Ingersoll-Rand GAC180-300 Installation and operating instructions

SAFETY WARNING
Only qualified personnel should install and service the equipment. The installation, starting up, and servicing of heating, ventilating, and air-
conditioning equipment can be hazardous and requires specific knowledge and training. Improperly installed, adjusted or altered equipment
by an unqualified person could result in death or serious injury. When working on the equipment, observe all precautions in the literature and
on the tags, stickers, and labels that are attached to the equipment.
Packaged Rooftop Air Conditioners
Foundation™ Gas/Electric
15 – 25 Tons, 60Hz
Installation, Operation,
and Maintenance
Model Numbers: GAC180-300
GAD180-300
RT-SVX51B-EN
December 2014

© 2014 Trane All rights reserved RT-SVX51B-EN
Introduction
Read this manual thoroughly before operating or servicing
this unit.
Warnings, Cautions, and Notices
Safety advisories appear throughout this manual as
required. Your personal safety and the proper operation of
this machine depend upon the strict observance of these
precautions.
Important Environmental
Concerns
Scientific research has shown that certain man-made
chemicals can affect the earth’s naturally occurring
stratospheric ozone layer when released to the
atmosphere. In particular, several of the identified
chemicals that may affect the ozone layer are refrigerants
that contain Chlorine, Fluorine and Carbon (CFCs) and
those containing Hydrogen, Chlorine, Fluorine and
Carbon (HCFCs). Not all refrigerants containing these
compounds have the same potential impact to the
environment. Trane advocates the responsible handling of
all refrigerants-including industry replacements for CFCs
such as HCFCs and HFCs.
Important Responsible
Refrigerant Practices
Trane believes that responsible refrigerant practices are
important to the environment, our customers, and the air
conditioning industry. All technicians who handle
refrigerants must be certified. The Federal Clean Air Act
(Section 608) sets forth the requirements for handling,
reclaiming, recovering and recycling of certain
refrigerants and the equipment that is used in these
service procedures. In addition, some states or
municipalities may have additional requirements that
must also be adhered to for responsible management of
refrigerants. Know the applicable laws and follow them.
The three types of advisories are defined as follows:
WARNING Indicates a potentially hazardous
situation which, if not avoided, could
result in death or serious injury.
CAUTIONsIndicates a potentially hazardous
situation which, if not avoided, could
result in minor or moderate injury. It
could also be used to alert against
unsafe practices.
NOTICE Indicates a situation that could result in
equipment or property-damage only
accidents.
WARNING
Proper Field Wiring and Grounding
Required!
Failure to follow code could result in death or serious
injury. All field wiring MUST be performed by qualified
personnel. Improperly installed and grounded field
wiring poses FIRE and ELECTROCUTION hazards. To
avoid these hazards, you MUST follow requirements for
field wiring installation and grounding as described in
NEC and your local/state electrical codes.
WARNING
Personal Protective Equipment (PPE)
Required!
Installing/servicing this unit could result in exposure to
electrical, mechanical and chemical hazards.
• Before installing/servicing this unit, technicians
MUST put on all PPE required for the work being
undertaken (Examples; cut resistant gloves/sleeves,
butyl gloves, safety glasses, hard hat/bump cap, fall
protection, electrical PPE and arc flash clothing).
ALWAYS refer to appropriate Material Safety Data
Sheets (MSDS)/Safety Data Sheets (SDS) and OSHA
guidelines for proper PPE.
• When working with or around hazardous chemicals,
ALWAYS refer to the appropriate MSDS/SDS and
OSHA/GHS (Global Harmonized System of
Classification and Labelling of Chemicals) guidelines
for information on allowable personal exposure
levels, proper respiratory protection and handling
instructions.
• If there is a risk of energized electrical contact, arc, or
flash, technicians MUST put on all PPE in accordance
with OSHA, NFPA 70E, or other country-specific
requirements for arc flash protection, PRIOR to
servicing the unit. NEVER PERFORM ANY
SWITCHING, DISCONNECTING, OR VOLTAGE
TESTING WITHOUT PROPER ELECTRICAL PPE AND
ARC FLASH CLOTHING. ENSURE ELECTRICAL
METERS AND EQUIPMENT ARE PROPERLY RATED
FOR INTENDED VOLTAGE.
Failure to follow instructions could result in death or
serious injury.

