Trane CeilAir CW Installation and operating instructions

CeilAir® CW and DX
Ceiling Mounted Precision Air Conditioners/
Air Handlers
3.5-35 kW / 60 Hz
Installation, Operation, and Maintenance
December 2020 AH-SVX008C-EN
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.

© 2020 Trane AH-SVX008C-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.
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.
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
and HCFCs such as saturated or unsaturated HFCs and
HCFCs.
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 according to local rules. For
the USA, 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.
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!
Failure to wear proper PPE for the job being undertaken
could result in death or serious injury. Technicians, in
order to protect themselves from potential electrical,
mechanical, and chemical hazards, MUST follow
precautions in this manual and on the tags, stickers,
and labels, as well as the instructions below:
• 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 Safety Data Sheets
(SDS) and OSHA guidelines for proper PPE.
• When working with or around hazardous chemicals,
ALWAYSrefertotheappropriateSDS andOSHA/GHS
(Global Harmonized System of Classification and
Labeling 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.

WARNING
Confined Space Hazards!
Failure to follow instructions below could result in
death or serious injury.
Do not work in confined spaces where refrigerant or
other hazardous, toxic or flammable gas may be
leaking. Refrigerant or other gases could displace
available oxygen to breathe, causing possible
asphyxiation or other serious health risks. Some gases
may be flammable and or explosive. If a leak in such
spaces is detected, evacuate the area immediately and
contact the proper rescue or response authority.
WARNING
Follow EHS Policies!
Failure to follow instructions below could result in
death or serious injury.
• All Trane personnel must follow the company’s
Environmental, Health and Safety (EHS) policies
when performing work such as hot work, electrical,
fall protection, lockout/tagout, refrigerant handling,
etc. Where local regulations are more stringent than
these policies, those regulations supersede these
policies.
• Non-Trane personnel should always follow local
regulations.
Introduction
AH-SVX008C-EN 3
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 History
Updated Model Number Descriptions chapter.

4AH-SVX008C-EN
Table of Contents
Model Number Descriptions . . . . . . . . . . . . . . 6
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Product Description . . . . . . . . . . . . . . . . . . . . 7
Control Devices . . . . . . . . . . . . . . . . . . . . . . . 7
Coil(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Blower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Temperature Sensor . . . . . . . . . . . . . . . . . 8
Optional Equipment . . . . . . . . . . . . . . . . . . . 8
Humidistat/Dehumidistat . . . . . . . . . . . . . . 8
Temperature/Humidity Sensor . . . . . . . . . 8
Heaters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Humidifier . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Condensate Pump . . . . . . . . . . . . . . . . . . . 9
Smoke Detector . . . . . . . . . . . . . . . . . . . . . 9
Firestat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Water Detector . . . . . . . . . . . . . . . . . . . . . . 9
Free-cooling Operation . . . . . . . . . . . . . . . . . 9
AWS Operation . . . . . . . . . . . . . . . . . . . . . . 10
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Receiving the Equipment . . . . . . . . . . . . . . 12
Site Preparation . . . . . . . . . . . . . . . . . . . . . . 12
Rigging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Indoor Equipment . . . . . . . . . . . . . . . . . . 13
Outdoor Equipment . . . . . . . . . . . . . . . . . 13
Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Optional Equipment . . . . . . . . . . . . . . . . . 15
Remote Sensors . . . . . . . . . . . . . . . . . . . . 15
Piping Connections . . . . . . . . . . . . . . . . . . . 17
Refrigerant . . . . . . . . . . . . . . . . . . . . . . . . 17
Condensate Drain Line . . . . . . . . . . . . . . . 19
Condensate Pump . . . . . . . . . . . . . . . . . . 20
Humidifier (Optional) . . . . . . . . . . . . . . . . 20
Utility Connections . . . . . . . . . . . . . . . . . . . 20
Main Power . . . . . . . . . . . . . . . . . . . . . . . . 20
Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
A-Tech 1.1 Programmable Thermostat . 22
A-Tech 1.2 Programmable Thermostat . .22
Air-Cooled Split Systems . . . . . . . . . . . . .22
Optional Equipment . . . . . . . . . . . . . . . . . .26
System Charging Procedures . . . . . . . . . . .27
Water/Glycol Systems . . . . . . . . . . . . . . . .27
Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
DX Unit Charging Requirements . . . . . . .27
Refrigerant Characteristics . . . . . . . . . . . . . .30
Pressure/Temperature Settings . . . . . . . .30
Saturated Refrigerant Pressure Tables . .31
System Settings and Adjustments . . . . . . .32
Low/High Pressure Limit Switch . . . . . . . .32
Head Pressure Controls-Air Cooled Systems
32
Blower Adjustment . . . . . . . . . . . . . . . . . .33
Commissioning, Operation and Decommis-
sioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Commissioning the Unit . . . . . . . . . . . . . . . .36
Commissioning Steps . . . . . . . . . . . . . . . .36
Operating the Unit . . . . . . . . . . . . . . . . . . .36
Start-up Procedure . . . . . . . . . . . . . . . . . . .36
Programming the Thermostat . . . . . . . . . . .37
A-Tech Controller . . . . . . . . . . . . . . . . . . . .37
Microprocessor Controller . . . . . . . . . . . .37
Decommissioning the Unit . . . . . . . . . . . . .37
Recovering Refrigerant . . . . . . . . . . . . . . .37
Labeling Decommissioned Equipment . .38
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Periodic General Maintenance . . . . . . . . . .39
A/C Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . .41
Field Service . . . . . . . . . . . . . . . . . . . . . . . . . .44
Leak Detection . . . . . . . . . . . . . . . . . . . . . .44
Leak Repair . . . . . . . . . . . . . . . . . . . . . . . . .44
Refrigerant Piping . . . . . . . . . . . . . . . . . . .44
General Common Repairs/Component Re-
placement . . . . . . . . . . . . . . . . . . . . . . . . . .44
Product Support . . . . . . . . . . . . . . . . . . . . . . .46
Factory Authorized Start Up/Warranty In-

