Packaged Rooftop Air Conditioners
Precedent™- Electric/Electric
3 – 10 Tons – 60 Hz
Model Numbers
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 alter ed 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.
Warnings, Cautions and Notices. Note that warnings,
cautions and notices appear at appropriate intervals
throughout this manual. Warnings are provide to alert
installing contractors to potential hazards that could result
in death or personal injury . Cautions are designed to alert
personnel to hazardous situations that could result in
personal injury, while notices indicate a situation that
could result in equipment or property-damage-only
accidents.
Your personal safety and the proper operation of this
machine depend upon the strict observance of these
precautions.
Read this manual thoroughly before operating or servicing
this unit.
ATTENTION: Warnings, Cautions and Notices appear at
appropriate sections throughout this literature. Read
these carefully:
WARNING
CAUTIONs
NOTICE:
Indicates a potentially hazardous
situation which, if not avoided, could
result in death or serious injury.
Indicates 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.
Indicates a situation that could result in
equipment or property-damage only
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 af fect 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. T rane advocates the responsible handling of
all refrigerants-including industry replacements for CFCs
such as HCFCs and HFCs.
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.
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, y ou MUST f ollow r equir ements 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.
WARNING
Personal Protective Equipment (PPE)
Required!
Installing/servicing this unit could result in exposure to
electrical, mechanical and chemical hazards.
•Before installing/servi cin g th is un it, technicians
MUST put on all P ersonal Protective Equipmen t (PPE)
recommended for the work being undertaken.
AL W A YS r efer to appr opriate MSDS sheets and OSHA
guidelines for proper PPE.
•When working with or ar ound hazar dous chemi cals,
ALWAYS refer to the appropriate MSDS sheets and
OSHA guidelines for information on allowable
personal exposure levels, proper respiratory
protection and handling recommendations.
•If there is a risk of arc or flash, te chnicians MUST put
on all Personal Protective Equipment (PPE) in
accordance with NFPA 70E or other country-specific
requirements for arc flash protection, PRIOR to
servicing the unit.
Failure to f ollow recommendations could result in death
or serious injury.
A Unpowered Convenience Outlet
B Powered Convenience Outlet
(three-phase only)
7
7
3,7
3,7
Digit 21 - Communications
Sensor
29
DCV
3
29
Options
0No Communications Interface
1Trane Communications Interface
2LonTalk® Communications Interface
3Novar 2024 Controls
4Novar 3051 Controls without Zone
5Novar 3051Controls Interface with
9
29
6BACnet™ Communications Interface
Digit 22 - Refrigeration System
Option
0Standard Refrigeration System
B Dehumidification Option
10
21,22
Digit 23 - Refrigeration Controls
17
25
26
Note: Applicable to Digit 7 = E, F
0No Refrigeration Control
1Frostat
2Crankcase Heater
3Frostat
11,28
11,28
and Crankcase Heater
5
2
Digit 24 - Smoke Detector
0No Smoke Detector
A Return Air Smoke Detector
B Supply Air Smoke Detector
C Supply and Return Air Smoke
Detectors
12,13
D Plenum Smoke Detector
12,13
16
Digit 25 - System Monitoring
Controls
0No Monitoring Control
1Clogged Filter Switch
2Fan Failure Switch
3Discharge Air Sensing Tube
4Clogged Filter Switch and Fan
Failure Switch
24
5Clogged Filter Switch and Discharge
Air Sensing Tube
6Fan Failure Switch and Discharge Air
Sensing Tube
14
14
7Clogged Filter Switch, Fan Failure
Switch and Discharge Air
Sensing Tube
8Novar Return Air Sensor
8
(NOVAR 2024)
9Novar Zone Temp Sensor
(NOVAR 3051)
14
15,29
18,29
A Condensate Drain Pan Overflow
Switch
B Clogged Filter Switch
Condensate Drain Pan Overflow
8
Switch
C Fan Failure Switch
Drain Pan Overflow Switch
D Discharge Air Sensing
Condensate Drain Pan Overflow
14
14
14
14
14
14
14
and
and Condensate
14
and
2
RT-SVX22J-EN5
Page 6
Model Number Description
Switch
EClogged Filter Switch
FClogged Filter Switch
G Fan Failure Switch, Discharge Air
H Clogged Filter Switch
14
Switch
Overflow Switch
Air Sensing Tube
Drain Pan Overflow Switch
Sensing Tube
Drain Pan Overflow Switch
Switch
and Condensate Drain Pan Overflow
Switch
and Condensate Drain Pan
14
, Discharge Air Sensing
14
, Fan Failure
14
, Discharge
14
and Condensate
14
and Condensate
14
, Fan Failure
14
Digit 26 - System Monitoring
Controls
0No Monitoring Controls
A Demand Control Ventilation
(CO
2
30,31
)
Digit 27 - Unit Hardware
Enhancements
0No Enhancements
1Stainless Steel Drain Pan
Model Number Notes
1. Available on 3-5 ton models.
2. Standard on 4-5 Ton E3,4,W and
6-10 Ton Heat Pumps and all High
Efficiency models.
3. Not available with
electromechanical controls.
4. Manual outside air damper will
ship factory supplied within the
unit, but must be field installed.
5. High pressure control is standard
on all units.
6. On 3-5 ton, multispeed direct
drive is standard on single phase
and 15 SEER. On 6-10 ton,
multispeed direct drive is
standard on all 10 ton and 7.5-8.5
ton high efficiency. Belt drive is
standard on all other units.
Digit 15 = 0
Standard Efficiency
1 Phase = High Efficiency Multispeed Direct
Drive Motor
3 Phase (3-8½ Ton) = Belt Drive
3 Phase (10 T on) = Ultra High Efficiency Direct
Drive Plenum Fan
High Efficiency
1 Phase = High Efficiency Multispeed Direct
Drive Motor
3 Phase (3-5 ton) = High Efficiency Multispeed
Direct Drive Motor
3 Phase (3-5 ton w/Dehumidification) = Belt
Drive Motor
3 Phase (7½-10 ton) = Ultra High Efficiency
Direct Drive Plenum Fan
7. Economizer with Barometric
Relief is for downflow configured
units only. Order Economizer
without Barometric Relief for
horizontal configuration.
Barometric Relief for horizontal
configured units must be ordered
as field installed accessory.
8. Through the base electric
required when ordering
disconnect/circuit breaker
options.
9. Requires use of Disconnect or
Circuit Breaker.
Not Available
Standard Efficiency
10 Ton w/575V
High Efficiency
3-5 ton w/Standard Indoor Motor w/460V
10. Standard metering devices are
TXVs.
1 1 . Fro stat cannot be field installed in
electro-mechanical units.
12. The return air smoke detector
may not fit up or work properly on
the Precedent units when used in
conjunction with 3rd party
accessories such as bolt on heat
wheels, economizers and power
exhaust. Do not order the return
air smoke detectors when using
this type of accessory.
13. Return Air Smoke Detector
cannot be ordered with Novar
Controls.
14. These options are standard when
ordering Novar Controls.
15. This option is used when
ordering Novar Controls.
16. Not available with high
temperature duct sensor
accessory.
17. Digit 15 = 2
Standard Efficiency
1 Phase = Not Available
3 Phase = Not Available
High Efficiency
1 Phase = Not Available
3 Phase (3-5 ton) = May be Ordered
3 Phase (3-5 ton w/Dehumidification) = Not
Available
3 Phase (6-10 ton) = Not Available
18. Novar Sensor utilized with
Digit 21 = (4) Novar 3051 Controls
without Zone Sensor.
19. Available for 10 ton standard
efficiency models only .
20. Available for 3, 4, 5, 6, 7½, 8½ ton
standard/high efficiency models
only.
21. Requires selection of 2” Pleated
Filters (option B or C) for Digit 16.
22. Not available on 6 ton units and
all single phase or standard
efficiency.
23. Standard on TSC 6, 7½ (single
and dual systems), 8½, 10 ton
standard efficiency mo de ls and
THC 4, 5, 6, 7½ ton high efficiency
models (except for
dehumidification models).
24. Epoxy coil and epoxy with
hailguard options are not
available for units with
microchannel condenser coil.
25. Single Zone VA V is only available
on 7.5-10 ton high efficiency and
10 ton standard efficiency
products with ReliaT el™ controls.
26. Multi-speed indoor fan ava ilable
only on 7.5 & 8.5 ton high
efficiency, and 10 ton products
with ReliaTel™ controls.
27. Motorized Outside Air Damper is
not available on Multi-Speed or
SZVAV (Single Zone Variable Air
Volume) products.
28. Frostat standard on Multi-Speed
and SZVA V (Single Zone V ariable
Air Volume)
products.
29. Novar is not available with SZVA V
products.
30. Demand Control Venti latio n no t
available with electromechanical
controls.
31. Demand Control Ventilation
Option includes wiring only. The
sensor is a field-installed only
C0
2
option.
6 RT-SVX22J-EN
Page 7
General Information
Unit Inspection
As soon as the unit arrives at the job site
•V erify that the nameplate data matches the data on the
sales order and bill of lading (includin g 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.
If the job site inspection of the unit reveals damage or
material shortages, file a claim with the carrier
immediately. Specify the type and extent of the damage on
the “bill of lading” before signing.
•Visually inspect the internal components for shippi ng
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 th e 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.