Introduction
RT-SVX51B-EN 3
Overview of Manual
Note: One copy of this document ships inside the control
panel of each unit and is customer property. It must
be retained by the unit’s maintenance personnel.
This booklet describes proper installation, operation, and
maintenance procedures for air cooled systems.
By carefully reviewing the information within this manual
and following the instructions, the risk of improper
operation and/or component damage will be minimized.
It is important that periodic maintenance be performed to
help assure trouble free operation. A maintenance
schedule is provided at the end of this manual.
Should equipment failure occur, contact a qualified
service organization with qualified, experienced HVAC
technicians to properly diagnose and repair this
equipment.
Copyright
This document and the information in it are the property of
Trane, and may not be used or reproduced in whole or in
part without written permission. Trane reserves the right
to revise this publication at any time, and to make changes
to its content without obligation to notify any person of
such revision or change.
Trademarks
All trademarks referenced in this document are the
trademarks of their respective owners.
Revision Summary
RT-SVX51B-EN (30 Dec 2014)
• Updated Warranty section
WARNING
Proper Field Wiring and Grounding
Required!
All field wiring MUST be performed by qualified
personnel. Improperly installed and grounded field
wiring poses FIRE and ELECTROCUTION hazards. To
avoid these hazards, you MUST follow requirements for
field wiring installation and grounding as described in
NEC and your local/state electrical codes. Failure to
follow code could result in death or serious injury.
NOTICE:
Water Damage!
Non-factory penetrations through the base of this unit
are not allowed. Any penetration in the base of the unit
may affect the water tight integrity of the unit and lead
to water leaks into the conditioned space. Failure to
follow instructions could result in equipment and
property damage.

4RT-SVX51B-EN
Table of Contents
Model Number Description . . . . . . . . . . . . . . . 5
General Information . . . . . . . . . . . . . . . . . . . . . 6
Unit Inspection . . . . . . . . . . . . . . . . . . . . . . . . 6
Precautionary Measures . . . . . . . . . . . . . . . . 6
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Unit Description . . . . . . . . . . . . . . . . . . . . . . . 6
System Input Devices & Functions . . . . . . . 7
Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Initiation of Operating Modes - JADE Control-
ler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . 9
Unit Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Rigging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Unit Foundation . . . . . . . . . . . . . . . . . . . . . . 16
General Unit Requirements . . . . . . . . . . . . 16
Main Unit Power . . . . . . . . . . . . . . . . . . . . . 19
Factory-Mounted Unit Options . . . . . . . . . . . 24
Unit Disconnect (FIYUDC) . . . . . . . . . . . . . . 24
Through the Base Gas Utility Option . . . . 25
Pre Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Verifying Proper Air Flow (Units with Belt
Drive Indoor Fan) . . . . . . . . . . . . . . . . . . . . . 26
Electromechanical Controls
Test Procedure . . . . . . . . . . . . . . . . . . . . . . . 26
Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Standard Economizer Start-Up . . . . . . . . . 27
LLE Controls Test Procedure . . . . . . . . . . . 27
Compressor Start-Up . . . . . . . . . . . . . . . . . 27
Heating Start-Up . . . . . . . . . . . . . . . . . . . . . 28
Final System Set Up . . . . . . . . . . . . . . . . . . 28
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Fan Belt Adjustment—Belt Drive Units . . 29
Monthly Maintenance . . . . . . . . . . . . . . . . . 30
Final Process . . . . . . . . . . . . . . . . . . . . . . . . . 31
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . 32
Standard Troubleshooting . . . . . . . . . . . . . 32
Low Leak Economizer
(LLE) Troubleshooting . . . . . . . . . . . . . . . . . 32
Resetting Cooling and Heating Lockouts . .33
Unit Economizer Control (ECA) . . . . . . . . . .33
Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . .34
Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Central Air Conditioner . . . . . . . . . . . . . . . . .35