Table of Contents
AH-SVX008C-EN 5
spection . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Technical Support . . . . . . . . . . . . . . . . . . 46
Obtaining Warranty Parts . . . . . . . . . . . . 46
Obtaining Spare/Replacement Parts . . . . 47
Appendix A TR-OHS Preventive Maintenance
Inspection Checklist . . . . . . . . . . . . . . . . . . . . . 48

6AH-SVX008C-EN
Model Number Descriptions
CeilAir® Overhead System
Digit 1, 2, 3, 4, 5 — System
TR-OHS = CeilAir® Overhead System

Digit 6, 7, 8 — Capacity MBH
012
018
024
032
040
048
060
072
084
120

Digit 9 — Configuration1
D( ) = Dual Circuit
H( ) = Horizontal
Discharge (“HSeries”)

Digit 10 — Model
AHU = Air Handling Unit
AR = Air-Cooled Remote (Split)
AS = Air-Cooled Self-Contained
C = Chilled Water System
G = Glycol-Cooled
W = Water Cooled

Digit 11, 12 — Options
AWS = Alternate Water Source
FC = Free Cooling
LP = Low Profile Configuration
SF = Same-Face Air Pattern
SP = Special Configuration
About Digits
Model numbers are comprised of
digits. Each digit, or set of digits,
defines the product model.
Example using model 
TR-OHS-040-H-G-FC:
• Overhead System 
(OHS, digits 1,2,3,4,5)
• 40,000 MBH Capacity (digits 6,7,8)
• Horizontal Discharge (digit 9)
• Glycol Cooled (digit 10)
• Optional Free Cooling 
(digits 11,12)
1Digit 9 not used with any single circuit selection.

AH-SVX008C-EN 7
Overview
General
Trane CeilAir overhead air conditioning systems (TR-OHS)
are constructed using the finest available materials/
components, state-of-the-art technology and quality
craftsmanship. The unit will provide years of trouble free
service if installed and maintained in accordance with this
manual. Damage to the unit from improper installation,
operation or maintenance is not covered by the warranty.
Due to advances in technology, components described
herein are subject to change without notice.
CeilAir TR-OHS systems are designed to be installed
indoors, unless otherwise noted on the equipment.
Propeller-type condensers, condensing units, drycoolers
and pump packages are designed for outdoor use.
Product Description
CeilAir TR-OHS systems are designed to be the most
versatile and flexible ceiling-mounted air conditioning
systems in the industry. The unit is available in air-cooled,
water-cooled, glycol-cooled and chilled-water
configurations. The cooling capacity in Btu/h will depend
on the unit size, which can range from 1 to 10 tons (3.5-35
kW), and can be either a single stage or dual stage unit.
In addition to cooling, other functional modes of opera-
tion include heating, humidification, dehumidification and
filtration to provide complete environmental control of a
conditioned space. The cabinet configuration is available
in a 2 ft x 4 ft frame for units ranging from 12,000 to 40,000
Btu/h (spot cooler or ducted) or a larger frame for units
ranging from 48,000 to 120,000 Btu/h (ducted only).
For ducted units, there are three configurations of airflow
patterns, dependent on unit: 90oright angle, straight
through and in/ out-same-face (see Figure 9, p. 14). Refer
to the installation drawing provided with the unit for the
type of cabinet configuration and for the layout
dimensions.
Control Devices
Control interfaces are typically remotely mounted to a wall
or control panel.
The default control device for TR-OHS units is the A-Tech
digital thermostat, which provides basic control of the
system. Slightly different wiring is used with the
thermostat in single- and dual-stage units, as shown in
Figure 16, p. 22. The single-stage version is the A-Tech 1.1.
The two-stage version is the A-Tech 1.2. An operating
manual for the thermostat is provided with the unit under
separate cover.
Figure 1. A-Tech digital thermostats
The advanced microprocessor controller is also available
for TR-OHS systems. This controller provides enhanced
features for more comprehensive control of the unit.
These features include full alarm system; input/output
monitoring status; full integrated control of heating,
cooling, humidification, and dehumidification and remote
communication with building management systems. An
operating manual for the controller is provided with the
unit under separate cover.
Figure 2. Microprocessor controller and display

Figure 3. All CeilAir TR-OHS-032-AR (access panels removed)
Overview
8AH-SVX008C-EN
Coil(s)
The cooling and optional hot water reheating coils are
aluminum finned/copper tube construction. The coils are
leak tested and cleaned before installation at the factory.
Blower
The unit is equipped with a centrifugal blower with
forward curved blades. The blower is contained in a
double-width, double-inlet housing. The blower is
dynamically and statically balanced to minimize vibration.
The blower motor is ODP industrial duty and utilizes
permanently lubricated ball bearings.
Smaller CeilAir units (models TR-OHS-012/040) use direct
drive blowers (except "H"-series models air configured for
horizontal discharge). Larger units (models TR-OHS-048/
120) and horizontal discharge units (models TR-OHS-012/
040-H), use a belt-driven blower. The belt-driven blower
motor is mounted on an adjustable base for belt
tensioning and is furnished with an adjustable pitch
sheave to adjust blower speed (see Figure 23, p. 33).
Temperature Sensor
As a standard for systems utilizing a wall mounted A-Tech
thermostat, the temperature sensor is built into the
thermostat for room air control. The sensor monitors the
room air conditions and provides input signal(s) to the
thermostat.
The thermostat manages the operation of the A/C unit
consistent with the setpoints entered.
As an option, the temperature sensor can be shipped loose
for field installation in the room to be conditioned. Refer to
the electrical drawing supplied with your unit for details
specific to your system.
Optional Equipment
Humidistat/Dehumidistat
As an option for systems employing an A-Tech 1.1 or A-
Tech 1.2 thermostat, a room mounted humidistat and/ or
dehumidistat can be shipped loose for field installation.
Each device has an adjustment dial on the front where the
operator selects the desired setpoint.
If an optional humidifier is selected, the humidistat is
included to control its operation. The humidistat controls
the humidifier's operation independently of the control
thermostat however, the blower must be on for the
humidifier to operate.
If the reheat option is selected, a dehumidistat is provided.
If room humidity rises above setpoint when the demand
for cooling is satisfied, the dehumidistat signals the
compressor to turn on, removing humidity. At the same
time, the heater(s) are turned on to offset the cooling
effect, thus maintaining the temperature of the space to be
conditioned. Refer to the electrical drawing supplied with
your unit for details specific to your system.
Temperature/Humidity Sensor
As a standard for systems that use the microprocessor
controller, a temperature/humidity (T/H) sensor is typically
factory mounted in the return air stream for room air
control. As an option, the T/H sensor may be shipped loose
for field installation. See“Remote Temperature/Humidity
Sensor,” p. 27 and the electrical drawing supplied with
your unit for details specific to your system.
Heaters
The TR-OHS unit may incorporate heaters for reheating
the supply air as required to offset the sensible cooling of
the system during the dehumidification cycle and for the