Storage
Take precautions to prevent condensate from forming
inside the unit’s electrical compartments and motors if:
1. the unit is stored before it is installed; or,
2. the unit is set on the roof curb, and temporary heat is
provided in the building. Isolate all sid e panel service
entrances and base pan openings (e.g., conduit holes,
Supply Air and Return Air 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 ““Unit Start-Up,” p. 46”.
The manufacturer will not assume any responsibility for
equipment damage resulting from condensate
accumulation on the unit’s electrical and/or mechanical
components.
Unit Nameplate
A Mylar unit nameplate is located on the unit’s corner
support next to the filter access panel. It includ es the unit
model number, serial number, electrical characteristics,
refrigerant charge, as well as other pertinent unit data.
Compressor Nameplate
The nameplate for the compressors are located on the side
of the compressor.
Microchannel Condenser Barcode ID
Barcode decal used for condenser coil part identification
can be located on the vertical header and top of coil's inlet/
outlet side.
Unit Description
Before shipment, each unit is leak tested , dehydrated,
charged with re fr igerant and compressor oil, and run
tested for proper control operation.
The condenser coils are either aluminum fin, mechanically
bonded to copper tubing or all aluminum microchannel.
Direct-drive, vertical discharge condenser fans are
provided with built-in thermal overload protection.
There are two control systems offered for these units. The
electromechanical control option uses a thermostat to
perform unit functions. The ReliaTel™ Control Module is a
microelectronic control system that is referred to as
“Refrigeration Module” (RTRM). The acronym RTRM is
used extensively throughout this document when
referring to the control system network.
These modules through Proportional/Integral control
algorithms perform specific unit functions that governs
unit operation in response to; zone temperature, supp ly air
temperature, and/or humidity conditions depending on
the application. The stages of capacity control for these
units are achieved by starting and stopping the
compressors.
The RTRM is mounted in the control panel and is factory
wired to the respective internal components. The RTRM
receives and interprets information from other unit
modules, sensors, remote panels, and customer binary
contacts to satisfy the applicable request for cooling.
Economizer Control Actuator (Optional)
Electromechanical Control
The ECA monitors the mixed air temperature, ambient dry
bulb temperature and local minimum position setpoint
sensors, if selected, to control dampers to an accuracy of
+/- 5% 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 inch pound s of to rque an d
is powered by 24 VAC.
ReliaTel™ Control
The ECA monitors the mixed air temperature, return air
temperature, minimum position setpoint (local or
remote), power exhaust setpoint, CO
ambient dry bulb/enthalpy sensor or comparative
humidity (return air humidity against ambient humidity)
setpoint, CO2, and
2
RT-SVX22J-EN7
Page 8
General Information
sensors, if selected, to control dampers to an accuracy of
+/- 5% 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 inch pounds of torque and
is powered by 24 VAC.
RTCI - ReliaTel™ Trane Communication
Interface (Optional)
This module is used when the application calls for an
ICSTM building management type control system. It
allows the control and monitoring of the system through
an ICS panel. The module can be ordered from the factory
or ordered as a kit to be field installed. Follow the
installation instruction that ships with each kit when field
installation is necessary.
RLCI - ReliaTel™ LonTalk Communication
Interface (Optional)
This module is used when the application calls for an
ICSTM building management type control system that is
LonT alk. It allows the control and monitoring of the system
through an ICS panel. The module can be ordered from the
factory or ordered as a kit to be field installed. Follow the
installation instruction that ships with each kit when field
installation is necessary.
This module is used when the application calls for an open
BACnet protocol. It allows the control and monitoring of
the system through an ICS panel. The module can be
ordered from the factory or as a kit to be field installed.
Follow the installation instructions that ships with eac h kit
when field installation is necessary.
RTOM - ReliaTel™ Options Module (Standard
on 17 Plus, 7.5 Ton & 8.5 Ton High Efficiency
with ReliaTel, 10 Ton with ReliaTel)
The RTOM monitors the supply fan proving, clogged filter,
supply air temperature, exhaust fan setpoint, supply air
tempering, Frostat™, smoke detector, and V ariable Speed
Fan Control (17 Plus units only). Refer to system input
devices and functions for operation.
System Input Devices & Functions
The RTRM must have a zone sensor or thermostat input in
order to operate the unit. The flexibility of having several
mode capabilities depends upon the type of zone sensor or
thermostat selected to interface with the RTRM.
The descriptions of the following basic Input Devices used
within the RTRM network are to acquaint the operator with
their function as they interface with the various modules.
Refer to the unit’s electrical schematic for the specific
module connections.
The following controls are available from the factory for
field installation.
Supply Fan Failure Input (Optional)
The Fan Failure Switch can be connected to sense indoor
fan operation:
FFS (Fan Failure Switch) If air flow through the unit is not
proven by the differential pressure switc h connected to the
RTOM (factory set point 0.07 “w.c.) within 40 seconds
nominally, the RTRM will shut off all mechanical
operations, lock the system out, send a diagnostic to ICS,
and the SERVICE output wi ll flash. The system will remain
locked out until a reset is initiated either manually or
through ICS.
Clogged Filter Switch (Optional)
The unit mounted clogged filter switch monitors the
pressure differential across the return air filters. It is
mounted in the filter section and is connected to the
RTOM. A diagnostic SERVICE signal is sent to the remote
panel if the pressure differential across the filters is at least
0.5" w.c. The contacts will automatically open when the
pressure differential across the filters decreases to
approximately 0.4" w.c. The clogged filter output is
energized when the supply fan is operating and the
clogged filter switch has been closed for at least 2 minutes.
The system will continue to operate regardless of the
status of the filter switch.
Note: On units equipped with factory installed MERV 13
filters, a clogged filter switch with different
pressure settings will be installed. This switc h will
close when the differential pressure is
approximately 0.8' w.c. and open when the
differential falls to 0.7" w.c.
Condensate Drain Pan Overflow Switch
(Optional)
ReliaTel Option
This input incorporates the Condensate Overflow Switch
(COF) mounted on the drain pan and the ReliaTel Options
Module (RTOM). When the condensate level reaches the
trip point for 6 continuous seconds, the RTOM will shut
down all unit functions until the overflow condition has
cleared. The unit will return to normal operation after 6
continuous seconds with the COF in a non-tripped
condition. If the condensate level causes unit shutdown
more than 2 times in a 3 days period, the unit will be
locked-out of operation requiring manual reset of
diagnostic system through Zone Sensor or Building
Automation System (BAS). Cycling unit power will also
clear the fault.
Electromechanical Option
This input incorporates the condensate overflow switch
(COF), COF Relay , COF Time Delay . When the condensate
level reaches the trip point, the COF relay energizes and
opens the 24VAC control circuit which disables the unit.
Once the 24VA C control circuit is opened, a delay timer will
prevent unit start-up for three minutes.
8 RT-SVX22J-EN
Page 9
General Information
Compressor Disable (CPR1/2)
This input incorporates the low pressure control (LPC) of
each refrigeration circuit and can be activated by opening
a field supplied contact installed on the LTB.
If this circuit is open before the compressor is started, the
compressor will not be allowed to operate. Anytime this
circuit is opened for 1 continuous second 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
contacts close.
If four consecutive open conditions occur during the first
three minutes of operation, the compressor for that circuit
will be locked out, a diagnostic communicated to the
remote panel (if installed), and a manual reset will be
required to restart the compressor.
Low Pressure Control
ReliaTel Control
When the LPC is opened for 1 continuous second, the
compressor for that circuit is turned off immediately . The
compressor will not be allowed to restart for a minimum
of 3 minutes.
If four consecutive open conditions occur during an active
call for cooling, the compressor will be locked out, a
diagnostic communicated to ICS™, if applicable, and a
manual reset required to restart the compressor. On dual
compressor units only the affected compressor circuit is
locked out.
Electromechanical Control
When the LPC is opened, the compre ssor for that circuit is
turned off immediately . The compressor will restart when
the LPC closes.
High Pressure Control
ReliaTel Control
The high pressure controls are wired in series between the
compressor outputs on the RTRM and the compress or
contactor coils. If the high pressure control switc h opens,
the RTRM senses a lack of current while calling for cooling
and locks the compressor out.
If four consecutive open conditions occur during an active
call for cooling, the compressor will be locked out, a
diagnostic communicated to ICS™, if applicable, and a
manual reset required to restart the compressor. On dual
compressor units only the affected compressor circuit is
locked out.
Electromechanical Control
When the HPC is opened, the compressor for that circuit is
turned off immediately . The compressor will restart when
the HPC closes.
Power Exhaust Control (Optional)
ReliaTel Control
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.
With the optional ventilation override accessory, the
power exhaust fan is independent of the indoor fan.
The setpoint panel is located in the return air section and
is factory set at 25%.
Electromechanical Control
The power exhaust fan is started whenever the indoor fan
is on and the adjustable damper limit switc h DLS is closed.
Lead/Lag Control (Dual Circuit Only)
ReliaTel Control Only
Lead/Lag is a selectable input located on the RTRM. The
RTRM is configured from the factory with the Lead/Lag
control disabled. T o activate the Lead/Lag function, simply
cut the wire connected to J3-8 at the RTRM. When it is
activated, each time the designated lead compressor is
shut off due to the load being satisfied, the lead
compressor or refrigeration circuit switches. When the
RTRM is powered up, i.e. af ter a power failure, the control
will default to the number one circuit compressor. Lead/
Lag is not available on Multi-Speed Indoor Fan, or Single
Zone Variable Air Volume (SZVAV) products.