RT-SVX51B-EN 5
Model Number Description
Digit 1 — Unit Type
G = Packaged Gas/Electric
Digit 2 — Efficiency
A = ASHRAE 90.1 - 2010
Digit 3 — Airflow Configuration
C = Convertible
D = Downflow Only4
Digit 4, 5, 6 — Nominal Gross
Cooling Capacity (MBh)
180 = 15 Tons
210 = 17½ Tons
240 = 20 Tons
300 = 25 Tons
Digit 7 — Major Design
Sequence
A
Digit 8 — Voltage Selection
3 = 208-230/60/3
4 = 460/60/3
W = 575/60/3
Digit 9 — Unit Controls
E = Electromechanical
Digit 10 — Heating Capacity
H = Gas Heat - High4
L=GasHeat-Low
M= GasHeat-Medium
X = Gas Heat - SS Ht Ex - Low
Y = Gas Heat - SS Ht Ex - Medium
Z = Gas Heat - SS Ht Ex - High4
Digit 11 — Minor Design
Sequence
Digit 12, 13 — Service Sequence
00 = None
Digit 14 — Fresh Air Selection3
0=NoFreshAir
A = Manual Outside Air Damper
0-25%
B = Motorized Outside Air Damper
0-50%
C = Economizer, Dry Bulb 0-100%
without Barometric Relief5
D = Economizer, Dry Bulb 0-100%
with Barometric Relief1,5
E = Economizer, Reference Enthalpy
0-100% without Barometric
Relief5
F = Economizer, Reference Enthalpy
0-100% with Barometric Relief1,5
G = Economizer, Comparative
Enthalpy 0-100% without
Barometric Relief5
H = Economizer, Comparative
Enthalpy 0-100% with Barometric
Relief1,5
GAC 180 A 3 E H A 00
123 456 7 8 9 10 11 1213
J = Low Leak Economizer, Dry Bulb
w/o Barometric Relief5
L = Low Leak Economizer, Reference
Enthalpy w/o Barometric Relief5
N = Low Leak Economizer,
Comparative Enthalpy w/o
Barometric Relief5
Digit 15 — Supply Fan/Drive
Type/Motor
0=StandardMotor
1 = Oversized Motor
7 = Multi-Speed Standard Motor
9 = Multi-Speed Oversized Motor
Digit 17 — Condenser Coil
Protection
0 = Standard Coil
4 = CompleteCoat™ Condenser Coil
Digit 18 — Through The Base
Provisions
0 = No Through The Base Provisions
A = Through The Base Electric
B = Through-the-Base Gas
C = Through-the-Base Electric/Gas
D = Through-the-Base Access
Digit 19 — Disconnect Switch
0 = No Disconnect
1 = Unit Mounted Non-Fused
Disconnect Switch2
Digit 25 - System Monitoring
Controls
0 = No Monitoring Controls
A = Condensate Drain Pan Overflow
Switch
Digit 26
B = Economizer Fault Detection
and Diagnostics (FDD)6
Model Number Notes
1. Some field set up required.
2. Must be ordered with Through-
the-Base Electrical option.
3. All Factory Installed Options are
Built-to-Order. Check order
services for estimated production
cycle.
4. High heat is available on
downflow units only.
5. Factory installed economizers
only available in downflow
configuration.
6. Fault Detection and Diagnostics
(FDD) is available on Low Leak
Economizers only.
Model Number Description

6RT-SVX51B-EN
General Information
Unit Inspection
As soon as the unit arrives at the job site:
• Verify that the nameplate data matches the data on the
sales order and bill of lading (including electrical data).
• Verify that the power supply complies with the unit
nameplate specifications.
• Visually inspect the exterior of the unit, including the
roof, for signs of shipping damage.
• Visually inspect the internal components for shipping
damage as soon as possible after delivery and before
it is stored. Do not walk on the sheet metal base pans.
• If concealed damage is discovered, notify the carrier’s
terminal of damage immediately by phone and by
mail. Concealed damage must be reported within 15
days.
– Request an immediate joint inspection of the
damage by the carrier and the consignee.
– Do not remove damaged material from the
receiving location.
– Take photos of the damage, if possible. The owner
must provide reasonable evidence that the damage
did not occur after delivery.
• Notify the appropriate sales representative before
installing or repairing a damaged unit.
Precautionary Measures
• Avoid breathing fiberglass dust.
• Use a NIOSH approved dust/mist respirator.
• Avoid contact with the skin or eyes. Wear long-sleeved,
loose-fitting clothing, gloves, and eye protection.
• Wash clothes separately from other clothing: rinse
washer thoroughly.
• Operations such as sawing, blowing, tear-out, and
spraying may generate fiber concentrations requiring
additional respiratory protection. Use the appropriate
NIOSH approved respiration in these situations.
First Aid Measures
• Eye Contact - Flush eyes with water to remove dust. If
symptoms persist, seek medical attention.
• Skin Contact - Wash affected areas gently with soap
and warm water after handling.
Storage
Take precautions to prevent condensate from forming
inside the unit’s electrical compartments and motors if:
• The unit is stored before it is installed; or,
• The unit is set on the roof curb, and temporary heat is
provided in the building. Isolate all side panel service
entrances and base pan openings (e.g., conduit holes,
S/A and R/ A openings, and flue openings) from the
ambient air until the unit is ready for start-up.
Note: Do not use the unit’s heater for temporary heat
without first completing the start-up procedure
detailed under “Start Up,” p. 27.
The manufacturer will not assume any responsibility for
equipment damage resulting from condensate
accumulation on the unit’s electrical and/or mechanical
components.
Unit Description
Before shipment, each unit is leak tested, dehydrated,
charged with refrigerant and compressor oil, and run
tested for proper control operation.
Direct-drive, vertical discharge condenser fans are
provided with built-in thermal overload protection.
The stages of capacity control for these units are achieved
by starting the Economizer Control Actuator (ECA).
Economizer Control Actuator
Electromechanical Control
The ECA monitors the mixed air temperature, return air
temperature, minimum position setpoint (local or
remote), power exhaust setpoint, CO2setpoint, CO2, and
ambient dry bulb/ enthalpy sensor or comparative
humidity (return air humidity against ambient humidity)
sensors, if selected, to control dampers to an accuracy of
±5 percent of stroke. The actuator is spring returned to the
closed position any time that power is lost to the unit. It is
capable of delivering up to 25 in·lb of torque and is
powered by 24 Vac.
WARNING
Fiberglass Wool!
Product contains fiberglass wool. Disturbing the
insulation in this product during installation,
maintenance or repair will expose you to airborne
particles of glass wool fibers and ceramic fibers known
to the state of California to cause cancer through
inhalation. You MUST wear all necessary Personal
Protective Equipment (PPE) including gloves, eye
protection, a NIOSH approved dust/mist respirator, long
sleeves and pants when working with products
containing fiberglass wool. Exposition to glass wool
fibers without all necessary PPE equipment could result
in cancer, respiratory, skin or eye irritation, which could
result in death or serious injury.