Overview
AH-SVX008C-EN 9
automatic heating mode. Electric resistance heating
elements are factory installed in the supply airstream to
heat the supply air. The heating elements are protected
with line fuses (manual and/or automatic), thermal fuse
links and over- temperature safety switches which
automatically reset.
As an option, hot water reheat may be selected for
automatic sensible reheating during the dehumidification
cycle. A hot water heating coil is factory installed in the
supply air stream. A valve is provided to control the flow
of hot water through the coil to maintain the correct reheat
temperature.
Hot gas reheat may be selected (for CeilAir DX units) for
automatic sensible reheating during the dehumidification
cycle. Hot compressor discharge gas is diverted from the
condenser to a hot gas heating coil mounted in the supply
airstream.
Humidifier
CeilAir systems may utilize an optional electrode steam
humidifier. The humidifier is factory installed inside the air
conditioner and includes fill and drain valves and
associated piping. Operation of the humidifier’s fill and
drain cycles is based on water conductivity and is
maintained by the humidifier controller. An operating
manual for the humidifier is provided with the unit under
separate cover. Refer to that manual for detailed
information about operating the humidifier.
Condensate Pump
An optional, factory-installed condensate pump may be
provided. The pump automatically eliminates condensate
and humidifier flush water (if applicable) from the drain
pan. Should an overflow occur, the pump overflow safety
switch triggers a contact signal to the controller that
indicates the alarm condition, and the controller
automatically shuts down the compressor and optional
humidifier until the condition is corrected. The blower(s)
will continue to operate. In an A-Tech system, the pump
safety switch is wired directly to the TR-OHS remote stop/
start terminals to cut power to the system.
Smoke Detector
A smoke detector may be mounted in the return airstream
to sense the presence of smoke and, when smoke is
detected, shut down the air conditioner, either via the
controller or in A-Tech systems via connection to the TR-
OHS remote stop/start terminals.
Firestat
A fire detector (firestat) may be mounted in the return
airstream to sense high return air temperature indicative
of a fire. The system shuts down, either through the
controller or, in an A-Tech system, via connection to the
TR-OHS remote stop/start terminals. Following activation,
the firestat must be manually reset using the reset button
on the firestat before restarting the unit.
Water Detector
As an option, Trane offers spot type or strip/cable type
water detectors. In units equipped with a microprocessor
controller, when water is detected the controller turns off
cooling and humidification, while the blower(s) continue
to operate. The unit will automatically restart when the
condition is corrected. In units equipped with an A-Tech
thermostat, the water detector is wired to the TR-OHS
remote stop/start terminals and power to the system is cut
when water is detected.
Free-cooling Operation
The free-cooling (FC) configuration illustrated in Figure 4,
p. 10 is available to minimize the use of compressor
operation during low ambient conditions for system
energy savings. An FC system utilizes a remote drycooler
to provide water/ glycol coolant to a free-cooling coil
positioned within a DX refrigerant system. If outdoor air
temperatures permit free- cooling operation (adjustable
user setpoint), the free-cooling mode is enabled to take
advantage of the low ambient conditions to provide
cooling with partial use or without the use of the system
compressor(s). Free-cooling provides an excellent
opportunity for reduced operational cost by reducing the
compressor operating hours. The free-cooling sequence is
enabled if the entering fluid temperature is below the user
adjustable free-cooling-enable setpoint and the return air
temperature rises to the free-cooling setpoint plus dead
band.
The drycooler pump activates and the 3-way control valve
directs chilled water/glycol coolant to the FC coil. The
outdoor fluid cooler is controlled by first switching the
leaving fluid control setpoint from typical DX heat
rejection to free-cooling control (adjustable setpoint,
ambient air) and by controlling the leaving fluid to its user-
adjustable setpoint. The free-cooling control valve opens
proportionally to the demand for cooling based on the
return air temperature deviation from setpoint.
If the return air temperature continues to rise, the free-
cooling valve position eventually reaches 100% open,
maximizing the flow of coolant through the free-cooling
coil. Continued operation in this position indicates the 
A/C unit is unable to lower the air temperature to the
desired setpoint in the free-cooling mode.

Figure 4. Free cooling
Overview
10 AH-SVX008C-EN
The compressor activates, if the DX cooling stage enable-
temperature setpoint has been reached or if the control
valve position reaches 100% open for 240 seconds (default
compressor-on time delay). The free-cooling circuit and
the compressor operate in parallel on dual-circuit units to
provide maximum cooling. The 3-way control valve
continually modulates the flow of coolant in response to
temperature with the compressor running.
The compressor cycles off based on the normal
compressor temperature cut-out settings once the
setpoint is maintained.
As the outside airtemperature increases above the
ambient air switch-over setting, the fluid cooler controls
cycle back to typical DX heat rejection allowing the leaving
fluid control setpoint to increase above the prevailing
ambient conditions. The indoor units inlet fluid
temperature sensor monitors the fluid temperature and
deactivates the free-cooling mode once the fluid
temperature increases above the user adjustable enable
setpoint. The compressor system becomes the primary
cooling source and will activate if the return air
temperature increases above the setpoint.
AWS Operation
The AWS (Alternate Water Source) configuration
illustrated in Figure 5 utilizes an independent chilled water
source to provide coolant to an AWS cooling coil in the 
A/C unit. If AWS cooling is unable to handle the load, the
separate DX refrigeration circuit can be utilized to assist.
Similar to FC operation (see “Free-cooling Operation,”
p. 9), when return air temperature rises to the AWS cut-in
temperature setpoint and if the chilled water inlet
temperature is 55 oF or less (adjustable), AWS cooling
activates (the AWS control valve opens) and remains on
while the activation conditions exist.

