor. The other end of the power harness needs to

be connected to the control panel. Three penetration hole are

provide to the control panel. The holes are pre-punched in

the upper right hand side of the control panel when facing

the control panel. Select one of the holes and cut out the

insulation. Mount the power harness conduit fitting in the

hole. Connect the three fan power wires to the leaving side

of the OL1 0 overload.

• Supply Air Sensor — The sensor will be shipped

loose in the main cooling/heating section on the right side

when facing the control panel. The sensor will be labeled

SAT. Move the SAT sensor into the fan section. The mount-

ing location is on the right side of the fan section when fac-

ing the unit front. The mounting hole is labeled SAT on a

plate at the bottom of the fan.

• Duct High Limit Tube — The tube is shipped loose in

the main cooling/heating section on the left side when facing

the unit front. The tube is labeled DHL. The duct high limit

tube should be mounted on the left side of the fan section

regardless of front or back discharge. The mounting location

is labeled DHL TUBE on the flex duct metal. Place tube and

holder through flex duct assembly and screw locking nut on

the inside of the fan.

• VIV (optional) actuator and feedback potenti-

ometer control wire need to be connected. The VIV control

wiring penetrates the control board in the upper left corner

when facing the front of the unit. The connectors from the

control board are shipped loose in the main cooling/heating

section. The connectors from the VIV actuator are shipped

loose in the fan section. The control wire coming from the

actuator motor has a socket connector which matches the

prong connector from the control panel. The control wire for

the feedback potentiometer has a prong connector which

matches the socket connector from the control panel. This

logic of prong and socket connections prevents cross wiring

of the actuator motor and feedback potentiometer control

wiring.

Units ordered for modular construction

(code 32=1)

Right side of unit

The following items require field connection or mounting in

the filter/waterside economizer section. Each item is shipped

loose in the main cooling/ heating section. The four items are

located on the right side of the section when facing the front

of the unit. A hole is provided leaving the main cooling/heat-

ing section entering the filter/waterside economizer section.

Each item needs to be threaded through this hole into the fil-

ter/waterside economizer section. The mounting location of

the four items is the space after the filters and before the

coils. The following provide mounting hole locations for

each item:

• Mixed Air Sensor - Identify the sensor labeled MAT.

Mount the sensor in the 2nd hole from the top labeled MAT.

• Plastic Tube for Air Flow and Clogged Filter

Switch - The tube for pressure sensing on the Proof of Air

Flow Switch (PC7) and the Clogged Filter Switch (PC5) is

labeled PC5/PC7.

• Freezstat— If the optional Freezstat is ordered its con-

trol wiring must be connected. Plug the control wiring into

the freezstat mounted on the top hole.

Left or right side of unit

The following items are located on the same side of the unit

as the water piping connections. The water piping connec-

tions may be ordered right or left hand. Each of these items

requires field mounting or connections.

• Mount the EWT and LWT temperature sensors in the

filter/waterside economizer section. The sensors are shipped

loose on the bottom of main cooling/heating section on the

side of the water connections. Identify the sensor labeled

EWT and mount to the holder at the bottom the entering

water tube. The entering water tube is the bottom tube and is

labeled at the point it penetrates the unit. Identify the sensor

labeled LWT and mount to the holder at the bottom of the

leaving water tube. The leaving water tube is above the

entering water tube and is labeled at the point it penetrates

the unit.

• Connect the control wiring for the valve(s) actuator and

feedback potentiometer which control the water flow

through the waterside economizer (optional) and condenser.

The wire connectors from the control board are shipped

loose in the base of the main cooling/heating section. The

wire connectors from the valve actuator(s) are shipped loose

in the base of filter/waterside economizer section. The con-

trol wire coming from the actuator motor has a socket con-

nector which matches the prong connector from the control

panel. If there is more than one actuator motor, the wire

number on the socket connector must match the wire number

on the prong connector. If the wire numbers are not matched,

the valves will not be controlled properly. The control wire

for the feedback potentiometer has a prong connector which

matches the socket connector from the control panel. This

logic of prong and socket connections prevents cross wiring

of the actuator motor and feedback potentiometer control

wiring.