Zone Sensor Module (ZSM) (BAYSENS106*)
This electronic sensor features three system switch
settings (Heat, Cool, and Off) and two fan settings (On
and Auto). It is a manual changeover control with single
setpoint. (Cooling Setpoint Only)
Zone Sensor Module (ZSM) (BAYSENS108*)
This electronic sensor features four system switch settings
(Heat, Cool, Auto, and Off) and two fan settings (On and
Auto). It is a manual or auto changeover control with dual
setpoint capability. It can be used with a remote zone
temperature sensor BAYSENS077*.
Zone Sensor (BAYSENS110*)
This electronic sensor features four system switch settings
(Heat, Cool, Auto, and Off) and two fan settings (On and
Auto) with four system status LED’ s. It is a manual or auto
changeo ver control with dual setpoint capabili ty. It can be
used with a remote zone temperature sensor
BAYSENS077*.
Field installed, wall mounted humi dity sensor is used to
control activation of Enhanced Dehumidification and the
Hot Gas Reheat Dehumidification options. Humidity set
points can be selected for relative humidity levels between
RT-SVX22J-EN9
Page 10
General Information
40% and 60% by adjusting the DEHUMID setting on the
ReliaTel Options Module. See Figure 42, p. 34.
Field installed, duct mounted humidity sensor is used to
control activation of Enhanced Dehumidification and the
hot gas reheat dehumidification options. Humidity set
points can be selected for relative humidity levels between
40% and 60% by adjusting the DEHUMID setting on the
ReliaTel Options Module. See Figure 42, p. 34.
Programmable Zone Sensor - (BAYSENS119*)
This 7 day programmable sensor features 2, 3 or 4 periods
for Occupied or Unoccupied programming per d ay. If the
power is interrupted, the program is retained in
permanent memory. If power is off for an extended period
of time, only the clock and day may have to be reset.
The Zone Sensor allows selection of 2, 3 or 4 system
modes (Heat, Cool, Auto, and Off), two fan modes (On and
Auto). It has dual temperature selection with
programmable start time capability.
The occupied cooling set point ranges between 45 and 98
º F. The heating set point ranges between 43 and 96ºF.
A liquid crystal display (LCD) displays zone temperature,
temperature set points, day of the week, time, and
operational mode symbols.
The Option Menu is used to enable or disable applicable
functions, i.e.; Morning Warm-up, Economizer minimum
position override during unoccupied status, Fahrenheit or
Centigrade, Supply air tempering, Remote zone
temperature sensor, 12/24 hour time display, Smart fan,
and Computed recovery.
During an occupied period, an auxiliary relay rated for 1.25
amps @ 30 volts AC with one set of single pole double
throw contacts is activated.
Status Inputs (4 Wires Optional)
The ZSM can be wired to receive four (4) operating status
signals from the RTRM (HEAT, COOL, SYSTEM “ON”,
SERVICE).
Four (4) wires from the RTRM should be connected to the
appropriate terminals (7, 8, 9 & 10) on the ZSM.
Remote Zone Sensor (BAYSENS073*)
This electronic sensor features remote zone sensing and
timed override with over ride cancellation. It is used with a
Trane Integrated Comfort™ building management
system.
Remote Zone Sensor (BAYSENS074*)
This electronic sensor features single setpoint capability
and timed override with override cancellation. It is used
with a Trane Integrated Comfort™ building management
system.
Remote Zone Sensor (BAYSENS016*)
This bullet type temperature sensor can be used for
outside air (ambient) sensing, return air temperature
sensing, supply air temperature sensing, remote
temperature sensing (uncovered). Wiring procedures vary
according to the particular application and equipment
involved. Refer to the unit’s wiring diagrams for proper
connections.
Remote Zone Sensor (BAYSENS077*)
This electronic sensor can be used with BAYSENS106*,
108*, 110*, 119* Remote P anels. When this sensor is wired
to a BA YSENS119* Remote P anel, wiring must be 18 A WG
Shielded Twisted P air (Belden 8760 or equivalent). Refer to
the specific Remote Panel for wiring details.
Wireless Zone Sensor (BAYSENS050)
This electronic sensor features five system settings (Auto,
Off, Cool, Heat, and Emerg ency Heat) and with On and
Auto fan settings. It is a manual or auto c hangeover control
with dual setpoint capability. Other features include a
timed override function, lockable system settings, and
Fahrenheit or Celsius temperature display. Included with
the wireless zone sensor will be a receiver that is to be
mounted inside the unit, a mounting bracket, and a wire
harness.
Electromechanical Control
The unit must have a thermostat to operate.
•BAYSTAT151
• Single Stage - 1 Heat/1 Cool
•BAYSTAT155
• Multi Stage - 3 Heat/2 Cool - Can be Used for
Economizer Operation
•BAYSENS150
• Multi stage - 3 Heat/2 Cool Programmable
Thermostat
High Temperature Sensor (BAYFRST001*)
This sensor connects to the RTRM Emergency Stop Input
on the L TB and provides high limit “sh utdown” of the unit.
The sensor is used to detect high temperatures due to a
high thermal event 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 135ºF. The
supply air duct sensor (X1310004002) is set to open at
240ºF. The control can be reset after the temperature has
been lowered approximately 25ºF below the cutout
setpoint.
Evaporator Frost Control
ReliaTel™ Option
This input incorporates the Frostat™ control (FOS)
mounted in the indoor coil circuit and can be activated by
10 RT-SVX22J-EN
Page 11
General Information
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 1 continuous second 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.
Frostat is standard on multi-speed indoor motors and
single zone VAV products (SZVAV).
Electromechanical Option
This input incorporates the Frostat™ control (FOS)
mounted in the indoor coil circuit and can be activated by
opening a field supplied contact installed in series 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 during compressor operation, the
compressor for that circuit is immediately turned “Of f”. The
compressor will restart when the FOS closes.
Discharge Line Temp Switch (DLTS)
The DL TS is looped in series with HPC and LPC. It prevents
compressor from overheating (over 300 Fº dome temp) in
case of indoor fan failure (cooling) or outdoor fan failure
(heating).
Smoke Detector Sensor (Optional)
This sensor provides high limit “shutdown” of the unit and
requires a manual reset. The sensor is used to detect
smoke in the air conditioning or ventilation ducts.
Notes:
•The supply air smoke detector samples supply air. The
return and plenum air smoke detectors sample return
air. The smoke detectors are designed to shut off the
unit if smoke is sensed. This function is performed by
sampling the airflow enteri ng the unit at the return air
opening. Follow the instructions provided below to
assure that the airflow through the unit is sufficient for
adequate sampling. Failure to follow t hese instructions
will prevent the smoke detectors from performing its
design function.
•Airflow through the unit is affected by the amount of
dirt and debris accumulated on the indoor coil and
filters. To insure that airflow through the unit is
adequate for proper sampling by the return air smoke
detector, complete adherence to the maintenance
procedures, including recommended intervals
between filter changes, and coil cleaning is required.
•Periodic chec ks and maintenance procedures must be
performed on the smoke detector to insure that it will
function properly . For detailed instructions concerning
these checks and procedures, refer to the appropriate
section(s) of the smoke detector Installation and
Maintenance Instructions provided with the literature
package for this unit.
In order for the supply air smoke detector or return air
smoke detector to properly sense smoke in the supply air
stream or return air stream, the air velocity entering the
smoke detector unit must be between 500 and 4000 feet
per minute. Equipment covered in this manual will
develop an airflow velocity that falls within these limits
over the entire airflow range specified in the evaporator
fan performance tables.
Phase Monitor
This sensor monitors voltage between the 3 conductors of
the 3 phase power supply. Two LED lights are provided:
•The green light indicates that a balanced 3 phase
supply circuit is properly connected.
•The red light indicates that unit operation has been
prevented. There are two conditions that will prevent
unit operation:
• The power supply circuit is not balanced with the
proper phase sequence of L1, L2, L3 for the 3
conductors of a 3 phase circuit.
• The line to line voltage is not between 180 v olts and
633 volts.
Single Zone Variable Air Volume /
Displacement Ventilation (Optional)
This sensor offers full supply fan modulation across the
available airflow range. In addition to full supply fan
modulation, the unit controls the discharge air
temperature to a varying discharge air temperature
setpoint in order to maintain Space Temperature.
RT-SVX22J-EN11
Page 12
Unit Dimensions
TSC036-060E & THC036-037E UnitsTSC036-060E & THC036-037E Units
TSC072-120F, THC047-120E, & THC048-092F UnitsTSC072-120F, THC047-120E, & THC048-092F Units
Unit Clearances
Figure 1, p. 12 illustrates the minimum operating and
service clearances for either a single or multiple unit
Figure 1.Typical installation clearances for single & multiple unit applications
installation. These clearances are th e minimum distances
necessary to assure adequate serviceability, cataloged
unit capacity, an d 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.
12 RT-SVX22J-EN
Page 13
Figure 2.3-5 ton standard efficiency, 3 ton high efficiency
7
4444 MMMM
4444 MMMM
10381038 MMMM
10531053 MMMM
Note: All dimensions are in inches/millimeters.
Unit Dimensions
Figure 3.3-5 ton standard efficiency, 3 ton high efficiency - roof curb
Note: All dimensions are in inches/millimeters.
RT-SVX22J-EN13
Page 14
Unit Dimensions
CLEARANCE 36” (914 MM)
Figure 4.3-5 ton standard efficiency, 3 ton high efficiency - unit clearance and roof opening
Note: All dimensions are in inches/millimeters.