Figure 5. Alternate water source
Overview
AH-SVX008C-EN 11
If the return air temperature rises to the compressor cut-in
setpoint or if the AWS control valve reaches 100% open for
240 seconds (default compressor-on time delay), the
compressor turns on and operates in parallel with AWS
cooling. The compressor runs until the normal
compressor cut-out setpoint temperature is reached
provided the minimum run time expires.
If the chilled water inlettemperature rises above 55oF, AWS
cooling turns off (the control valve closes). When the DX
cooling stage-enable temperature setpoint is reached, the
compressor turns on and becomes the primary source of
cooling.
In the event of loss of water flow during AWS operation,
the AWS control valve is closed and the compressor
system becomes the primary cooling source. It will
activate if the return air temperature increases above the
setpoint.

12 AH-SVX008C-EN
Installation
Receiving the Equipment
Your CeilAir TR-OHS system has been tested and
inspected prior to shipment. To ensure the equipment is
received in excellent condition, visually inspect the
equipment immediately upon delivery. Carefully remove
the shipping container and all protective packaging.
Remove the access panels and thoroughly inspect the unit
interior for any signs of transit-incurred damage. If there is
shipping damage, it must be noted on the freight carrier’s
delivery forms before signing for the equipment. Any
freight claims must be done through the freight carrier.
Trane ships all equipment Factory FOB. Trane can assist in
the claim filing process with the freight carrier. Should any
damage be present, notify Trane Product Support prior to
attempting any repairs. Refer to“Product Support,” p. 46 of
this manual for instructions.
A data package is included with your unit. It contains this
manual, system drawings, applicable material SDSs,
other component manuals, warranty registration and
other applicable instructions based on the configuration
and options provided with the unit. The data package has
been placed in the unit in a clear plastic bag. The
documents need to be retained with the unit for future
reference.
Note: Items that have been shipped loose, such as
remote sensors, vibration isolators, and so on, are
shipped inside the air conditioner unless specified
otherwise by the customer. Grilles (if applicable)
are placed on top of the air conditioner inside the
unit’s carton. Remove and store these items in a
safe place unless you are using them immediately.
Site Preparation
CeilAir systems are designed with easy service access in
mind. Component access panels are located on the front
and rear sides of the equipment. Additional access to
some components may be obtained through the bottom of
the unit on spot cooler configurations. These units can be
fully serviced in the ceiling plenum. In order to have full
service access, the air conditioner must be located so that
ad- equate space is provided in front of all access panels.
Note: Working clearance requirements need to be
established prior to the mounting of the unit. Refer
to the National Electrical Code and local codes.
To minimize the effects of the environment surrounding
the conditioned space, certain steps must be taken. This is
especially true for critical/precision room preparation
(computer rooms/labs) requiring close tolerance control
of temperature and humidity. The conditioned space
should be well insulated and include a vapor barrier. The
installer should ensure that the proper insulation rating is
used based on the design of the space that was the basis
for the system selected. The following Table 1 is a
recommended minimum R-value (thermal resistance) to
ensure optimum equipment operation.
Table 1. Thermal resistance
Structure R-Value
Ceiling R-38
Wall R-21
Floor R-19
Door R-5
The vapor barrier is the single most important
requirement for maintaining environmental control in the
conditioned space. The vapor barrier in the ceiling and
walls can be polyethylene film. Concrete walls and floors
should be painted with a rubber or plastic-based paint.
Doors and windows should be properly sealed and a door
sweep used to minimize leakage. Outside or fresh air
should be kept to a minimum (as it adds to the cooling,
heating, dehumidification and humidifying loads), while
maintaining the requirement of the Indoor Air Quality
(IAQ) standard. Lack of these steps can cause erratic
operation, unstable room control and excessive
maintenance costs.
Rigging
WARNING
Heavy Object!
Failure to follow instructions below could result in unit
dropping which could result in death or serious injury,
and equipment or property-only damage.
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.
NOTICE
Unit Damage!
When moving the unit, it must be kept horizontal and
level to prevent damage.
CeilAir systems are designed to be kept in a horizontal
position. The unit is shipped on a skid to facilitate moving
prior to installation. A suitable lifting device should be
used to lift the unit from the bottom. A weight table is
provided for reference on the installation drawing. The
unit should always be stored indoors in a dry location prior
to installation.