General Information
RT-SVX51B-EN 7
JADE Economizer Control (For Low Leak
Economizer (LLE) Only)
The JADE controller is a standalone economizer controller
that provides outdoor air dry-bulb economizer control
standard. With optional Sylk Bus sensors, the controller
can provide comparative or reference enthalpy control.
Dampers are controlled to an accuracy of ±3.2 percent of
stroke. The actuator is spring returned to the closed
position any time that power is lost to the actuator. It is
capable of delivering up to 88 in·lb of torque and is
powered by 24 Vac.
System Input Devices &
Functions
The unit must have a thermostat input in order to operate.
The descriptions of the following basic input devices used
within the unit are to acquaint the operator with their
function as they interface with the various features.
Refer to the unit’s electrical schematic for the specific
device connections. The following controls are available
from the factory for field installation.
Drain Pan Condensate Overflow Switch
(Optional)
This input incorporates the Condensate Overflow Switch
(COF) mounted on the drain pan. When the condensate
level reaches the trip point, the COF relay energizes and
opens the 24VAC control circuit, disabling the unit. A delay
timer prevents the unit from staring for 3 minutes.
Phase Monitor
The Phase Monitor is a three-phase line monitor module
that protects against phase loss, phase reversal and phase
unbalance. It is intended to protect compressors from
reverse rotation. It has an operating input voltage range of
190–600 Vac, and LED indicators for ON and FAULT. There
are no field adjustments and the module will automatically
reset from a fault condition.
Discharge Line Thermostat Control
The high pressure controls and discharge line thermostats
are wired in series between the thermostat signal and the
compressor contactors. If the high pressure control switch
or the discharge line thermostat open, the 24VAC signal
from the thermostat is interrupted and the compressor is
disabled. There is no automatic lockout.
Power Exhaust Control (Optional)
The power exhaust fan is started whenever the position of
the economizer dampers meets or exceed the power
exhaust setpoint when the indoor fan is on.
The setpoint panel is located in the return air section and
is factory set at 25% (50% for LLE).
To configure the LLE controller, set EXH1 SET (or EXH1 L
& EXH1 H with two-speed fan) in the SETPOINTS menu. 2-
speed fan mode requires AUX2 I set as W.
Evaporator Frost Control (Optional)
This input incorporates the Frostat™ control (FOS)
mounted in the indoor coil and can be activated by closing
a field supplied contact installed in parallel with the FOS.
If this circuit is open before the compressor is started, the
compressor will not be allowed to operate. Anytime this
circuit is opened for 5 continuous seconds during
compressor operation, the compressor for that circuit is
immediately turned “Off”. The compressor will not be
allowed to restart for a minimum of 3 minutes should the
FOS close.
Sensors
High Temperature Sensor (BAYFRST003*)
This sensor connects to the Emergency Stop Input on the
LTB and provides high limit “shutdown” of the unit. The
sensor is used to detect high temperatures due to fire in
the air conditioning or ventilation ducts. The sensor is
designed to mount directly to the sheet metal duct. Each kit
contains two sensors. The return air duct sensor
(X1310004001) is set to open at 135°F.
The supply air duct sensor (X1310004002) is set to open at
240°F. The control can be reset after the temperature has
been lowered approximately 25°F below the cutout
setpoint.
Thermostat (TCONT802AS32DA)
This thermostat is a multi-stage 3 heat/2 cool, auto-
changeover digital display thermostat. It is a
programmable thermostat, and a 7-day programmable
stat with night setback shall be available. In addition, it is
wall mounted.
Thermostat (TCONT402AN32DA)
This thermostat is a multi-stage 3 heat/2 cool, auto
changeover digital display thermostat. It is a non-
programmable, wall-mounted thermostat, and it can be
used for economizer operation.
CO2Sensor
This optional sensor can be added for Demand Control
Ventilation (DCV) functionality.
On units with a low leak economizer, configure the JADE
controller by setting the following parameters:
SETPOINTS Menu:
DCV SET = desired CO2ppm to start DCV
VENTMAX = desired maximum position w/DCV &
occupied status (2-speed applications require LO & HI
settings)