Figure 5.6, 7½ (single) ton standard efficiency, 4 - 5 ton high efficiency
Note: All dimensions are in inches/millimeters.
14 RT-SVX22J-EN
Page 15
Figure 6.6, 7½ (single) ton standard efficiency, 4 - 5 ton high efficiency - roo f curb
(2130 MM)
(356 MM)
Note: All dimensions are in inches/millimeters.
Unit Dimensions
Figure 7.6, 7½ (single) ton standard efficiency, 4 - 5 ton high efficiency - unit clearance and roof opening
Note: All dimensions are in inches/millimeters.
RT-SVX22J-EN15
Page 16
Unit Dimensions
(2130 MM)
(356 MM)
Figure 8.7½ ton (dual) - 10 ton standard efficiency, 6 & 7½ (microchannel) ton high efficiency
Note: All dimensions are in inches/millimeters.
Figure 9.7½ ton (dual) - 10 ton standard efficiency, 6 & 7½ (microchannel) ton high efficiency - roof curb
Note: All dimensions are in inches/millimeters.
16 RT-SVX22J-EN
Page 17
Unit Dimensions
Figure 10. 7½ ton (dual) - 10 ton standard efficiency, 6 & 7½ (microchannel) ton high efficiency - unit clearance and
roof opening
Note: All dimensions are in inches/millimeters.
Figure 11. 7½ (dehumidification) - 10 ton high efficiency
Note: All dimensions are in inches/millimeters.
RT-SVX22J-EN17
Page 18
Unit Dimensions
13/4”
(
44 MM
)
2”
(
51 MM
)
84 1/2”
(2146 MM)
83 7/8”
(2130 MM)
60 3/8”
(1534 MM)
59 7/8”
(
1521 MM
)
14”
(
356 MM
)
2”
(
51 MM
)
56 3/8”
(1432 MM)
34 3/8”
(873 MM)
34 3/8”
(873 MM)
18 1/2”
(470 MM)
18 1/2”
(470 MM)
1”
(
25 MM
)
1”
(
25 MM
)
1”
(
25 MM
)
65/8”
(
168 MM
)
80 1/2”
(2045 MM)
CL
EARANCE 18” (4
57 MM
)
FO
R
H
O
RIZO
NTAL
CLEARAN
C
E36”(914 MM)
FO
R
DO
WNFLOW
99 11/16”
(2532 MM)
63 3/16”
(1605 MM)
Figure 12. 7½ (dehumidification) - 10 ton high efficiency - roof curb
Note: All dimensions are in inches/millimeters.
Figure 13. 7½ (dehumidification) - 10 ton high efficiency- unit clearance and roof opening
Note: All dimensions are in inches/millimeters.
18 RT-SVX22J-EN
Page 19
Installation
Pre-Installation
WARNING
Fiberglass Wool!
Product contains fiberglass wool. Disturbing the
insulation in this product during installation,
maintenance or rep air 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, mask, long sleeves and pants when working
with products containing fiber glass w ool. Exposition t o
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.
Precautionary Measures
•Avoid breathing fiberglass dust.
•Use a NIOSH approved dust/mist respirator.
•Avoid contact with the skin or eyes. W ear 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 af fected areas gently with soap and
warm water after handling.
If an element has detached from its ceramic insulator,
carefully put it back into place.
Replace the heater elements if they present symptoms
noted in item 2 or 3 above.
Procedure
WARNING
Heavy Objects!
Ensure that all the lifting equipment used is properly
rated for the we ight of th e 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 whic h coul d 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 ser i ous injury and possi ble equipmen t
or property-only damage.
Figure 14. Corner weights
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.
Remove power to the unit and gain access to the electric
heat elements by removing the horizontal supply cover.
Visually inspect the heater elements for the following:
•Elements that are no longer secured to the white
ceramic insulator.
•Elements touching each other or touching metal.
•Severely kinked, drooping, or broken elements.
RT-SVX22J-EN19
Page 20
Installation
Table 1.Maximum unit & corner weights (lbs) and center of gravity dimensions (in.) - cooling models
(a) Weights are approximate.
(b)Corner weights are given for information only.
Model No.
Weights
(a)
Corner Weights
(b)
Center of Gravity
(in.)
Figure 15. Rigging and center of gravity
Table 2.Facto r y in sta lled options (fiops)/accessory net weights (lbs)
TSC036E-060E
THC036E/
THC037E
Net WeightNet WeightNet WeightNet WeightNet Weight
Accessory3-5 Ton4-5 Ton6-8½ Ton7½-10 Ton7½-10 Ton
Barometric Relief710101010
Belt Drive Option (3 phase only)3131———
Coil Guards1220202030
continued on next page
THC047E-067E
THC048E/F-
060E/F
(a),(b)
TSC072F-102F
THC072F
THC092F,
TSC120F
THC092E-
120E
20 RT-SVX22J-EN
Page 21
Installation
Table 2.Facto r y in sta lled options (fiops)/accessory net weights (lbs)
Economizer2636363636
Electric Heaters1530304040
Hinged Doors1012121212
Manual Outside Air Damper1626262626
Motorized Outside Air Damper2030303030
Novar Control88888
Oversized Motor588——
Powered Convenience Outlet3838383850
Powered Exhaust40408 08080
Reheat Coil1525——53
Roof Curb6178787889
Smoke Detector, Supply55555
Smoke Detector, Return77777
Stainless Steel Heat Exchanger46666
Through the Base Electrical813131313
Unit Mounted Circuit Breaker55555
Unit Mounted Disconnect55555
460V IDM
(a)Weights for options not listed are <5 lbs.
(b)Net weight should be added to unit weight when ordering factory-installed accessories.
(c) Apply weight with all 460V 17 SEER Two-Stage Cooling units.
(c)
2929---
(a),(b)
(continued)
Foundation
Horizontal Units
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. Re fer to T able 1, p. 20 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, ens ure the roof is strong enough
to support the combined unit and support structural
weight. Refer to Table 1, p. 20 for the unit operating
weights. If anchoring is required, anchor the unit to the
roof with hold-down bolts or isolators.
Check with a roofing contract or for proper w aterp roofing
procedures.
Ductwork
Figure 16, p. 21 to Figure 18, p. 22 illustrate the supply and
return air openings as viewed from the rear of the unit.
Figure 16. 3-5 ton standard efficiency units & 3 ton high
efficiency units - Horizontal supply & return
air openings
RT-SVX22J-EN21
Page 22
Installation
Supply
Return
3 7/8”
98 MM
9 3/8”
238 MM
19 1/4”
489 MM
16 3/4”
425 MM
4 3/4”
120 MM
32 1/4”
832 MM
27 5/8”
701 MM
Supply
Return
4 1/4”
108 MM
3/4-14 NPT DIA. HOLE
CONDENSATE DRAIN
32 1/4”
832 MM
Supply
Return
32 1/8”
816 MM
33”
838
MM
4”
102 MM
17 1/2”
444 MM
17 1/2”
444 MM
3 5/8”
92 MM
9 7/8”
251 MM
4 1/8”
104 MM
27 5/8”
THROUGH THE
BASE CONDENSATE
4 5/8”
119 MM
THROUGH THE
BASE ELECTRICAL
51 13/16”
42 3/16”
1072 MM
5 7/8”
149 MM
6 3/8”
163 MM
2 3/4”
71 MM
Figure 17.4-6/ 7½ (Microchannel) to n high efficiency
units and 6-10 t o n standard efficiency units Horizon tal suppl y & return air openings
Figure 18. 7½ (Dehumidification) - 10 ton high
efficiency units - Horiz ontal supply & return
air openings
Figure 20. 4-6/ 7½ (Microchannel) ton high efficiency
units and 6-10 ton standard efficiency units downflow supply & return air openings w/
through the base utilities
Figure 21. 7½ (Dehumidification) - 10 ton high efficiency
units - downflow supply & r et urn air openings
w/ through the base utilities
Figure 19. 3-5 ton standard efficiency units & 3 ton high
efficiency units - Downflow supply & r eturn
air openings w/ through the base utilities
22 RT-SVX22J-EN
Figure 19, p. 22 to Figure 21, p. 22 illustrate the supply and
return air openings in a downflow configuration.
Elbows with turning vanes or split ters are recommended
to minimize air noise due to turbulence and to reduce static
pressure.
When attac hing the ductwork to the unit, prov ide a w ater
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.
Page 23
Installation
Base Alignment Bracket
Table 3.Clearance required from duct to combustible
surfaces
Model Number
T(S/H)C036-60E0
THC037-67E0
TSC072F0
THC072F1
TSC090F1
TSC092F0
THC092E/THC092F1
TSC102F0
THC102E1
TSC120F***A0
TSC120F***B1
THC120E1
Clearance required from duct to
combustible surfaces (inches)
RoofCurb
Downflow
The roof curbs for these units consists of a "full perimeter"
enclosure to support the unit just inside of the unit base
rail. The 7½ - 10 ton high efficiency units contain a suppor t
base alignment rail and will extend past the end of the roof
curb as shown in figures below and to the right.
Before installing any roof curb, verify;
•it is the correct curb for the unit,
•it includes the necessary gaskets and hardware,
•the purposed installation location provides the
required clearance for proper operation,
•the curb is level and square. The top surface of the curb
must be true to assure an adequate curb-to-unit seal.