IM709 7

Refrigerant Piping

Pressure Relief Valves

All units have individual condensers per refrigerant circuit

and each condenser is provided with a spring loaded relief

valve. The valve is set to open when refrigerant pressure

reaches 400 psig. The relief valve will accommodate a 1/2"

flare connection for applications where it is necessary to

connect vent piping and run it outside the building.

CAUTION

When refrigerant is vented to the outside of the

building, install the vent piping as recommended

in ASHRAE Standard 15-1992.

8 IM709

Water Connections

General

Due to the variety of piping practices, follow the recommen-

dations of local authorities. They can supply the installer

with the proper building and safety codes required for code-

compliant proper installation.

Basically, the piping should be installed with a minimum

number of bends and elevation changes for best perfor-

mance. Piping should contain:

1. Vibration eliminators to reduce vibration and noise

transmission to the building.

2. Shutoff valves to isolate the unit from the piping system

during unit servicing.

3. Manual or automatic air vent valves at the high points of

the system.

4. Some means of maintaining adequate system water

pressure (e.g., expansion tank or regulating valve).

5. Temperature and pressure indicators located at the unit

to aid in servicing.

6. A strainer or some means of removing foreign matter

from the water before it enters the pump. It should be

placed far enough upstream to prevent cavitation at the

pump inlet (consult pump manufacturer for recommen-

dations). The use of a strainer will help prolong pump

life and help maintain system performance.

7. Size piping to minimize system pressure drop.

Condenser Piping

1. Units may be specified with water and condensate con-

nections on either end of the unit.

2. All units have an individual condenser per refrigerant

circuit. All condensers are factory piped for a common

condenser supply and a common condenser return con-

nection.

3. Field piping connections are made to factory provided

piping located as indicated on the unit submittal draw-

ings. Units with factory provided water side economizer

coil have the piping connections run to the outside of

the unit cabinet. Connections are located behind a fac-

tory mounted shipping cover. Connections are located

behind a factory mounted cover plate. All connections

are copper, sweat connections as indicated on unit

dimensional drawings.

4. Supply and return water connections must be made at

the proper locations as indicated by the dimensional

drawings. Supply (water in) connection is always the

lower connection.

5. Units with factory mounted water side economizer

should not require head pressure control. The econo-

mizer will typically elevate the water temperature by 5

to 10°F before entering the condenser, allowing suitable

condenser water temperatures whenever the tower sup-

ply temperature is 50°F or higher. Without head pres-

sure control, mechanical cooling is locked out below

55°F EWT.

6. Head pressure control must be provided if no econo-

mizer is used and if entering condenser water tempera-

tures will go below 55°F. Fan cycling and/or modulating

discharge dampers on the cooling tower are often used,

or a 3-way bypass around the tower. Cooling tower con-

trol to maintain the temperature at >55°F is generally

more cost effective if multiple units are in the loop. If

valves are installed on the individual SWP units, a sin-

gle water regulating valve controlled by circuit #1 head

pressure should be used. The Lead/Lag option must

equal “NO”. When Lead/Lag equals “NO” circuit #1 is

always first on and last off. The refrigerant pressure line

from the valve should be connected to a gauge port on

any liquid line service valve located in compressor #1

refrigerant circuit. Compressor #1 is located at the far

left of the cabinet.

Figure 4. Condenser Regulating Valve (refrigerant

pressure controlled

)

If the water regulating valve is placed in series with the unit

condensers, it should be installed in the water line leaving

the condenser and should shutdown to prevent water from

siphoning out of the condensers. For systems where a con-

stant pumping head is required, the water regulating valve

may be installed in a bypass line around the condensers. It

must then open on falling discharge pressure.

These typical systems, depending on the specific application,

must maintain a constant condensing pressure regardless of

temperature conditions and must assure adequate head pres-

sure for proper thermostatic expansion valve operation. A

minimum head pressure of 160 psig (86°F condensing tem-

perature) is recommended.

7. Condenser tube velocities must not exceed 10 feet per

second. Flow and velocity will be satisfactory if water

volumes do not exceed those shown in Table No. 4.