General Information
8RT-SVX51B-EN
VENTMIN = desired minimum position w/DCV & occupied
status (2-speed applications require LO & HI settings)
ADVANCED SETUP Menu:
CO2 ZERO = set to detector's start level
CO2 SPAN = detector's max level minus start level
Attach the sensor to the CO2and "R" terminals (at
customer connections).
Note: When using any 0-10 Vdc CO2sensor with the JADE
you will need to set CO2 ZERO to 400 ppm and the
CO2 SPAN to 1600 ppm in the ADVANCED SETUP
menu.
Occupancy Sensor
A customer-supplied occupancy sensor can also be added
to provide damper control based on occupied/unoccupied
conditions.
Low Leak Economizer Units
To configure the JADE controller, set:
SYSTEM SETUP menu: OCC = INPUT
Attach the occupancy sensor to the OCC SENSOR wire and
"R" terminal (at customer connections). The occupancy
sensor must utilize a normally open contact for proper
operation.
If an occupancy sensor is not used, another option to
controlling occupied and unoccupied status is to use the
'G' input (fan is running). Connect the G input to the OCC
SENSOR wire (at customer connections). The controller
will then operate in the occupied mode every time the
indoor fan is running.
Initiation of Operating Modes -
JADE Controller
The JADE controller is able to initiate the following modes:
Compressor, Economizer, Fans, Heating System, and
Cooling System.
The Compressor mode is initiated by either the OAT going
above the DRYBLB SET setting or by the thermostat
initiating a call to cool when the damper is at 100% open.
The Economizer mode is controlled by the MAT getting
above the MAT SET setting while the OAT is below the
DRYBLB SET setting. While the fans are not controlled by
the controller, the Fan mode is dependent on what state
the system is in (OCC or Y1 states will cause the damper to
go to a LOW fan speed damper setting, while Y2 or W
states will cause the controller to open the damper to the
HIGH fan speed damper setting). The Heating System
mode requires an input to the AUX2-1 terminal from the
thermostat, and the Cooling System mode requires an
input to the Y2 IN and/or the Y1 IN terminals from the
thermostat.

RT-SVX51B-EN 9
Dimensional Data
Figure 1, p. 12 illustrates the minimum operating and
service clearances for either a single or multiple unit
installation. These clearances are the minimum distances
necessary to assure adequate serviceability, cataloged
unit capacity, and peak operating efficiency.
Providing less than the recommended clearances may
result in condenser coil starvation, “short-circuiting” of
exhaust and economizer airflows, or recirculation of hot
condenser air.
Figure 1. Typical installation clearance for single and multiple unit applications
5' 8"
5' 0"

Dimensional Data
10 RT-SVX51B-EN
Figure 2. Gas/electric units — overview
-
Figure 3. Gas/electric units — front & side views — 15–25 tons standard efficiency

Dimensional Data
RT-SVX51B-EN 11
Figure 4. Gas/electric units — plan view — 15–25 tons standard efficiency
82 1/4"
Figure 5. Foundation units — back view (horizontal configuration) — 15–25 tons standard efficiency

Dimensional Data
12 RT-SVX51B-EN
Figure 6. Roof curb —15–25 tons standard efficiency
Figure 7. Downflow duct connections—field fabricated 15–25 tons standard efficiency
9
1”
25.4 MM
CURB FLANGE
LONG SIDES
SHORT SIDES
Notes:
•Duct flanges mount 7-7/16” down inside the
curb on the 1-1½” curb flanges.
•Roofcurb is intended for downflow use only.