Installation
AH-SVX008C-EN 13
Mounting
CeilAir TR-OHS systems are designed for ceiling mounting
in a suspended ceiling grid (spot cooler) or above the
suspended ceiling for ducted systems. See the below
figure.
Figure 6. Typical installation
(BY OTHERS)
2X4 CAB = TYPICAL for 2X4
H CAB or LARGE MODELS
Notes: Do not install the A/C system directly above
electronic equipment that may hinder
serviceability. Equipment must be level to
operate properly.
Indoor Equipment
CeilAir TR-OHS systems have a frame and panel
construction for unit rigidity and full service accessibility
while the unit is mounted in place. The unit is lifted from
underneath and secured into place using all-thread rods
passing through rubber grommets or a 4 in. x 4 in.
neoprene cork pad in the mounting arms on the sides of
the unit. Threaded rods, nuts and washers (field supplied
by others) must be secured so they do not loosen. (See
Figure 6, p. 13.)
Before mounting the unit, ensure the mounting structure
is able to support the weight of the equipment. Refer to the
weight table provided on the installation drawing. Secure
the unit via the pre-drilled mounting bolt holes with
suitable hardware for the application. An auxiliary drain
pan is recommended and can be mounted directly under
the cabinet (only on ducted models; see Figure 9, p. 14).
Outdoor Equipment
Install remote condensers/condensing units in a secure
location where the unit cannot be tampered with and the
power service switch cannot be inadvertently turned off.
Locate the remote condenser/condensing unit where the
fan is not likely to draw dirt and debris into the coil fins.
There should be at least one equipment-width of clearance
around the condenser to ensure adequate airflow to the
coil. Secure the condenser/condensing unit so the system
will not move during operation. Refer to the installation
drawing for the non-charged system weight. It is
recommended that the remote condenser/condensing
unit be mounted with vibration mounts to reduce the
amount of vibration transmitted to the mounting surface.
Controls
Note: Thermostats and control sensors should not be
located near a doorway, supply air register or area
where they would be exposed to direct sunlight or
other external heat sources.
A-Tech Programmable Thermostats
Mount the thermostat upright on an inside wall within the
conditioned room at a location that best represents the
average room temperature. In most cases, the thermostat
should be located near the common return air grille and
kept away from direct sunlight. Mount the thermostat at
least 18 in. from an outside wall and approximately 5 ft
above the floor. Follow the steps below for mounting.
Instructions for wiring the thermostat are found in Section
“A-Tech1.1ProgrammableThermostat,”p. 22and“A-Tech
1.2 Programmable Thermostat,” p. 22.
1. Open the case with a flathead screwdriver. Place blade
in slot and gently pry forward at the numbered
locations shown in the below figure.

Figure 7. A-Tech controller installation
Installation
14 AH-SVX008C-EN
2. Place the base temporarily over the wire hole opening
in the wall. Level the base and mark the screw locations
through the two provided mounting slots.
NOTICE
Sensor Damage!
Do not touch the temperature sensor on the bottom left
corner of the thermostat. The sensor can be damaged if
handled improperly.
3. If using the supplied anchors, drill two 3/16 in. holes
and tap in the wall anchors. If only the screws are being
used, drill two 3/32 in. holes.
4. Fasten the base to the wall using the supplied screws.
5. Connect wiring between the thermostat and
equipment. See the A-Tech wiring instructions in
Section “A-Tech 1.1 Programmable Thermostat,” p. 22
and “A-Tech 1.2 Programmable Thermostat,” p. 22..
6. Reinstall thermostat cover to base.
Figure 8. Spot cooler grille
.75 in/19 mm
THICK
GASKET
Figure 9. Ducted system typical air patterns
90° / RIGHTANGLE IN/OUT SAME FACESTRAIGHT-THRU
SUPPLY
AIR OUTLET

Installation
AH-SVX008C-EN 15
Advanced Controller
If the optional microprocessor controller is furnished, a
separate manual is included in the unit data package
provided with the unit. The controller user interface
display may be field mounted to a wall within the
conditioned space or it may be located outside the
conditioned space if desired. Refer to the supplemental
instructions provided with the mounting kit when
mounting the controller display. When locating the display
panel, consider the length of wire to be used. As an option,
a 30 ft, 75 ft or 150 ft long cable may be provided by Trane.
Optional Equipment
Note: Do not mount any optional equipment on the A/C
access panels of the unit.
Condensate Pump (Field Installed)
NOTICE
Equipment Damage!
Always follow manufacturer's instructions when in-
stalling a field-installed condensate pump. If
manufacturer's instructions were not provided with the
pump, contact Trane product support for the pump
documentation. Do not install the pump without first
reading the manufacturer's instructions. Failure to
exactly follow manufacturer's instructions may on rare
occasions result in serious damage to the TR-OHS unit
and the surrounding facility.
If the unit was not purchased with the factory-installed
condensate pump option, the shipped-loose condensate
pump should be mounted as near to the air conditioning
system as possible. The inlet hole in the pump must be
below the lowest part of the drain from the A/C unit. The
pump has two mounting supports so it can be hung on an
adjacent wall. Ensure that the pump is level for proper
operation.
A P-trap must be installed between the pump and the unit.
The height of the trap must be a minimum of 2 inches to
exceed the total static pressure of the system and ensure
proper water drainage from the drain pan.
Important: Properly size and vent the P-trap according
to applicable codes and best practices.
Non-Fused Service Switch
The non-fused service switch may be used to disconnect
main power and isolate the unit during maintenance and
service. The switch has a lockable handle to lock power out
during maintenance periods. The switch is typically
mounted to the A/C cabinet; however, it may be shipped
loose for field installation. The case has a top keyhole
mounting slot and two holes in each bottom corner for
mounting. The hardware for mounting the switch is field
supplied. Select suitable fasteners for the intended
mounting surface.
The non-fused service switch can be mounted near the
unit or in a central location. Non-fused service switches are
rated for either indoor or outdoor use. Ensure that the
proper type is used for your application.
Note: Refer to the National Electrical Code and local
codes for the appropriate mounting location.
Remote Sensors
The remote temperature sensor or temperature/humidity
(T/H) sensor must be located so that it will properly sense
the temperature and/or humidity conditions to be con-
trolled. The sensor should not be mounted near a doorway
or an area where it would be exposed to direct sunlight.
When locating the sensor, consider the length of wire to be
used. As an option, a 75 ft or 150 ft cable may be provided
by Trane. Refer to the applicable section that follows to
mount the sensor.For wiring details, refer to Section
“Controls,” p. 13 and to the electrical drawing provided
with the unit.
Remote Temperature Sensor (A-Tech)
Figure 10. Temperature sensor for A- Tech
Note: The remote temperature sensor has a maximum
range of 330 ft.
1. Install shielded or non-shielded two wire twisted cable
from the thermostat to the remote sensor location.
2. Open the sensor case by grasping the side and pulling
the two halves apart.
3. Use the sub-base as a template to mark the mounting
hole locations on the mounting surface. Drill size for
the wall anchors is 1/4 in. Mount the sub-base over the
wires coming out of the wall using the two screws and
anchors provided. Do not use hex head screws.
4. Strip 1/4 in. of insulation from the two wires at the
remote sensor. Install the wires in the terminals. The
wires can be connected with either polarity. Seal the
hole in the wall around the cable to eliminate any draft
that might affect the sensor.
5. Make the wiring connections. Refer to section “Remote
Temperature Sensor (A-Tech),” p. 27 and to the wiring
diagram supplied with your unit.
6. Replace the sensor cover.