Step-by-step curb assembly and installation instructions
ship with each accessory roof curb kit. Follow the
instructions carefully to assure proper fit-up when the unit
is set into place.
Note: To assure proper condensate flow during
operation, the unit (and curb) must be level.
If the unit is elevated, a field constructed catwalk around
the unit is strongly recommended to provide easy access
for unit maintenance and service.
Recommendations for installing the Supply Air and R eturn
Air ductwork joining the roof curb are included in the curb
instruction booklet. Curb ductwork must be fab ricated and
installed by the installing contractor before the unit is set
into place.
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.
Figure 22. View for base to roof curb alignment
THC092-120E on 50" x 84" roof curb
WARNING
Combustible Materials!
Maintain proper clearance between the unit heat
exchanger, vent surfaces and combustible materials.
Refer to uni t nameplate an d installation instr uctions for
proper clearances. Improper clearances could result in
combustible mater ials catching on fire. Failure to
maintain proper clearances could result in death or
serious injury or property damage.
Verify that appropriate materials were used in the
construction of roof and ductwork. Combustible materials
should not be used in the construction of ductwork or roof
curb that is in close proximity to heater elements or any
hot surface. Any combustible material on the inside of the
unit base should be removed and replaced with
appropriate material.
RT-SVX22J-EN23
Page 24
Installation
Figure 23. View for base to roof curb alignment
THC092-120E on 60" x 84" roof curb
If a Curb Accessory Kit is not used:
•The ductwork can be attached directly to the factoryprovided flanges around the unit’s supply and return
air openings. Be sure to use flexible duct connections
at the unit.
•For “built-up” curbs supplied by others, gaskets must
be installed around the curb perimeter flange and the
supply and return air opening flanges.
Rigging
A Rigging illustration and Center-of-Gravity dimensional
data table is shown in Figure 15, p. 20. Refer to the typical
unit operating weights table before proceeding.
1. Remove all drill screws fastening wood protection to
metal base rail. Remove all screws securing wooden
protection to wooden top crate.
On 7½-10 ton high efficiency units, remove wire ties
from outdoor grill.
2. Remove Wooden Top Crate.
4. Install a lifting bar, as shown in Figure 15, p. 20, 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.
5. Test-lift the unit to ensure it is properly rigged and
balanced, make any necessary rigging adjustments.
Figure 24. Fork pockets (all units except 7½
(dehumidification)-10 ton high efficiency
units)
Figure 25. Fork pockets (7½ (dehumidification) -10 ton
high efficiency units)
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.
3. Rig the unit as shown in Figure 15, p. 20. 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.
24 RT-SVX22J-EN
NOTICE
6. Lift the unit enough to allow the removal of base fork
pocket protection components as shown in the
following figures. When 7½ (dehumidification)- 1 0 ton
high efficiency units are installed on smaller existing
roof curb (50"x 84") for replacement applications, do
not remove alignment bracket. This bracket helps
assure proper alignment of duct openings.
7. 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.
Page 25
Installation
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 unit
nameplate.
•Verify that the installation location of the unit will
provide the required clearance for proper operation.
•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.
•Install pitch p oc ket for power supply through building
roof. (If applicable)
•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 economizer installers
guide for proper position and setup.
•Install all access panels.
Note: Failure to use recommended sealant could result in
unit performance loss.
If a unit is to be converted to a Horizontal discharge, the
following conversion must be performed:
1. Remove RETURN and SUPPLY duct covers.
2. Locate supply cover. Apply ¼ in. (6mm.) continuous
bead of 500°F RTV sealant to the flange as shown.
Figure 26. Supply duct cover
RTV Sealant
3. Position duct cover as shown, rotate 90 degrees to
allow entrance into supply opening.
4. Slide duct covers into duct openings until inward edge
of duct cover engages with the 2 retaining clips on the
duct flanges. Secure the outward edge of each duct
cover with 2 screws.
5. Slide RETURN DUCT COVER (insulation side up) into
supply opening until inward edge of du ct cover
engages with the 2 retaining clips on the duct flange.
Secure outward edge of the duct co ver with two
screws.
Note: Certain unit/electric heater combinations require a
limit switch change out for horizontal airflow
applications. Refer to the following instructions to
determine if this process is required for the unit
undergoing installation.
Horizontal Discharge Conversion
(6 Through 10 Ton Units)
Temperature Limit Switch Usage for
Electric Heat Units
Units are factory shipped in the downflow discharge
configuration but can be field converted to a horizontal
discharge configuratio n. Som e, but not all units requ ire a
different TCO-A limit switch, which is wire tied near the
terminal block in the heater compartment if horiz o ntal
discharge configuration is used.
Horizontal Discharge Conversion
(3 Through 5 Ton Units)
Note: 3 - 5 ton units supply cover to supply opening and
return cover to return opening.
Supplies Needed by Installer for Conversion: 3 oz. tube of
High Temperature RTV sealant. (500°F / 260°C: Similar to
Dow Corning 736)
RT-SVX22J-EN25
Note: 6 - 1 0 ton units the supply cover to return opening
& return cover to supply opening.
Supplies Needed by Installer for Conversion: 3 oz. tube of
high Temperature RTV sealant. (500°F / 260°C: Similar to
Dow Corning 736)
Note: Failure to use recommended sealant could result in
unit performance loss.
If a unit is to be converted to a Horizontal discharge, the
following conversion must be performed:
1. Remove RETURN and SUPPLY duct covers.
2. Place SUPPLY DUCT COVER over down-flow return
opening. (insulation side down)
3. Using self-drilling screws, (or screws removed from
duct cover), screw through dimples to attach DUCT
COVER to base.
Page 26
Installation
RTV Sealant
Downow application
Horizontal application
Cap assembly
with insulation
Remove and discard this tube
for horizontal conversion
Cap assembly
with insulation
Secure with screw
Insulation side
down
Supply duct cover
Insulation side up
Return duct
cover
Figure 27.Supply duct cover
Supply Duct Cover
Screw into 4
dimples on top
edge
4. On original RETURN DUCT COVER, apply ¼”(6mm.)
continuous bead of 500°F RTV sealant around flange
(opposite insulation side), as shown.
Figure 28. Return duct cover
5. Slide RETURN DUCT COVER (insulation side up) into
supply opening until inward edge of duct cover
engages with the 2 retaining clips on the duct flange.
Secure outward edge of the duct cover with two
screws.
Note: If unit is equipped with Return Air Smoke Detector,
refer to field conversion instructions for horizontal
discharge before installing return air duct.
Note: If unit is equipped with Discharge Air Sensing
option refer to the following figure for proper tube
positioning based on unit tonnage.
Figure 29. Discharge air sensor
Note: Certain unit/electric heater combinations require a
limit switch change out for horizontal airflow
applications. Refer to the following instructions to
determine if this process is required for the unit
undergoing installation.
Figure 30. Supply & return openings
6. After completing installation of the duct covers for
horizontal discharge, proceed to TCO-A instructions.
TCO-A Instructions
If the unit being installed is listed in the following table and
is equipped with the corresponding model number of
factory installed electric heater package in the table, the
limit control TCO-A must be replaced with the extra limit
control shipped in the heater compartment. Replace TCOA following the instructions in steps 1 through 3 below. If
the unit being installed does not have a factory installed
electric heater package or is equipped with a factory
installed electric heater model that does not correspond to
any in this table, skip steps 1 through 3 and go on to next
step in the installation process.
1 . Remove the heat er section access panel and open the
electric heater dead front panel.
2. TCO-A is the limit control located in the central part of
the heater mounting plate and that is located on the
bottom of the two heater element assemblies. To
replace this device, first remove the two wires
connected to the terminals. Next, remove the two
screws which secure it to th e heater element mounting
plate. Once TCO-A has been removed form the heater
element mounting plate, discard this device.
3. Obtain the replacement TCO-A which is secured by a
wire tie near the electric heater terminal block in the
heater compartment. Attach it to the heater element
mounting plate with the two screws that were removed
in step 2 above. Connect the two wires that were unhooked in step 2 to the terminals on the new TCO-A.
Refer to the heater package wiring diagram to assure
that the wiring is connected properly.
4. Close the electric heater dead front pane l and repla ce
heat section access panel.
26 RT-SVX22J-EN
Page 27
Installation
Table 4.TCO-A replaced for horizontal duct
configuration
Unit Model
Number
TSC120F4, THC092F
TSC120FW
THC072F4BAYHTRU427, 436Center
TSC090F4BAYHTRW427, 436Center
TSC090FWBAYHTRWW27, W36 Center
Electric Heater
Model NumberTCO-A location
BAYHTRA418, 427,
436, 454
BAYHTRAW18A, 36A,
54A
Right
Right
Figure 31. TCO-A location
Figure 32. Downflow view
3. Lift the tube and bracket from the downflow duct
opening. Rotate the tube and bracket assembly 180
degrees ensuring that the holes on the copper sensing
tube face away from the unit and face the return air
ductwork. Refer to horizontal views below.
Figure 33. Horizontal view 1
Return Air Smoke Det ector
The factory installed Return Air Smoke Detector is
installed in the downflow discharge position. No
additional field setup is required.
If a unit is to be converted to horizontal di scharge, the
following conversion must be performed:
1. If the unit has an economizer , it mu st be pulled out in
the operating position.
2. Remove the 3 screws from the mounting brackets.
Refer to downflow view for screw locations.