IM709 9

Figure 5. Condenser water pressure drop

SWT018C-028C

Figure 6. Condenser water pressure drop

SWT035C-040C

Figure 7. Waterside economizer pressure drop

SWT018C-040C

Figure 8. Hot water coil pressure drop SWT035C-040C

Water Flow Rate - gpm (L/s)

(1.2)

(1.9)

(2.5)

(3.2)

(3.8)

(4.4)

(5.1)

(5.7)

100

(6.3)

150

(9.5)

Water Pressure Drop (kPa) ft. w.g.

(60) 20

(45) 15

(30) 10

(27) 9

(24) 8

(21) 7

(18) 6

(15) 5

(12) 4

(9) 3

(6) 2

Note:

HP = total unit compressor horsepower

30 hp

10 hp

15 hp

20 hp

25 hp

Water Pressure Drop (kPa) ft. w.g.

(60) 20

(45) 15

(30) 10

(27) 9

(24) 8

(21) 7

(18) 6

(15) 5

(12) 4

(9) 3

Water Flow Rate - gpm (L/s)

(2.5)

(3.2)

(3.8)

(4.4)

(5.1)

(5.7)

100

(6.3)

150

(9.5)

Note:

HP = total unit compressor horsepower

200

(12.6)

40 hp

20 hp

25 hp

30 hp

35 hp

Water Flow Rate - gpm (L/s)

(2.5)

(3.2)

(3.8)

(4.4)

(5.1)

(5.7)

100

(6.3)

150

(9.5)

Note:

1. Includes coil, control valve and interconnecting piping.

2. Add this

)

P to condenser

)

P to obtain unit

)

P for pump selection.

200

(12.6)

Water Pressure Drop (kPa) ft. w.g.

(60) 20

(45) 15

(30) 10

(27) 9

(24) 8

(21) 7

(18) 6

(15) 5

(1.9)

(1.2)

(9) 3

(12) 4

(90) 30

(120) 40

(150) 50

(180) 60

(210) 70

018 - 028

035 - 040

(6) 2

Water Flow Rate - gpm (L/s)

(2.5)

(3.2)

(3.8)

(5.1)

100

(6.3)

150

(9.5)

(1.9)

(1.2)

Water Pressure Drop (kPa) ft. w.g.

(60) 20

(30) 10

(24) 8

(18) 6

(15) 5

(9) 3

(12) 4

(90) 30

(120) 40

(150) 50

(180) 60

(210) 70

018

023

035

028

040

Note: Includes coil, control valve and interconnecting piping.

10 IM709

Figure 9. Water regulating valve pressure drop

Head pressure control

Condensate Drain Connection

The condensate drain connection is 11/8" O.D.S. copper and

is located on the same end of the unit as the condenser water

connections. The drain is internally trapped at the factory

requiring no external trap. The condensate line should be

pitched away from the unit with a minimum slope of 1/8" per

foot. Drain pans and the drain trap should be kept clean by

periodic cleaning. A cleanout is provided as standard in the

trap to aid in cleaning.

018 - 028

035 - 040

Water Flow Rate - gpm (L/s)

(2.5)

(3.2)

(3.8)

(4.4)

(5.1)

(5.7)

100

(6.3)

150

(9.5)

Note:

Includes coil, control valve and interconnecting piping.

200

(12.6)

Water Pressure Drop (kPa) ft. w.g.

(60) 20

(45) 15

(30) 10

(27) 9

(24) 8

(21) 7

(18) 6

(15) 5

(1.9)

(9) 3

(12) 4

(90) 30

(105) 35

(6) 2

(1.2)

(120) 40

(75) 25

(3) 1

IM709 11

Duct Connections

Supply Air

For connection of supply ductwork directly to the unit, a

duct collar must first be mounted at the fan outlet, avoiding

the mounting screws located around the perimeter of the fan

discharge opening. Fan discharge opening sizes are indicated

on the unit dimensional drawings. When connecting duct-

work to the unit, use a canvas type connecting collar. To

maintain specified fan performance, two-fan units should

incorporate a properly designed "pants" duct connection

(refer to Figure 10).

Units are available in two fan configurations as shown in

Figure 11. Duct take-offs which go opposite to the direction

of fan rotation will result in an associated system effect loss

and reduced fan performance.

Figure 10. Two-fan unit top detail

Figure 11. Discharge duct configuration

12 IM709

Return Air

Air return to the unit can be arranged in different ways.