Installation
16 AH-SVX008C-EN
Remote Temperature/Humidity Sensor (E²)
Figure 11. Temperature/humidity sensor for E²
controller
1. Remove the cover from the base of the sensor by
squeezing it at the top and bottom.
NOTICE
Sensor Damage!
Take care not to damage the exposed temperature/
humidity sensor elements on the PC board when the
cover is removed. The sensor elements can be
damaged if handled improperly.
2. Place the base temporarily against the mounting
surface.
3. Level the base. Mark and drill mounting holes through
at least two of the available slotted holes. Also, mark
through the large opening in the base and drill a hole
into the mounting surface for a control cable to pass
through the back of the base.
4. Run a three-conductor shielded cable through the
opening in the base, then secure the base with screws,
ensuring the word TOP on the PC board is oriented
upward.
5. Route the sensor control cable up to the control
terminal block in the electric box and terminate the
control wire. Refer to section “Remote Temperature/
Humidity Sensor (E²),” p. 16 and to the wiring diagram
supplied with your unit.
6. Seal the hole in the wall behind the sensor.
7. Replace the cover plate on the base.
Humidistat/Dehumidistat (Used with A-
Tech1.1/1.2 Thermostat)
Mounting the humidistat and/or dehumidistat is
performed in the same manner in “Remote Temperature
Sensor (A-Tech),” p. 15. It should be mounted to a wall
within the conditioned room at a location that best
represents the average humidity of the space. In most
cases, the humidistat and/or dehumidistat should be
located near the common return air grille. Mount the
humidistat and dehumidistat at least 18 in. from an outside
wall and approximately 5 ft above the floor.
Controls may be installed either on a flush switch box or on
a surface switch box. Follow the steps below for mounting.
Instructions for wiring the unit are provided in Section
“Humidistat/Dehumidistat,” p. 26.
1. Pull dial knob off, loosen screw (located at bottom of
unit) and remove cover.
2. Make wiring connections according to the wiring
diagram provided with your unit.
3. Mount the base with the two #6 screws provided.
4. For external setpoint, reinstall cover, tighten screw,
and replace dial knob.
5. For internal setpoint:
a. Turn dial plate to desired setting and tighten dial
lock screw.
b. Break off dial shaft at undercut.
c. Remove insert from cover.
d. Remove protective backing from adhesive on the
blank insert provided and press firmly in place on
cover.
e. Reinstall cover assembly and tighten screw. (If
additional security is required an Allen screw and
wrench are provided.)
f. Remove protective cover from face of cover insert.
Spot Water Detector
The spot water detector is normally placed on the floor or
in a field-supplied auxiliary drain pan located beneath the
unit.
It may be attached using double sided tape or with the
mounting holes provided in the flanges (one on each side).
Once it's in place, loosen the screws provided on the
mounting legs to adjust the height of the sensing probes.
When water is present, current will flow between the two
probes.
Figure 12. Spot water detector
Important: The probes must not touch the mounting
surface. Failure to adhere to this may result
in improper operation of equipment.
For wiring details, refer to “Remote Water Detector,” p. 26
and to the electrical drawing provided with the unit.

Installation
AH-SVX008C-EN 17
Cable Type Water Detector
Important: Do not allow the cable water detector to
contact metal (frame or condensate pan). It
must be mounted on the plastic stand-offs
provided with the water detector.
Figure 13. Cable type water detector
Do not allow the cable water detector to contact metal
(frame or condensate pan). It must be mounted on the
plastic stand-offs provided with the water detector.
Lay the cable water detector across the surface where
water could collect. When water is present, current will
flow between the two wires. A two conductor wire harness
is provided with a quick connect fitting on the end. The
harness mates to the fitting on the water detector cable
and connects it to the terminal block inside the electric box.
Air Distribution Connection
Spot Cooler
For units that are not ducted (Figure 8, p. 14), the air
conditioner should be mounted above the ceiling grid,
leaving sufficient space for the air grilles to rest on the
ceiling T-bar.
Placement of the grilles is important. The hinged filter
grille goes on the return air side of the unit. The 3-way
directional grille goes on the conditioned air discharge
side of the air conditioner. Gasketing is factory-supplied
for the air seal between the bottom flange of the air
conditioner and the grille. After mounting the air
conditioner, attach the gasket to the bottom flange, then
lower the air conditioner until the gasket meets the grille,
as shown in Figure 8, p. 14.
Ducted Systems
There are three basic configurations of airflow patterns:
90º/right angle, straight-through and in/out-same-face
(see Figure 9). When determining ducting requirements,
always consult your local and state codes. The duct system
should be designed to allow the air to move with as little
resistance as possible. Several factors determine ducting
material and size. These factors are pre-determined, refer
to your ducting system schematic.
The connection of ducting to the unit is typically
accomplished with a 1 in. duct flange. Supply air outlet and
return air inlet ducts will require a field-provided duct
flange (refer to the installation drawing provided with the
unit). The connection of ductwork to the unit may be made
with either pop rivets or self-tapping screws.
Piping Connections
Refrigerant
Self-Contained Systems
No refrigeration connections are required for self-
contained air, water or glycol-cooled systems (Models TR-
OHS- 012/040-AS, TR-OHS-012/120-C and TR-OHS-012/
120- W/G-( )).
Split Systems
Split air-cooled systems will require field refrigeration
piping. All split systems are shipped with a dry nitrogen
charge of 100 psig. Systems utilizing a remote condenser
will require a copper liquid line and discharge line (see
section “Remote Air Cooled Condensers (AR Models),”
p. 19). Systems utilizing a remote condensing unit (RCU)
will require a copper liquid line and suction line (see
section “Remote Air Cooled Condensers (AR Models),”
p. 19).
All refrigeration piping should be installed with high
temperature brazed joints. Use standard refrigeration
practices for piping supports, leak testing, dehydration
and charging of the refrigeration circuits. The refrigerant
piping should be isolated by the use of vibration isolating
supports.
Provide supports (clamps or hangers) as necessary every
5 to 10 ft along piping runs to minimize vibration and noise
transmission. To reduce vibration transmission and
prevent pipe damage, use a soft flexible material to pack
around the piping when sealing openings in walls.
Wrap wet rags around the pipes between the areas to be
soldered and any nearby refrigeration components to
keep excessive heat from traveling through the pipe and
causing damage. Clear all pipe connections of debris and
prep connections for soldering. Use only "L" or "K" grade
refrigerant copper piping. Be careful not to allow solder/
piping debris to get inside refrigerant lines. Silver solder
containing a minimum of 15% silver is recommended. Dry
nitrogen should be flowing through the tubing while
soldering at a rate of not less than 1-2 CFM.
Refrigerant lines for split systems must be sized according
to the piping distance between the evaporator and the
condenser/condensing unit. Each valve, fitting and bend in
the refrigerant line must be considered in this calculation.
Pipe sizes are given for "equivalent feet”, not linear feet. Do
not confuse the terminologies. For example, a 7/8 in.
standard 90° elbow has an equivalent length of 1.5 ft; a 7/
8 in. branch Tee has an equivalent length of 3.5 ft. These
corrections must be accounted for when sizing your
piping. Refer to the following table for standard equivalent
lengths, in feet, of straight pipe.