RT-SVX22J-EN27
Page 28
Installation
4
2
Figure 34. Horizontal view 2
Note: Check to insure that the flexible tubing lies flat on
the base pan surface.
4. Slide the top bracket down the copper sensing tube.
For TSC036E-060E, and THC036-037E units insert the
tab on the left side into the slot on the indoor coil blo ck
off and secure the right side of the bracket with one of
the 3 screws removed in step 2. Refer to Figure 33,
p. 27. For THC047E-120E, THC048F-092F, and TSC072F -
120F units secure the tab on left side to the indoor coil
block off with one of the screws removed in step 2 and
secure the right side of the bracket with one of the
screws removed from the access panel. Refer to
Figure 34, p. 28.
5. Using the remaining 2 screws removed in step 2,
secure the bottom bracket. Refer to Figure 33, p. 27.
Note: Larger diameter holes on bottom bracket line up
with the dimples on the rear panel. The smaller
diameter holes line up with the screw holes in the
rear panel.
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, y ou MUST follo w requir ements 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.
Failur e t o f ollo w this instructions could result in death or
serious injuries.
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.
Electric Heat Requirements
•Verify that the power supply complies with the electric
heater specifications on the unit and heater nameplate.
•Inspect the heater junction box and control panel;
tighten any loose connections.
•Check electric heat circuits for continuity.
Low Voltage Wiring
(AC & DC) Requirements
•Install the zone thermostat, with or without switching
subbase.
•Connect properly sized control wiring to the proper
termination points between the zone thermostat and
the unit control panel.
Main Electrical Power Requirements
WARNING
Hazardous Voltage w/Capacitors!
Disconnect all electric power, including remote
disconnects and discharge all motor start/run
capacitors before servicing. Follow proper lockout/
tagout procedures to ensure the power cannot be
inadvertently energized. Verify with an appropriate
voltmeter that all capacit ors ha ve discharged. F ail ur e t o
disconnect power and discharge capacitors before
servicing could result in death or serious injury.
For additional information regarding the safe discharge
of capacitors, see PROD-SVB06A-EN
28 RT-SVX22J-EN
Condensate Drain Configuration
An evaporator condensate drain connection is provided
on each unit. Re fer to Figure 16, p. 21 and Figure 17, p. 22
for the appropriate drain location.
The condensate drain pan is factory installed to drain
condensate to the back side of the unit. See Figure 16, p. 21
and Figure 17, p. 22. It can be converted to drain
condensate out the front side of the unit or through the
base.
To convert drain condensate out the front of unit:
1 . Remove evaporator access panel and supply air access
panels.
Page 29
Installation
2. Remove the support panel that the condensate drain
pan exits through.
3. Slide the condensate drain pan out of the unit and
rotate 180°.
4. Slide the condensate drain pan back into the unit, align
the drain with the grommeted opening in the rear
support panel and push until the co upling is seated in
the grommet.
5. Replace the front support panel by aligning the panel
with tabs in the raceway. Align the condensate drain
pan support in the grommeted hole as the panel is put
in place.
6. Replace evaporator access panel and supply air access
panels.
To convert drain condensate through the base
of unit:
1 . Remove evaporator access panel and supply air access
panels.
2. Remove the support panel that the condensate drain
pan exits through.
3. Slide the condensate drain pan out of the unit.
4. Place on a level surface in the position it was removed
from the unit.
5. Remove the plug knockout in the bottom of the
drainpan to convert it to th ro ug h the base drainag e.
6. Plug the original condensate drain opening with a field
supplied 3/4" NPT plug.
7. Slide the condensate drain pan bac k into the unit, align
the drain support with the grommeted opening in the
rear support panel and push until the suppor t is seated
in the grommet.
8. Replace the front support panel by aligning the panel
with tabs in the raceway . Align the plugged condensate
drain pan coupling in the grommeted hole as the panel
is put in place.
9. Replace evaporator access panel and supply air access
panels.
A condensate trap must be installed at the unit due to the
drain connection being on the “negative pressure” side of
the fan. Install the P -T rap using the guidelines in Figure 35,
p. 29.
A condensate drain line must be connected to the P-Tr ap.
Pitch the drain lines at least 1/2 inch for every 10 feet of
horizontal run to assure proper condensate flow. Do not
allow the horizontal run to sag causing a possible doubletrap condition which cou ld result in cond en sate backup
due to “air lock”.
Figure 35. Condensate trap installation
38.1
Filter Installation
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
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, y ou MUST follo w requir ements 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.
An overall dimensional layout for the 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 following
guidelines.
Ve rify that the power supply available is compatible with
the unit’s nameplate ratings. The available supply power
must be within 10% of the rated voltage stamped on the
nameplate. Use only copper conductors to connect the
power supply to the unit.
NOTICE:
Use Copper Conductors Only!
Unit terminals ar e not designed t o accept other types of
conductors. Failure to use copper conductors could
result in equipment damage.
RT-SVX22J-EN29
Important: If the unit is not equipped with an optional
factory installed non-fused disconnect
Page 30
Installation
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
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.
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.
box. Apply Black Gasket around conduit plate on all
4 sides after installation to prevent air leakage from
the building entering the electrical enclosures.
Note: Seal between wiring and conduit with Blac k Gasket
or weather proof sealer to prevent air leakage from
the building entering the electrical enclosures. Also
seal around conduit and wiring at all roof and curb
penetrations.
Figure 36. All units except 8½-10 ton high efficiency, and
7½ ton high efficiency with hot gas reheat
dehumidification.
Standard Wiring
Location of the applicable electrical service entrance is
illustrated in “Unit Dimensions,” p. 12. Complete the unit’ s
power wiring connections at Compressor Contactor # 1
(CC1) inside the unit control panel. Refer to the customer
connection diagram that is shipped with the unit for
specific termination points
Provide proper grounding for the unit in accordance with
local and national codes.
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 point s. The
termination points, depending on the customer option
selected would be a factory mounted non-fused
disconnect switch (UDC) or circuit breaker (UCB). If neither
a factory mounted non-fused disconnect switch (UDC) or
circuit breaker (UCB) was factory mounted, field wiring
connections should be terminated in the control box at
Compressor Contactor # 1 (CC1).
Provide proper grounding for the unit in accordance with
local and national codes.
Note: Black Gasket is shipped from the factory and is
located in the literature Ship With bag in the control
Figure 37.8½-10 ton high efficiency, and 7½ ton high
efficiency with hot gas reheat
dehumidification.
SEAL BETWEEN
WIRING AND
CONDUIT WITH
WEATHER PROOF
SEALER TO PREVENT
AIR LEAKAGE
CONTROL WIRING
CONDUIT
BLACK GASKET
FIELD POWERED
CONVENIENCE OUTLET
CONDUIT
CONTROL WIRING
CONDUIT
Field Installed Control Wiring
An overall layout of the various control options available
with the required number of conductors for each control
device is illustrated in Figure 52, p. 38.
30 RT-SVX22J-EN
Page 31
Installation
Control Power Transformer
The 24 volt control power transformers are to be used only
with the accessories called out in this manual.
T ran sformers rated grea ter than 50 VA are equipped with
internal circuit breakers. If a circuit breaker trips, turn “Off”
all power to the unit before attempting to reset it.
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.
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 Table 5, p. 31 or T able 6, p. 31 for
AC conductor sizing guidelines, and;
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 may
cause component failure due to insufficient AC
voltage supply.
Note: Be sure to c h eck all loads and conductors for
grounds, shorts, and mis-wiring.
3. Do not run the AC low voltage wiring in the same
conduit with the high voltage power wiring.
4. Route low voltage wiring per illustrations on page 33.
Table 5.Electromechanical thermostat 24V AC
conductors with ReliaTel units
Distance from Unit to
ControlRecommended Wire Size
Controls using DC Analog
Input/Outputs (Standard Low Voltage
Multi conductor Wire)
Before installing any connecting wiring between the u nit
and components utilizing a DC analog input\output signal,
refer to “Unit Dimensions,” p. 12 for the electrical access
locations provided on the unit.
•Table 7, p. 31 lists the conductor sizing guidelines that
must be followed when interconnecting the DC binary
output devices and the system components utilizing a
DC analog input\output signal to the unit.
Note: Resistance in excess of 2.5 ohms per conductor can
cause deviations in the accuracy of the controls.
Note: Ensure that the wiring between controls and the
unit’ s termination point does not exceed two and a
half (2.5) ohms/conductor for the length of the run.
•Do not run the electrical wires transporting DC signals
in or around conduit housing high voltage wires.
•Route low voltage wiring per illustrations on page33.
Note: If digit 9 in the unit model number equals "E"
(Electro Mechanical Control), accessory relay
BAY24X042 is required if the thermostat does not
energize the fan circuit in the heating mode.
Table 7.Zone sensor module wiring
Distance from Unit to
ControlRecommended Wire Size
Figure 38. ReliaTel conventional thermostat field wiring
diagrams
RTRM
Figure 39. Typical field wiring diagrams for Electro
Mechanical Thermostat
Figure 41. ReliaTel relative humidity sensor
(dehumidification option)
Figure 42. ReliaTel humidistat (dehumidification
option)
Figure 40. ReliaTel options module
32 RT-SVX22J-EN
Page 33
Installation
Figure 43. Electro mechanical control customer low voltage routing (all units except 8½ - 10 ton high efficiency, and
7½ ton high efficiency with hot gas reheat dehumidification.)