1. Ducted return

Return ductwork may be attached to the 2" flange around the

perimeter of unit's return air opening (refer to Figure 12).

Use a canvas type duct connecting collar. All ductwork con-

nected to the unit should be of adequate size and construc-

tion for the application. A canvas type connector is also

recommended where the duct penetrates the machine room

wall(s). This will help prevent vibration generated by air

movement in the duct from being transmitted out to the

occupied spaces.

Note: Do not obstruct unit access panel located below the

return opening.

Note: For units with ducted return, connect the open port

on the clogged filter switch (PC5) to the return air

duct.

2. Free return

The mechanical equipment room may be used as a return

plenum with no hard connection at the unit.

Note: Some building codes do not allow the use of the

mechanical room as a return plenum. Check appli-

cable local codes for each installation.

Figure 12. Return duct connections

IM709 13

Physical Data

Table 2. SWT018C-040C English units

Table 2a. SWT018C-040C SI units

DATA SWT MODEL SIZE

018C 023C 028C 035C 040C

COMPRESSOR

Quantity 2, 3, 4 3, 4 4 4 4

Size (see application chart, Table 4)

EVAPORATOR COIL

Face area (in2) 11.8 15.3 18.9 23.3 26 3

Rows 4, 6 4, 6 4, 6 4, 6 4, 6

FPI 12 12 12 12 12

PERFORMANCE

Nominal tons 13.6 19.7 25.8 31.1 35.6

WATERSIDE ECONOMIZER COIL

Face area (in2) 11.8 15.3 18.9 23.3 26.3

Rows 4 4 4 4 4

FPI 12 12 12 12 12

Max. working press. 400 400 400 400 400

HOT WATER HEATING COIL

Face area (in2) 9.3 12.8 16.3 20.2 23.8

Rows 1 1 1 1 1

FPI 12 12 12 12 12

ELECTRIC HEAT

kW 34 34 34 34 34

FILTERS

(Qty) size (in)

— — — (5) 20x20x4 (5) 20x20x4

(4) 2Ox20x4 (4) 20x20x4 (4) 20x20x4 (5) 25x20x4 (5) 25x20x4

(4) 25x20x4 (4) 25x20x4 (4) 25x20x4 — —

EVAPORATOR FAN

Quantity 1 1 1 2 2

Size (in) 15 18 18 15-15 15-15

Minimum hp 5 7.5 10 10 15

Maximum hp 10 15 20 20 25

Min. Design cfm, CV 2950 3825 4725 5825 6575

Min. Design cfm,

VAV

4720 6120 7560 9320 10520

Max. Design cfm 7080 9180 11340 13980 15780

CONDENSER

Quantity 2, 3, 4 3, 4 4 4 4

W.S. working press. 400 400 400 400 400

Min entering temp.

(F)

55 55 55 55 55

DATA SWT MODEL SIZE

018C 023C 028C 035C 040C

COMPRESSOR

Quantity 2, 3, 4 3, 4 4 4 4

Size (see application chart, Table 4)

EVAPORATOR COIL

Face area (m2) 1.10 1.42 1.76 2.16 2.44

Rows 4, 6 4, 6 4, 6 4, 6 4, 6

FPI 1212121212

PERFORMANCE

Nominal tons 13.6 19.7 25.8 31.1 35.6

WATERSIDE ECONOMIZER COIL

Face area (m2) 1.10 1.42 1.76 2.16 2.44

Rows 4 4 4 4 4

FPI 1212121212

Max. working press. 400 400 400 400 400

HOT WATER HEATING COIL

Face area (m2) 0.9 1.2 1.5 1.9 2.2

Rows 1 1 1 1 1

FPI 1212121212

ELECTRIC HEAT

kW 34 34 34 34 34

FILTERS

(Qty) size (mm)

———

(5)

508x508x102

(5)

508x508x102

(4)

508x508x102

(4)

508x508x102

(4)

508x508x102

(5)

508x508x102

(5)

508x508x102

(4)

508x508x102

(4)

508x508x102

(4)

508x508x102

——

EVAPORATOR FAN

Quantity 1 1 1 2 2

Size (in) 15 18 18 15-15 15-15

Minimum hp 5 7.5 10 10 15

Maximum hp 10 15 20 20 25

Min. Design L/s, CV 310 852 1053 1298 1465

Min. Design L/s, VAV 2228 2889 3568 4399 4965

Max. Design L/s 3342 4333 5352 6599 7448

CONDENSER

Quantity 2, 3, 4 3, 4 4 4 4

W.S. working

press.(Pa)

2.8 2.8 2.8 2.8 2.8

Min entering temp.