Table 2. Pipe equivalent lengths
Equivalent Length (ft) of Straight Pipe
O.D.
(in.) Line
Size
Globe
Valve
Angle
Valve 90º Elbow 45º Elbow Tee Line Tee Branch
1/2 9.0 5.0 0.9 0.4 0.6 2.0
5/8 12.0 6.0 1.0 0.5 0.8 2.5
7/8 15.0 8.0 1.5 0.7 1.0 3.5
1 1/8 22.0 12.0 1.8 0.9 1.5 4.5
1 3/8 28.0 15.0 2.4 1.2 1.8 6.0
Installation
18 AH-SVX008C-EN
Oil traps must be included every 20 ft in the vertical risers
and the refrigerant lines must be sloped in the horizontal
lines to ensure proper oil return to the compressor. An
inverted trap is required on the discharge line of the
remote condenser to help prevent oil and liquid from
flooding back to the compressor.
Notes: In the following tables:
•The line sizes represent the correct size for individual
refrigeration circuits. Dual circuit units, (models 048D
to 120D), have two separate pairs of refrigeration lines,
one per compressor.
•All pipe lengths are "Equivalent Length," which
accounts for the linear pipe length as well as
equivalent length of valves, elbows and Tee's as
shown in Table 2, p. 18.
Table 3. Recommended discharge line sizes for R407C
refrigerant
Model No./
Total Btu/h
Capacity
Compressor to Condenser O.D. (in.)
50 ft or less 100 ft or less 150 ft or less
012/12,000 1/2 5/8 5/8
018/18,000 1/2 5/8 5/8
024/24,000 5/8 5/8 3/4
032/32,000 5/8 3/4 3/4
040/40,000 3/4 3/4 7/8
048/48,000 3/4 7/8 7/8
048D/48,000 5/8 5/8 3/4
060/60,000 3/4 7/8 1-1/8
072D/72,000 5/8 3/4 3/4
084D/84,000 3/4 7/8 7/8
120D/120,000 3/4 7/8 1-1/8
Table 4. Recommended liquid line sizes for R407C
refrigerant (condenser to receiver)
Model No./
Total Btu/h
Capacity
Compressor to Condenser O.D. (in.)
50 ft or less 100 ft or less 150 ft or less
012/12,000 1/2 1/2 1/2
018/18,000 1/2 1/2 1/2
024/24,000 1/2 5/8 5/8
032/32,000 1/2 5/8 5/8
040/ 40,000 5/8 5/8 5/8
048/48,000 5/8 5/8 3/4
048D/48,000 1/2 1/2 5/8
060/60,000 5/8 3/4 3/4
072D/72,000 1/2 5/8 5/8
084D/84,000 5/8 5/8 3/4
120D/120,000 5/8 3/4 3/4
Table 5. Recommended suction line sizes for R407C
refrigerant
Model No./
Total Btu/h
Capacity
Line O.D. (in.)
50 ft or less 100 ft or less
H V H V
012 / 12,000 3/4 3/4 3/4 3/4
018 / 18,000 3/4 3/4 3/4 3/4
024 / 24,000 3/4 3/4 7/8 7/8
032 / 32,000 7/8 7/8 7/8 3/4
040 / 40,000 7/8 7/8 1-1/8 1-1/8
048 / 48,000 1-1/8 1-1/8 1-1/8 1-1/8
048D / 48,000 3/4 3/4 7/8 7/8
060 / 60,000 1-1/8 1-1/8 1-1/8 1-1/8
072D / 72,000 7/8 7/8 7/8 3/4
084D /84,000 1-1/8 1-1/8 1-1/8 1-1/8