Figure 44. ReliaTel control customer low voltage routing (all units except 7½ (dehumidification) - 10 ton high
efficiency)
RT-SVX22J-EN33
Page 34
Installation
Figure 45. ReliaTel (without TBUE) control customer wire routing (7½ (dehumidification) - 10 ton high efficiency)
Figure 46. ReliaTel (with TBUE) control customer wire routing (7½ (dehumidification) -10 ton high efficiency)
34 RT-SVX22J-EN
Page 35
Installation
Figure 47. Electromechanical (without TBUE) control customer wire routing (7½ (dehumidification) - 10 ton high
efficiency)
Figure 48. Electromechanical (with TBUE) control customer wire routing (7½ (dehumidification) - 10 ton high
efficiency)
RT-SVX22J-EN35
Page 36
Installation
Smoke Detector Customer Low
Voltage Wiring
When interlocking System Sensor smoke detectors
together, all of the detectors must be powered from the
same power supply. If the smoke detectors are powered
up by different power supplies, harmonics are set up and
will fry the boards in some, if not all, of the detectors.
If multiple smoke detectors are required, all detectors
must be disconnected from the HVAC un it pow er sup ply
and connected together from another single source
supply.
Note: Do not interconnect an y smoke detectors together
that have separate power supplies. Do not exceed
ten smoke detectors on one power supply.
Note: Multiple System Sensor smoke detectors are
connected together using terminals 1 and 12 on
each detector.
Figure 49. Up to 5 HVAC units
If you have supply and return smoke detectors in all HVAC
units, you can connect a maximum of 5 HVAC units (10
detectors) up to one power supply. See the following field
wiring example.
Figure 50. Up to 10 HVAC units
If you have more than 5 HVAC units, you can
connect all the supplies together on one power
supply (up to 10 HVAC units), and all the returns
together (up to 10 HV A C units) on another power
supply. See the following field wiring example.
36 RT-SVX22J-EN
Space Temperature Averaging
(ReliaTel™ only)
Space temperature averaging is accomplished by wiring a
number of remote sensors in a series/parallel circuit.
Using the BAYSENS016* or BAYSENS077*, at least four
sensors are required to accomplish space temperature
averaging.
•Example #1 illustrates two series circuits with two
sensors in each circuit wired in parallel. The square of
any number of remote sensors is required.
•Example #2 illustrates three sensors squared in a
series/parallel circuit. Using BAYSENS077*, two
sensors are required to accomplish space temperature
averaging.
Example #3 illustrates the circuit required for this sensor.
Table 8, p. 39 lists the temperature versus resistance
coefficient for all sensors.
Page 37
Figure 51. Examples
Installation
RT-SVX22J-EN37
Page 38
Installation
BAYSENS075*
BAYSENS075*
BAYSENS119*
BAYSENS110*
BAYSENS108*
BAYSENS106*
BAYSENS073*BAYSENS074*
BAYSENS075*
ASYSTAT669A
OPTIONAL REMOTE SENSOR
Figure 52. Typica l field wiring diagrams for optional controls (ReliaTel only)
38 RT-SVX22J-EN
Page 39
Table 8.Temperature vs. resistance
Temperature
Degrees F°Degrees C°
-20°-28.9°170.1 K - Ohms
-15°-26.1° 143.5 K - Ohms
-10°-23.3°121.4 K - Ohms
-5°-20.6°103.0 K - Ohms
0°-17.8°87.56 K - Ohms
5°-15.0°74.65 K - Ohms
10°-12.2°63.80 K - Ohms
15°-9.4°54.66 K - Ohms
20°-6.7°46.94 K - Ohms
25°-3.8°40.40 K - Ohms
30°-1.1°34.85 K - Ohms
35°1.7°30.18 K - Ohms
40°4.4°26.22 K - Ohms
45°7.2°22.85 K - Ohms
50°10.0°19.96 K - Ohms
55°12.8°17.47 K - Ohms
60°15.6°15.33 K - Ohms
65°18.3°13.49 K - Ohms
70°21.1°11.89 K - Ohms
75°23.9°10.50 K - Ohms
80°26.7°9.297 K - Ohms
85°29.4°8.247 K - Ohms
90°32.2°7.330 K - Ohms
95°35.0°6.528 K - Ohms
Nominal
Resistance
Installation
RT-SVX22J-EN39
Page 40
Pre-Start
Use the checklist provided below in conjunction with the
“General Unit Requirements” checklist to ensure that the
unit is properly installed and ready for operation.
WARNING
Hazardous Voltage w/Capacitors!
Disconnect all electric power, including remote
disconnects and discharge all motor start/run
capacitors before servicing. Follow proper lockout/
tagout procedures to ensure the power cannot be
inadvertently energized. Verify with an appropriate
voltmeter that all capacit ors ha ve disc har g ed. F ailur e t o
disconnect power and discharge capacitors before
servicing could result in death or serious injury.
For additional information regarding the safe discharge
of capacitors, see PROD-SVB06A-EN
•Check all electrical connections for tightness and
“point of termination” accuracy.
•V erify that the condenser airflow will be unobstructed.
•Verify that the condenser fan and indoor blower turn
freely without rubbing and are properly tightened on
the shafts.
•Check the supply fan belts for proper tension and the
fan bearings for sufficient lubrication. If the belts
require adjustment, or if the bearings need lubricati ng,
refer to the maintenance section of this manual for
instructions.
•V erify that a condensate trap is installed and the piping
is properly sized and pitched.
•V erify that the correct size and number of filters are in
place.
•Inspect the interior of the unit for tools and debris and
install all panels in preparation for starting the unit.
Voltage Imbalance
Three phase electrical power to the unit must meet
stringent requirements for the unit to operate properly.
Measure each leg (phase-to-phase) of the power supply.
Each reading must fall within the utilization range stamped
on the unit nameplate. If any of the readings do not fall
within the proper tolerances, notify the power company to
correct this situation before operating the unit.
Excessive three phase voltage imbalance between phases
will cause motors to overheat and eventually fail. The
maximum allowable voltage imbalance is 2%. Measure
and record the voltage between phases 1, 2, and 3 and
calculate the amount of imbalance as follows:
AV (Average Voltage)=
V1, V2, V3 = Line Voltage Readings
VD = Line Voltage reading that deviates the far thest from
the average voltage.
Volt 1 + Volt 2 + Volt 3
3
Example: If the voltage readings of the supply power
measured 221, 230, and 227, the average volts would be:
221 + 230 + 227
3
VD (reading farthest from average) = 221
The percentage of Imbalance equals:
100 x 226 - 227
226
The 2.2% imbalance in this example exceeds the
maximum allowable imbalance of 2.0%. This much
imbalance between phases can equal as much as a 20%
current imbalance with a resulting increase in motor
winding temperatures that will decrease motor life. If the
voltage imbalance is over 2%, notify the proper agencies
to correct the voltage problem before operating this
equipment.
= 226 Avg.
= 2.2%
Electrical Phasing (Three Phase
Motors)
The compressor motor(s) and the supply fan motor are
internally connected for the proper rotation when the
incoming power supply is phased as A, B, C.
Proper electrical supply phasing can be quickly
determined and corrected before star ting the unit by using
an instrument such as an Associated Research Model 45
Phase Sequence Indicator and following the steps below:
WARNING
Hazardous Voltage w/Capacitors!
Disconnect all electric power, including remote
disconnects and discharge all motor start/run
capacitors before servicing. Follow proper lockout/
tagout procedures to ensure the pow er cannot be
inadvertently energized. Verify with an appropriate
voltmeter that all capacitors have discharged. Failure to
disconnect power and discharge capacitors before
servicing could result in death or serious injury.
For additional information regarding the safe discharge
of capacitors, see PROD-SVB06A-EN
% Voltage Imbalance=
40 RT-SVX22J-EN
100 x AV - VD
AV
where;
•T urn the field supplied disconnect switch that provides
power to the main power terminal block or to the
Page 41
Pre-Start
“Line” side of the optional factory mounted disconnect
switch to the “Off” position.
•Connect the phase sequence indicator leads to the
terminal block or to the “Line” side of the optional
factory mounted disconnect switch as follows;
• Black (phase A) to L1
• Red (phase B) to L2
• Yellow (phase C) to L3
•Close the field supplied main power disconnect switc h
or circuit protector switch that provides the supply
power to the unit.
WARNING
Live Electrical Components!
During installation, testing, servicing and
troubleshooting of this produ ct, it ma y be necessary t o
work with live electrical components. Have a qualified
licensed electrician or other individual who has been
properly trained in handling live electrical components
perform these tasks. Failure to follow all electrical
safety precautions when exposed to live electrical
components could result in death or serious injury.
To prevent injury or death from electrocution, it is the
responsibility of the technician to recogniz e this hazard
and use extreme care when performing service
procedures with the electrical power energized.
•Observe the ABC and CBA phase indicator lights on the
face of the sequencer. The ABC indicator light will glow
if the phase is ABC. If the CBA indicator light glows,
open the disconnect switc h or circuit protection switc h
and reverse any two power wires.
•Restore the main electrical power and recheck the
phasing. If the phasing is cor rect, open the disconnect
switch or circuit protection switch and remove the
phase sequence indicator.
Compressor Crankcase Heaters (Optional)
Each compressor can be equipped with a crankcase heater
(On some units the crankcase heater comes standard). The
proper operation of the crankcase heater is important to
maintain an elevated compressor oil temperature during
the “Off” cycle to reduce oil foaming during compressor
starts.