Dimensional Data
RT-SVX51B-EN 13
Figure 8. Downflow unit clearance — 15–25 tons standard efficiency
Figure 9. Barometric relief and economizer— 15–25 tons standard efficiency
MOTORIZED DAMPER
BAROMETRIC RELIEF IS FOR USE WITH A DOWNFLOW ECONOMIZER ONLY
(
FOR LOW LEAK)
( FOR LOW LEAK)

Dimensional Data
14 RT-SVX51B-EN
Figure 10. Manual damper — 15–25 tons standard efficiency

RT-SVX51B-EN 15
Unit Weights
Rigging
Refer to Figure 12 and Ta b l e 1 for typical unit operating
weights rigging before proceeding.
1. Remove the shipping crate from around the unit. Do
not remove the crating from the top of the unit.
2. Rig the unit as shown in Figure 12, p. 15. Attach
adequate strength lifting slings to all four lifting
brackets in the unit base rail. Do not use cables, chains,
or slings except as shown.
3. Install a lifting bar, as shown in Figure 12, to protect the
unit and to facilitate a uniform lift. The minimum
distance between the lifting hook and the top of the
unit should be 7 feet.
4. Test-lift the unit to ensure it is properly rigged and
balanced, make any necessary rigging adjustments.
5. Lift the unit and position it into place.
6. Downflow units; align the base rail of the unit with the
curb rail while lowering the unit onto the curb. Make
sure that the gasket on the curb is not damaged while
positioning the unit.
Table 1. Maximum unit & corner weights (lb) and center of gravity dimensions (in.)
Tons Unit Model No.
Weights (lb)(a), (b) Corner Weights(c) Center of Gravity (in.)
Shipping Net A B C D Length Width
15 GAC180A 2183 1864 626 439 371 427 54” 37”
17½ GAC210A 2238 1918 636 455 392 436 55” 38”
20 GAC240A 2327 2007 690 475 391 451 54” 37”
25 GAC300A 2327 2058 723 493 380 455 53” 35”
(a)Weights are approximate. Horizontal and downflow unit and corner weights may vary slightly.
(b)Weights do not include additional factory or field installed options/accessories.
(c)Corner weights are given for information only. 15–25 ton models must be supported continuously by a curb or equivalent frame support.
Figure 11. Corner weights
WARNING
Heavy Objects!
Ensure that all the lifting equipment used is properly
rated for the weight of the unit being lifted. Each of the
cables (chains or slings), hooks, and shackles used to
lift the unit must be capable of supporting the entire
weight of the unit. Lifting cables (chains or slings) may
not be of the same length. Adjust as necessary for even
unit lift. Other lifting arrangements could cause
equipment or property damage. Failure to follow
instructions above or properly lift unit could result in
unit dropping and possibly crushing operator/
technician which could result in death or serious injury.
WARNING
Improper Unit Lift!
Test lift unit approximately 24 inches to verify proper
center of gravity lift point. To avoid dropping of unit,
reposition lifting point if unit is not level. Failure to
properly lift unit could result in unit dropping and
possibly crushing operator/technician which could
result in death or serious injury and possible equipment
or property-only damage.
Figure 12. Rigging and center of gravity data

16 RT-SVX51B-EN
Installation
Unit Foundation
Horizontal Units
Notes:
•For complete step by step instructions on how to install
a Horizontal Conversion Kit, please refer to ACC-
SVN159*-EN.
•For units with optional Condensate Overflow Switch
(COF), the switch will not work properly if unit is not
level or slightly sloped toward switch.
•To assure proper condensate flow during operation the
unit and the curb must be level.
If the unit is installed at ground level, elevate it above the
snow line. Provide concrete footings at each support
location with a “full perimeter” support structure or a slab
foundation for support. Refer to Ta b l e 1 , p . 15 for the unit’s
operating and point loading weights when constructing a
footing foundation.
If anchoring is required, anchor the unit to the slab using
hold down bolts or isolators. Isolators should be installed
to minimize the transmission of vibrations into the
building.
For rooftop applications, if anchoring is required, anchor
the unit to the roof with hold-down bolts or isolators.
Check with a roofing contractor for proper waterproofing
procedures.
Ductwork
Elbows with turning vanes or splitters are recommended
to minimize air noise due to turbulence and to reduce static
pressure.
When attaching the ductwork to the unit, provide a water-
tight flexible connector at the unit to prevent operating
sounds from transmitting through the ductwork.
All outdoor ductwork between the unit and the structure
should be weather proofed after installation is completed.
Note: For sound consideration, cut only the holes in the
roof deck for the ductwork penetrations. Do not cut
out the entire roof deck within the curb perimeter.
If a Curb Accessory Kit is not used:
a. The ductwork can be attached directly to the
factory-provided flanges around the unit’s supply
and return air openings. Be sure to use flexible duct
connections at the unit.
b. For “built-up” curbs supplied by others, gaskets
must be installed around the curb perimeter flange
and the supply and return air opening flanges.
General Unit Requirements
The checklist listed below is a summary of the steps
required to successfully install a commercial unit. This
checklist is intended to acquaint the installing personnel
with what is required in the installation process. It does not
replace the detailed instructions called out in the
applicable sections of this manual.
• Check the unit for shipping damage and material
shortage; file a freight claim and notify appropriate
sales representative.
• Verify correct model, options and voltage from
nameplate.
• Verify that the installation location of the unit will
provide the required clearance for proper operation.
WARNING
Risk of Roof Collapsing!
Confirm with a structural engineer that the roof
structure is strong enough to support the combined
weight of the roofcurb and the unit. Refer to “Unit
Weights,” p. 15 for typical unit and curb weights. Failure
to ensure proper structural roof support could cause the
roof to collapse, which could result in death or serious
injury and property damage.
NOTICE:
Water Damage!
Non-factory penetrations through the base of this unit
are not allowed. Any penetration in the base of the unit
may affect the water tight integrity of the unit and lead
to water leaks into the conditioned space. Failure to
follow instructions could result in equipment and
property damage.
NOTICE:
Potential Overheating Condition!
Do not convert high heat units to horizontal airflow
configuration. These models are designed for down
flow applications only. Failure to follow instructions
could result in equipment damage.
WARNING
Proper Field Wiring and Grounding
Required!
All field wiring MUST be performed by qualified
personnel. Improperly installed and grounded field
wiring poses FIRE and ELECTROCUTION hazards. To
avoid these hazards, you MUST follow requirements for
field wiring installation and grounding as described in
NEC and your local/state electrical codes. Failure to
follow code could result in death or serious injury.