Installation
AH-SVX008C-EN 19
Suction line sizes are for 50ºF through 30ºF suction temp at
48 through 26 psig.
Important: Do not exceed the maximum line lengths
for the system configurations listed below:
•RCU with hot gas bypass 50 ft
•Remote condensing unit 100 ft
•Remote air cooled condenser 150 ft
•Vertical runs are based on a total rise of 30 equivalent
ft. For longer rises, individual calculations should be
made. Sizes assume the use of single risers; double
rises may be necessary.
Remote Air Cooled Condensers (AR Models)
Systems utilizing air cooled condensers must not have a
refrigerant line pressure drop over 14 psig across the
condenser and the interconnecting piping to the
condenser sections.
Note: Ensure proper condenser selection to maintain
reasonable sub-cooling temperatures.
If the condenser is installed above the evaporator, the
discharge line should include a P-trap at the lowest point in
the piping. The highest point in the discharge line should
be above the condenser coil and should include an
inverted trap to help prevent oil and liquid from flooding
back to the compressor during off cycles.
If the condenser is installed below the evaporator, an
inverted trap the height of the evaporator coil is required
on the liquid line to help prevent oil and liquid from
flooding back to the compressor during off cycles.
Refer to the refrigerant-appropriate Recommended
Discharge Line Sizes Table 3, p. 18, Recommended Liquid
Line Sizes Table 4, p. 18 and Recommended Suction Line
Sizes Table 5, p. 18.
Remote Air Cooled Condensing Units (AHU
Models)
When installing a remote condensing unit above the
evaporator, the suction line should be P-trapped at the
evaporator.
When installing remote condensing units below the
evaporator, the suction line should be trapped with an
inverted trap the same height as the evaporator coil. This
prevents migration of liquid refrigerant to the compressor
during off cycles.
Note: Do not exceed 15 ft of vertical distance when
installing the condensing unit below the
evaporator.
All suction lines must be insulated to prevent
condensation from forming on the pipes. Refer to the
Recommended Suction Line and Recommended Liquid
Line sizing tables.
Chilled Water, Water/Glycol and Hot Water
Reheat Piping
The piping connections for water/glycol, chilled water and
systems with hot water reheat are sweat connections. Pipe
sizes may not necessarily be the same as the unit
connection. Piping should be sized to match the required
system pressure drop and pump capacity (if applicable)
and may require reducing fittings to match the connection
size on the air conditioner.
NOTICE
Equipment Damage
Fluid coils and associated piping circuits are
pressurized and sealed when they leave the factory.
When installing and filling water/glycol, chilled water
and optional hot water reheat loops, all air must be
bled from the piping system.
The piping system must be flushed prior to operating
the system. Failure to do so will result in equipment
problems.
The recommended ethylene glycol solution ratio is 40%
glycol to 60% water. Glycol-cooled systems with a low
entering fluid temperature and all chilled water systems
should have insulated piping.
WARNING
Hazardous Chemical!
Glycol is a colorless, thick, odorless liquid. When
heated or misted, it can cause: throat irritation, eye
irritation, headache, and in extreme cases can lead to a
coma and fatality. Chronic exposure in large doses can
cause pulmonary and kidney issues.
A strainer should be included in the water/glycol, chilled
water and optional hot water reheat line. Once the system
is operational, the fluid runs through the strainer, which
removes any foreign objects. The strainer screen should
be cleaned periodically.
Condensate Drain Line
Gravity Drain
A 7/8 in. O.D. copper (sweat type) line is provided to drain
the condensate drain pan. This line also drains the
humidifier, if applicable. A "P" type condensate trap must
be installed. The height of the trap must be at least 2 inche
to exceed the total static pressure of the system and
ensure proper water drainage from the drain pan. The
120D / 120,000 1-1/8 1-1/8 1-1/8 1-1/8
Table 5. Recommended suction line sizes for R407C
refrigerant (continued)
Model No./
Total Btu/h
Capacity
Line O.D. (in.)
50 ft or less 100 ft or less
H V H V

Installation
20 AH-SVX008C-EN
drain line must be located so it will not be exposed to
freezing temperatures. The drain line should be the full
size of the connection. See the installation drawing
provided with your unit for the size and location of the
condensate drain line.
NOTICE
Coil Fins Damage
Do not use chloride-based water conditioning additives
in the condensate drain pans. They cause corrosion on
the coil fins.
Important: Properly size and vent the P-trap according
to applicable codes and best practices.
Note: During normal operation the optional humidifier
drains hot water into the condensate drain line. As
an option, a separate drain line may be provided for
the humidifier.
Condensate Pump
A condensate pump (see figure below) is used to
automatically remove condensate from the air conditioner
and flush water from the humidifier (if applicable). A P-trap
is installed for proper condensate drainage. The height of
the trap is a minimum of 2 in. on most standard systems
to ensure proper water drainage of the drain pan. The
condensate pump discharge line should be 1/2 in. I.D.
(maximum) vinyl tubing or 1/2 in. O.D. (maximum) copper
pipe to prevent excessive back flow to pump.
Figure 14. Condensate pump
Note: Pour some water into the condensate drain(s) prior
to start-up. This fills the trap and prevents air from
being drawn up the drain lines.
Humidifier (Optional)
CeilAir systems may include an optional electrode steam
humidifier. The humidifier empties into the condensate
drain pan during the flush/drain cycle. A water supply line
must be connected to the humidfier copper tubing inlet
connection supplied by the factory. Refer to the installation
drawing provided with your unit for the size and location
of the connection. The humidifier requires normal tap
water as the water supply. If the supply water is high in
particulates, an external filter may be needed.
NOTICE
Humidifier Damage
Do not use demineralized water in the humidifier.
Note: Refer to the humidifier operator's manual supplied
with the TR-OHS unit for complete manufacturer's
information on the humidifier and for supply water
recommendations.
Utility Connections
Main Power
CeilAir units are available in single- or three-phase
variations and a wide range of voltages. Examine the unit
nameplate, located on the outside of the cabinet in close
proximity of the electric box, to determine the operating
voltage, frequency and phase of the system (see Figure 15,
p. 21). (Note that the unit serial and model numbers are
also found on the nameplate.) Provided power must meet
the listed specifications. The supply voltage measured at
the unit must be within ±10% of the voltage specified on
the system nameplate, with the exceptions noted below.
The nameplate also provides the full load amps (FLA) the
unit will draw under full design load, the minimum circuit
ampacity (MCA) for wire sizing, and the maximum fuse
size (MAX FUSE) for circuit protection.
Important: If the nameplate states MAX FUSE/CKT
BKR, fuses or an HACR type circuit breaker
are required to protect the system. Other
protection devices are not allowed based
upon the product listing.
The unit is provided with terminals for all required field-
wiring. It is important to identify the options that were
purchased with the unit in order to confirm which field
connections are required. Refer to the electrical drawing(s)
supplied with the unit for information about power and
control field-wiring.