(C)

13 13 13 13 13

14 IM709

Table 3. Compressor circuit charge

* Charge quantities listed are averages. Actual charge quantity is dependent

on individual unit evaporator coil circuiting. Actual charge quantities are

stamped on each unit nameplate.

Table 4. Compressor application chart

COMPRESSOR

(HP)

*REFRIGERANT

CHARGE PER

CIRCUIT (R-22)

OIL CHARGE

PER CIRCUIT

(OZ.)

69 Ibs.53

10 14 lbs. 132

13 18 lbs. 128

SWT

MODEL

SIZE

COMPRESSOR HORSEPOWER MIN.

GPM

(L/s)

MAX

GPM

(L/s)

CKT#1

CKT#2

CKT#3

CKT#4

018C

6 6 - - 24 (1.5) 42 (2.7)

6 6 6 - 36 (2.3) 62 (4.0)

6 6 6 6 48 (3.0) 84 (5.3)

023C

6 6 6 - 35 (2.2) 65 (4.1)

6 6 6 6 48 (3.0) 84 (5.3)

6 6 6 6 58 (3.7) 102 (6.4)

6 6 6 10 58 (3.7) 102 (6.4)

6 6 10 10 68 (4.3) 119 (7.5)

028C

6 6 6 6 48 (3.0) 84 (5.3)

6 6 6 10 58 (3.7) 102 (6.4)

6 6 10 10 68 (4.3) 119 (7.5)

6 10 10 10 78 (4.9) 137 (8.7)

035C

6 6 6 10 58 (3.7) 102 (6.4)

6 6 10 10 68 (4.3) 119 (7.5)

6 10 10 10 78 (4.9) 137 (8.7)

10 10 10 10 88 (5.6) 154 (9.7)

040C

6 6 6 10 58 (3.7) 102 (6.4)

6 6 10 10 68 (4.3) 119 (7.5)

6 10 10 10 78 (4.9) 137 (8.7)

10 10 10 10 88 (5.6) 154 (9.7)

10 10 13 13 104 (6.5)

183

(11.5)

13 13 13 13 120 (7.6)

212

(13.4)

IM709 15

Dimensional Data

Figure 13. Left Side Front (CW) Discharge Figure 14. Left Side Back (CCW) Discharge

Note: (1) Select unit arrangement on the unit selection.

(2) There are two victaulic connections for condenser water at

module split.

Table 5.

(1) Dimensions do not include handle, latch or fastener extensions.

(2) For shipping dimensions the skid adds 4” to Depth, 8” to Length and 4” to

Height.

BASIC UNIT 018C 023C 028C 035C 040C

A. DEPTH

(1) (2)

52.00 52.00 52.00 52.00 52.00

(1321mm) (1321mm) (1321mm) (1321mm) (1321mm)

B. LENGTH

(1)

(2)

84.00 84.00 84.00 84.00 84.00

(2134mm) (2134mm) (2134mm) (2134mm) (2134mm)

C. HEIGHT

(1) (2)

112.75 112.75 112.75 112.75 112.75

(2864mm) (2864mm) (2864mm) (2864mm) (2864mm)

D. FAN

DISCHARGE

18.62 21.88 21.88 18.62 18.62

(473mm) (556mm) (556mm) (473mm) (473mm)

E. FAN

DISCHARGE

15.88 18.88 18.88 15.88 15.88

(403mm) (480mm) (480mm) (403mm) (403mm)

BASIC UNIT 018C 023C 028C 035C 040C

F. UNIT SIDE

TO FAN

32.69 31.06 31.06 23.88 23.88

(830mm) (789mm) (789mm) (606mm) (606mm)

G. RETURN DUCT

HEIGHT

45.94 45.94 45.94 45.94 45.94

(1167mm) (1167mm) (1167mm) (1167mm) (1167mm)

H. RETURN DUCT

LENGTH

80.00 80.00 80.00 80.00 80.00

(2032mm) (2032mm) (2032mm) (2032mm) (2032mm)

J. WATER OUT/IN

(ODS)

2 1/82 1/82 1/82 5/82 5/8

K. HOT WATER

OUT/IN (ODS)

1 5/8 1 5/8 1 5/8 1 5/8 1 5/8

16 IM709

Figure 15. Unit Front Plan and Front Elevation

Notes:

1. Service connections determined when facing the front of

the unit. Left hand standard, right hand optional. Please indi-

cate on the unit submittal.