Installation
RT-SVX51B-EN 17
• Assemble and install the roof curb (if applicable). Refer
to the latest edition of the curb installers guide that
ships with each curb kit.
• Fabricate and install ductwork; secure ductwork to
curb.
• Rigging the unit.
• Set the unit onto the curb; check for levelness.
• Ensure unit-to-curb seal is tight and without buckles or
cracks.
• Install and connect a condensate drain line to the
evaporator drain connection.
Factory Installed Economizer
• Ensure the economizer has been pulled out into the
operating position. Refer to the standard or low leak
economizer Installation Instructions for proper
position and setup.
• Install all access panels.
Controller Wiring Schematic - LLE
For additional information, go to the Installation
Instructions ACC-SVN178*-EN.
Main Electrical Power Requirements
• Verify that the power supply complies with the unit
nameplate specifications.
• Inspect all control panel components; tighten any
loose connections.
• Connect properly sized and protected power supply
wiring to a field-supplied/ installed disconnect switch
and to the main power terminal block (HTB1) in the unit
control panel.
• Install proper grounding wires to an earth ground.
Note: All field-installed wiring must comply with NEC
and applicable local codes.
Figure 13. Wiring schematic - low leak economizer

Installation
18 RT-SVX51B-EN
External Vent Hood Installation
1. Remove and discard the cover plate located on the gas
heat panel.
Important:
•Make sure you read the label located on the cover plate
before you discard it.
•Do not discard the fastening screws! They will be
needed to install the vent hood.
2. Locate the vent hood behind the panel, on the left side
of the burner assembly.
3. Install the vent hood on the gas heat panel using the
screws removed in Step 1. Make sure it is properly
secured on to the panel.
TCO1 Instructions
Important: These instructions do not apply to high heat
units (Digit 10 of the model number = H or Z)
as they are designed for down flow
applications only! See “Potential
Overheating Condition!” on page 16.
If the unit is installed in horizontal configuration, the
factory installed limit control TCO1 must be replaced with
the TCO1 for horizontal applications shipped in the heater
compartment.
Replace TCO1 following instructions below.
1. Remove the heat section access panel.
2. Remove TCO1 from shipping location - attached to the
gas manifold vertical leg - as shown below:
3. Replace and discard the existing TCO1 originally
installed at the factory for down flow operation with
the TCO1 from Step 2 for horizontal operation.
WARNING
Hazardous Voltage!
Disconnect all electric power, including remote
disconnects before servicing. Follow proper lockout/
tagout procedures to ensure the power can not be
inadvertently energized. Failure to disconnect power
before servicing could result in death or serious injury.
Figure 14. Discard cover plate
Figure 15. Vent hood shipping location
Figure 16. Vent hood installation
Figure 17. TCO1 shipping locations
Low heat option
TCO1 limit location
Medium heat option
TCO1 limit location

