McQuay SWT028C Installation and Maintenance Manual

Category
Split-system air conditioners
Type
Installation and Maintenance Manual

This manual is also suitable for

© 2002 McQuay International
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
Copyright © 2002 McQuay International. All rights reserved throughout the world.
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"
or
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
AA
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 SensorThe 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)
20
(1.2)
30
(1.9)
40
(2.5)
50
(3.2)
60
(3.8)
70
(4.4)
80
(5.1)
90
(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)
40
(2.5)
50
(3.2)
60
(3.8)
70
(4.4)
80
(5.1)
90
(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)
40
(2.5)
50
(3.2)
60
(3.8)
70
(4.4)
80
(5.1)
90
(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
30
(1.9)
20
(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)
40
(2.5)
50
(3.2)
60
(3.8)
80
(5.1)
100
(6.3)
150
(9.5)
30
(1.9)
20
(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)
40
(2.5)
50
(3.2)
60
(3.8)
70
(4.4)
80
(5.1)
90
(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
30
(1.9)
(9) 3
(12) 4
(90) 30
(105) 35
(6) 2
20
(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)
E
6.46
(164)
34.0
(864)
78.5
(199.4)
B
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
HP
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
6
17.9 156.0 16.2 156.0 8.1 70.0 8.1 70.0 6.5 54.0
10
31.2 239.0 28.2 239.0 14.1 125.0 14.1 125.0 11.3 80.0
13
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
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
3
High Efficiency 9.9 9.0 4.5 4.5 3.4
Premium Efficiency 9.3 8.2 4.1 4.1 3.1
5
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
10
High Efficiency 29.7 28.0 14.0 14.0 11.0
Premium Efficiency 29.0 25.8 12.9 12.9 10.3
15
High Efficiency 44.4 40.6 20.3 20.3 16.2
Premium Efficiency 43.4 37.8 18.9 18.9 14.1
20
High Efficiency 57.0 50.0 25.0 25.0 20.0
Premium Efficiency 57.0 49.0 24.5 24.5 18.9
25
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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Split-system air conditioners
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