2. Unit sizes 018C, 023C and 028C have a single fan.

3. Unit sizes 018C, 023C and 028C have a single mechanical

access panel in bottom front and bottom back.

F FDD

15.0

(381)

6.46

(164)

34.0

(864)

78.5

(199.4)

72.0

(182.8)

Mechanical

Access

Power entry

7/8" (2.2) KO

Electrical

Access

MicroTech II

System

Indicator

Panel

Fan

Outlets

1.0 (25)Neoprene

Isolation Pads

shipped separately

Connection

Plate

Return Air

Unit Front Plan

Left side piping

connections

Right side piping

connections

(optional)

Supply fan motor

Front Elevation

(For dimentions B, D, E and F see Table 5)

ASD

(Optional)

IM709 17

Figure 16. Back Elevation and Left Side

Notes:

6. Filters are removable from the rear of the unit or through a

side filter access door, located on the piping connection side.

7. Length will be increased by approximately 3.5” (89mm),

for piping connections when water economizer option is

ordered.

8. Mechanical access panel(s) in the back of the unit start 2”

(51mm) below return duct opening. Do not obstruct the

access panel(s).

9. There are two access doors on 018C, 023C and 028C

instead of three as shown.

10. All dimensions are given in inches with millimeters in

parentheses.

11. All dimensions ± 0.25” (6.4mm).

18 IM709

Unit Weights

Table 6a. Unit and Component Weight

English Units in lbs.

(1) Water economizer weight includes valves and piping.

(2) Hot water coil weight includes valve piping

Table 6b. Unit and Component Weight

SI Units in kg.

(1) Water economizer weight includes valves and piping.

(2) Hot water coil weight includes valve piping

COMPONENT

UNIT SIZE

018C 023C 028C 035C 040C

MAIN COOLING/HEATING SECTION

Main Base 946 946 946 1045 1045

4 Row DX Coil 206 238 278 333 354

6 Row DX Coil 250 294 347 417 450

Comp./Cond. Water

(2) 6 hp 26 560 — — — —

(3) 6 hp 35 705 705 — — —

(4) 6 hp 43 856 856 856 856 —

(3) 6, (1) 10 hp 57 — 987 987 987 987

(2) 6, (2) 10 hp 66 — 1105 1105 1105 1105

(1) 6, (3) l0 hp 74 — — 1233 1233 1233

(4) 10 hp 95 — — — 1368 1368

(2) 10, (2) 13 hp — — — — — 1511

(4) 13 hp — — — — — 1654

Hot Water Coil,

1 Row, 12 fpi

(2)

71 97 119 130 152

HW Coil Water Weight 16 20 23 28 32

Electric Heat -34 kW 20 20 20 20 20

Skid for Main 99 99 99 115 115

FILTER/WATERSIDE ECONOMIZER SECTION

Base 368 368 428 428

Water Economizer Coil

4 Row

(1)