Installation
RT-SVX51B-EN 19
4. Reinstall the heat section access panel.
Condensate Drain Configuration
An evaporator condensate drain connection is provided
on each unit. Refer to “Unit Dimensions,” p. 12 for the
appropriate drain location.
Note: Use 1" PVC pipe to connect to the drain pan outlet
provided in the unit. This is a slip fit joint (no
threads) and can be sealed using PVC Cement or
other suitable adhesive.
A condensate trap must be installed at the unit due to the
drain connection being on the “negative pressure” side of
the fan.
A condensate drain line must be connected to the P-Trap.
Pitch the drain lines at least ½-inch for every 10 feet of
horizontal run to assure proper condensate flow. Do not
allow the horizontal run to sag causing a possible double-
trap condition which could result in condensate backup
due to “air lock”.
Filter Installation
Each unit ships with 2-inch filters installed. The quantity of
filters is determined by unit size. Access to the filters is
obtained by removing the filter access panel.
Refer to the unit Service Facts (shipped with each unit) for
filter requirements.
Note: Do not operate the unit without filters.
Field Installed Power Wiring
An overall dimensional layout for the standard field
installed wiring entrance into the unit is illustrated in “Unit
Dimensions,” p. 12. To insure that the unit’s supply power
wiring is properly sized and installed, follow the guidelines
outlined below.
Note: All field installed wiring must conform to NEC
guidelines as well as state and Local codes.
Verify that the power supply available is compatible with
the unit’s nameplate ratings. The available supply power
must be within 10 percent of the rated voltage stamped on
the nameplate. Use only copper conductors to connect the
power supply to the unit.
Note: If the unit is not equipped with an optional factory
installed nonfused disconnect switch or circuit
breaker, a field supplied disconnect switch must be
installed at or near the unit in accordance with the
National Electrical Code (NEC latest edition).
Main Unit Power
Standard Wiring
The electrical service must be protected from over current
and short circuit conditions in accordance with NEC
requirements.
Protection devices must be sized according to the
electrical data on the nameplate.
• If the unit is not equipped with an optional factory
installed nonfused disconnect switch, a field supplied
disconnect switch must be installed at or near the unit
in accordance with the National Electrical Code (NEC
latest edition).
• Location of the applicable electrical service entrance is
illustrated in “Unit Dimensions,” p. 12. Complete the
unit’s power wiring connections onto either; the main
terminal block HTB1 inside the unit control panel, the
factory mounted nonfused disconnect switch (UCD), or
the electric heat terminal block. Refer to the customer
connection diagram that shipped with the unit for
specific termination points.
• Provide proper grounding for the unit in accordance
with local and national codes.
Figure 18. Factory installed down flow TCO1 limit
location NOTICE:
Use Copper Conductors Only!
Unit terminals are not designed to accept other types of
conductors. Failure to use copper conductors could
result in equipment damage.
WARNING
Proper Field Wiring and Grounding
Required!
All field wiring MUST be performed by qualified
personnel. Improperly installed and grounded field
wiring poses FIRE and ELECTROCUTION hazards. To
avoid these hazards, you MUST follow requirements for
field wiring installation and grounding as described in
NEC and your local/state electrical codes. Failure to
follow code could result in death or serious injury.

Installation
20 RT-SVX51B-EN
Optional TBUE Wiring (Through the Base
Electrical Option)
• Location of the applicable electrical service is
illustrated below. Refer to the customer connection
diagram that is shipped with the unit for specific
termination points. The termination points, depending
on the customer option selected would be a factory
mounted nonfused disconnect switch (UDC).
• Provide proper grounding for the unit in accordance
with local and national codes.
Control Power Transformer
The 24-volt control power transformers are to be used only
with the accessories called out in this manual.
Transformers rated greater than 50 Vac are equipped with
internal circuit breakers. If a circuit breaker trips, turn “Off”
all power to the unit before attempting to reset it.
The transformer is located in the control panel. The circuit
breaker is located on the left side of the transformer and
can be reset by pressing in on the black reset button.
Controls using 24 Vac
Before installing any connecting wiring, refer to “Unit
Dimensions,” p. 12 for the electrical access locations
provided on the unit and Ta bl e 2 , p . 2 0 for AC conductor
sizing guidelines.
1. Use copper conductors unless otherwise specified.
2. Ensure that the AC control wiring between the controls
and the unit’s termination point does not exceed three
(3) ohms/conductor for the length of the run.
Note: Resistance in excess of 3 ohms per conductor
could cause component failure due to insufficient
AC voltage supply.
3. Be sure to check all loads and conductors for grounds,
shorts, and mis-wiring.
4. Do not run the AC low voltage wiring in the same
conduit with the high voltage power wiring.
5. Route low voltage wiring per illustrations on the next
page.
Figure 19. Through the base electrical option
NOTICE:
Use Copper Conductors Only!
Unit terminals are not designed to accept other types of
conductors. Failure to use copper conductors could
result in equipment damage.
Table 2. Electromechanical thermostat 24 Vac
conductors
Distance from Unit to
Control Recommended Wire Size
000–460 feet 18 gauge
000–140 m 0.75 mm2
461–732 feet 16 gauge
Figure 20. Conventional thermostat field wiring
diagram