266 298 340 393 410

Economizer Water Weight 51 65 75 94 111

FAN SECTION

Fan & Frame 900 930 930 1120 1120

Skid for Fan Section 98 98 98 115 115

Supply Fan Motors

3 hp Open Dripproof 71 — — — —

5 hp Open Dripproof 82 — — — —

7 1/2 hp Open Dripproof 124 124 — — —

l0 hp Open Dripproof 144 144 144 144 —

l5 hp Open Dripproof — 185 185 185 185

20 hp Open Dripproof — — 214 214 214

25 hp Open Dripproof — — — — 266

3 hp Totally Enclosed 72 — — — —

5 hp Totally Enclosed 85 — — — —

71/2

hp Totally Enclosed

140 140 — — —

10 hp Totally Enclosed 170 170 170 170 —

15 hp Totally Enclosed — 235 235 235 235

20 hp Totally Enclosed — — 300 300 300

25 hp Totally Enclosed — — — — 330

COMPONENT

UNIT SIZE

018C 023C 028C 035C 040C

MAIN COOLING/HEATING SECTION

Main Base 429 429 429 474 474

4 Row DX Coil 94 108 126 151 161

6 Row DX Coil 113 133 157 189 204

Comp./Cond. Water

(2) 6 hp 12 254 — — — —

(3) 6 hp 16 320 320 — — —

(4) 6 hp 20 388 388 388 388 —

(3) 6, (1) 10 hp 26 — 448 448 448 448

(2) 6, (2) 10 hp 30 — 501 501 501 501

(1) 6, (3) l0 hp 34 — — 559 559 559

(4) 10 hp 43 — — — 621 621

(2) 10, (2) 13 hp — — — — — 680

(4) 13 hp — — — — — 744

Hot Water Coil,

1 Row, 12 fpi

(2)

32 44 54 59 69

HW Coil Water Weight 7 9 10 13 15

Electric Heat -34 kW 9 9 9 9 9

Skid for Main 45 45 45 52 52

FILTER/WATERSIDE ECONOMIZER SECTION

Base 167 167 167 194 194

Water Economizer Coil

4 Row

(1)

121 135 154 178 186

Economizer Water Weight 23 29 34 43 50

FAN SECTION

Fan & Frame 408 422 422 508 508

Skid for Fan Section 44 44 44 52 52

Supply Fan Motors

3 hp Open Dripproof 32 — — — —

5 hp Open Dripproof 37 — — — —

7 1/2 hp Open Dripproof 56 56 — — —

l0 hp Open Dripproof 65 65 65 65 —

l5 hp Open Dripproof — 84 84 84 84

20 hp Open Dripproof — — 97 97 97

25 hp Open Dripproof — — — — 121

3 hp Totally Enclosed 32 — — — —

5 hp Totally Enclosed 39 — — — —

71/2

hp Totally Enclosed

64 64 — — —

10 hp Totally Enclosed 77 77 77 77 —

15 hp Totally Enclosed — 107 107 107 107

20 hp Totally Enclosed — — 136 136 136

25 hp Totally Enclosed — — — — 150

IM709 19

Field Wiring

General

Wiring must comply with all applicable codes and ordi-

nances. The warranty does not cover equipment failures

caused by or contributed to wiring not in accordance with

specifications. An open fuse indicates a short, ground or

overload. Before replacing a fuse or restarting a compressor

or fan motor, the trouble must be found and corrected. Use

copper wire for all power lead terminations. Contact factory

for information concerning aluminum wire power lead ter-

minations.

A single power terminal block is provided as standard and

wiring within the unit is done in accordance with the

National Electric Code. All branch circuits within the control

panel are individually fused. A single field supplied discon-

nect is required or a unit mounted nonfused disconnect can

be ordered with the unit.

Table 7. Compressor Motors

A 7/8” knockout is located on the right-hand unit upright for

locating unit power entry. 24V field connections are suitable

for Class II wiring.

Unit Disconnect

Disconnecting means are addressed by Article 440 of the

National Electric Code (NEC) which requires disconnecting

means capable of disconnecting air conditioning and refrig-

erant equipment including motor-compressors, and control-

lers, from the circuit feeder." The disconnect switch should

be selected and located within the NEC guidelines. Location

requirements per NEC are that the disconnect be located in a

readily accessible position within sight (50 feet) of the unit.

A factory mounted nonfused disconnect is available.

Return Air and Outside Air Sensors

All units are provided with a return air sensor. The outside

air sensor is optional and can be ordered with the unit. The

return air sensor is connected to the input control board and

is coiled up and placed in the control box of the unit for ship-

ment. The return air sensor must be field installed in the

return air stream for proper unit operation. The outside air

sensor is shipped loose in a package and is located on the

floor of the fan section. The mixed air temperature sensor is

already installed at the inlet of the unit.

The sensors must be mounted in areas that are exposed to

representative temperature conditions. The sensor should be

mounted at a position that has good air mixing and does not

have stratification. The sensor can be mounted in the duct-

work using a grommet, see Figure 17.

Figure 17. Return/Outside Air Sensor Mounting

The return air sensor is connected to the unit’s input board at

location AI4, see IM710. The outside air sensor is field

wired to terminal strip TB2. The sensor is to be connected at

terminals 124 and 125.

Table 7. Compressor Motors

Table 8. Electric Heaters

Grommet

Sensor

Ductwork

Compressor

208/60/3 230/60/3 400/50/3 460/60/3 575/60/3

RLA LRA RLA LRA RLA LRA RLA LRA RLA LRA

17.9 156.0 16.2 156.0 8.1 70.0 8.1 70.0 6.5 54.0

31.2 239.0 28.2 239.0 14.1 125.0 14.1 125.0 11.3 80.0

35.6 350.0 32.0 350.0 16.0 158.0 16.0 158.0 12.8 125.0

SWP UNIT SIZE

208V/60HZ/3PH 230V/60HZ/3PH 400V/50HZ/3PH 460V/60HZ/3PH 575V/60HZ/3PH

kW MBH FLA kW MBH FLA kW MBH FLA kW MBH FLA kW MBH FLA

018 - 040

27.8 94 77.2 34 116 85.6 25.7 88 37.2 34 116 42.8 34 116 34.2

20 IM709

Table 9 Supply Fan Motor Data

Supply Power Wiring

1. Units require three-phase power supply.

2. Allowable voltage tolerances:

a. 60 Hertz

Nameplate 208V: Min.187V, Max. 229V

Nameplate 230V: Min.207V, Max. 253V

Nameplate 460V: Min.414V, Max. 506V

Nameplate 575V: Min.518V, Max. 632V

b. 50 Hertz

Nameplate 400V: Min. 342V, Max. 418V

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 FLA) + other

loads + 2 amps.

b. For units with cooling capability and non concurrent

electric heat capability:

In the cooling mode, the loads will be composed of

supply fan motor and compressors. In heating mode,

the loads will be composed of supply fan motor and

electric heater. The MCA is calculated for unit run-

ning in either mode; the highest value obtained is used

for the MCA.

(1) For unit in cooling mode:

MCA = 1.25 (largest RLA or FLA) + other loads +

2 amps.

(2) For unit in heating mode:

MCA = 1.25 (electric heat FLA + Fan FLA) + 2

amps.

4. Size wires in accordance with Table 310-16 or 310-19 of

the National Electrical Code.

5. Wires should be sized for a maximum of 3% voltage

drop.

Lug Sizes For Single Disconnect or

Power Block

Horsepower TYPE

208/60/3 230/60/3

400/50/3

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

High Efficiency 9.9 9.0 4.5 4.5 3.4

Premium Efficiency 9.3 8.2 4.1 4.1 3.1

High Efficiency 14.8 14.0 7.0 7.0 5.3

Premium Efficiency 15.7 13.6 6.8 6.8 5.2

7.5

High Efficiency 22.3 21.6 10.8 10.8 8.2

Premium Efficiency 22.3 20.0 10.0 10.0 7.4

High Efficiency 29.7 28.0 14.0 14.0 11.0

Premium Efficiency 29.0 25.8 12.9 12.9 10.3

High Efficiency 44.4 40.6 20.3 20.3 16.2

Premium Efficiency 43.4 37.8 18.9 18.9 14.1

High Efficiency 57.0 50.0 25.0 25.0 20.0

Premium Efficiency 57.0 49.0 24.5 24.5 18.9

High Efficiency 69.8 62.0 31.0 31.0 24.3

Premium Efficiency 70.5 61.0 30.5 30.5 24.2

Table 10. Single Disconnect

UNIT VOLTAGE SIZE (AMPS)

018-028

208/230 225

018-028

400/460 100

018-028

575 100

035-040

208/230 225

035-040

400/460 150

035

575 100

040

575 150

Table 11. Lug Sizes For Single Disconnect

DISCONNECT SIZE LUG SIZE

100

#6-2/0

150

#2-3/0

225

#3-300 MCM

Table 12. Lug Sizes For Power Block

UNIT VOLTAGE LUG SIZE

018-040

ALL #6-400 MCM

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McQuay SWT028C Installation and Maintenance Manual

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Model: SWT028C

Category: Split-system air conditioners

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