Oil foaming occurs when refrigerant condenses in the
compressor and mixes with the oil. In lower ambient
conditions, refrigerant migration to the compressor could
increase.
When the compressor starts, the sudden reduction in
crankcase pressure causes the liquid refrigerant to boil
rapidly causing the oil to foam. This condition could
damage compressor bearings due to reduced lubrication
and could cause compressor mechanical failures.
Before starting the unit in the “Cooling” mode, set the
system switch to the “Off” position and turn the main
power disconnect to the “On” position and allow the
crankcase heater to operate a minimum of 8 hours.
Before closing the main power disconnect switch, insure
that the “System” selection switch is in the “ Of f” position
and the “Fan” selection switch is in the “Auto” position.
Close the main power disconnect switch and the unit
mounted disconnect switch, if applicable.
Note: Upon closing main power disconnect and the unit
mounted disconnect switch or circuit breaker, the
phase monitor will verify proper phasing. If LED on
face of the monitor is red, correct supply power
fault.
WARNING
Live Electrical Components!
During installation, testing, servicing and
troubleshooting of this product, it may be necessary to
work with live electrical components. Have a qualified
licensed electrician or other individual who has been
properly trained in handling live electrical components
perform these tasks. F ailure t o follow all electr ical safety
precautions when exposed to live electrical
components could result in death or serious injury.
To prevent injury or death from electrocution, it is the
responsibility of the technician to recognize this hazard
and use extreme care when performing service
procedures with the electrical power energized.
ReliaTel™ Controls
Upon power initialization, the RTRM performs selfdiagnostic checks to insure that all internal controls are
functional. It also checks the configuration parameters
against the components connected to the system. The
Liteport LED located on the RTRM module is turned “On”
within one second of power-up if internal operation is
okay.
Use one of the following “T est” procedure to bypass some
time delays and to start the unit at the control panel. Each
step of unit operation can be activated individually by
temporarily shorting across the “T est” terminals for two to
three seconds. The Liteport LED located on the RTRM
module will blink when the test mode has been initiated.
The unit can be left in any “Test” step for up to one hour
before it will automatically terminate, or it can be
terminated by opening the main power disconnect switch.
Once the test mode has been termin ated, the Liteport LED
will glow continuously and the unit will revert to the
“System” control.
RT-SVX22J-EN41
Page 42
Pre-Start
Table 9.Service test guide for component operation
Test StepModeFanEcon
FanOn
1
Minimum
Ventilation
Economizer
2
Test Open
3
(e)
4
5 (e)
6 (e)ReheatOnMinimumOnO nOffOff33K
7 (e)
8 (e)
(a)The exhaust fan will turn on anytime the economizer damper position is equal to or greater than the exhaust fan setpoint.
(b)The PWM Output is in reference to the user selected maximum unit fan speed.
(c) Regardless of the Economizer Mode configuratio n, the unit will run the Supp ly Fan at the minimum spee d during the Economizer step of the Service Te st.
(d)The condenser fans will operate any time a compressor is ‘On’ providing the outdoor air temperatures are within the operating values.
(e) Steps for optional accessories and non-applicable modes in unit will be skipped.
(f) Units with Enhanced Dehumidification only will not perform this step during Service Test.
Cool
Stage 1
Cool
Stage 2
Cool
Stage 3
Heat
Stage 1
Heat
Stage 2
OnSelectableOffOffOffOff
OnOpenOffOffOffOff3.3K
On
On
On
OnMinimumOffOffOnOff10K
OnMinimumOffOffOnOn15K
(a)
Minimum
Position
Setpoint 0%
Minimum
Position
Minimum
Position
Minimum
Position
Comp 1 Comp 2Heat 1Heat 2Resistance
OffOffOffOff
2.2KΩ50%low
Ω50%
(d)
On
On (d)On (d)OffOff6.8K
On (d)On (d)OffOff8.2K
OffOffOff4.7KΩ82%low
Ω100%
Ω100%High
Ω100%
Ω100%High
Ω100%High
PWM
Output
Multi-Speed Fan
(b)
(c)
High (2-step cooling)
Low (3-step cooling)
(f)
Output
low
High
Test Modes
There are three methods in which the “T est” mode can be
cycled at LTB-Test 1 and LTB-Test 2.
•Step Test Mode - This method initiates the different
components of the unit, one at a time, by temporarily
shorting across the two test terminals for two to three
seconds.
For the initial start-up of the unit, this method allows
the technician to cycle a component “ On” and have up
to one hour to complete the chec k.
•Resistance Test Mode - This method can be used for
start-up providing a decade box for variable resistance
outputs is available. This method initiates the different
components of the unit, one at a time, when a specific
resistance value is placed across the two test
terminals. The unit will remain in the specific test mode
for approximately one hour even though the
resistance is left on the test terminals.
•Auto T est Mode - This method is not recommended for
start-up due to the short timing between individual
Electromechanical Controls
Test Procedure
See unit schematic for correct wire numbers.
Fan Test and Minimum Ventilation
Connect red thermostat wire (R) to black thermostat wire
(G).
Economizer Cooling
Connect a jumper wire across OTS on Economizer Control
(ECA).
Connect red thermostat (R) wire to yellow thermostat wire
(Y1).
Cool 1
Connect red thermostat wire (R) to yellow thermostat wire
(Y1).
Cool 2
Connect red thermostat wire (R) to yellow thermostat wire
(Y2).
component steps. This method initiates the different
components of the unit, one at a time, when a jumper
is installed across the test terminals. The unit will start
the first test step and change to the next step every 30
Heat 1
Connect red thermostat wire (R) to brown thermostat wire
(W1).
seconds.
At the end of the test mode, control of the unit will
automatically revert to the applied “System” control
method.
Heat 2
Connect red thermostat wire (R) to brown thermostat wire
(W2).
For unit test steps, test modes, and step resistance values
to cycle the various components, refer to Table 9, p. 42.
42 RT-SVX22J-EN
Page 43
Start-Up
Verifying Proper Air Flow
WARNING
Live Electrical Components!
During installation, testing, servicing and
troubleshooting of this product, it may be necessary to
work with live electrical components. Have a qualified
licensed electrician or other individual who has been
properly trained in handling live electrical components
perform these tasks. F ailure to f ollow all electr ical saf ety
precautions when exposed to live electrical components
could result in death or serious injury.
Units with 5-Tap Direct Drive Indoor Fan
Much of the systems performance and reliability is closely
associated with, and dependent upon having the proper
airflow supplied both to the space that is being
conditioned and across the evaporator coil.
The indoor fan motor is factory wired to operate on speed
tap 1 in the cooling and heating mode for electric/electric
units. For Gas/Electric units, the motor is factory wired to
operate on speed tap 1 during cooling. For 3 & 4 ton Gas/
Electric units operating in heat mode, the minimum sett ing
is Tap 4.
For these units, a separate tap terminal is provided to
change speeds automatically between heating and
cooling. The motor can be rewired for different speed
settings should the application require it. Refer to the
wiring diagram that shipped in the unit and the unit fan
performance tables in the Service Facts.
The indoor fan motors are specifically designed to operate
within the BHP parameters listed in the fan performance
tables of the unit Service Facts.
When verifying direct drive fan performanc e, the tables
must be used somewhat differently than those of belt
driven fans. Fan performance diagnostics can be easily
recognized when these tables are used correctly.
Before starting the SERVICE TEST, set the minimum
position setpoint for the economizer to 0% using the
setpoint potentiometer located on the Economizer Control
(ECA), if applicable.
ReliaTel Control: Using the Service Test Guide in
Table 9, p. 42, momentarily jump across the Test 1 & T est
2 terminals on L T B1 one time to start the Minimum
Ventilation Test.
Electro Mechanical Control: Using the Service Test
Guide perform the proper test mode connections.
With the fan operating properly, determine the total
system external static pressure (inches w.c.) by the
following method (ReliaTel/Electromechanical):
1 . Measure the supply and return duct static pressure and
sum the resulting absolute values,
2. Use the accessory pressure drop table in the Service
Facts, to calculate the total static pressure drop for all
of the accessories installed on the unit; i.e., curb,
economizer, etc.
Note: Accessory static pressure drop is based on desired
CFM and may not be actual static pressure drop.
3. Add the total accessory static pressure drop (step 2) to
the duct external static pressure (step 1). The sum of
these two values represents the total system external
static pressure.
Using the Fan Performance Tables in the Service Facts,
look up the selected speed tap setting and match the
measured ESP to determine the approximate CFM.
If the required CFM is too low, (external static pressure is
high) do one or both of the following and repeat
procedure:
a. Relieve supply and/or return duct static.
b. Change indoor fan speed tap to a higher value
If the required CFM is too high, (external static pressure is
low), do one or both of the following and repeat
procedure:
c. Increase supply and/or return duct static.
d. Change indoor fan speed tap to a lower value.
Note: Minimum settin g for units with gas or electric heat
is 320 CFM per ton. For 3 & 4 ton gas Heat units
operating in heating mode the heat speed set
cannot be lower than speed Set 4.
4. To stop the SERVICE TEST, turn the main power
disconnect switch to the "Off" position or proceed to
the next component start-up procedure.
Units with Belt Drive Indoor Fan
Much of the systems performance and reliability is closely
associated with, and dependent upon having the proper
airflow supplied both to the space that is being
conditioned and across the evaporator coil.
The indoor fan speed is c hanged by opening or closing the
adjustable motor sheave.
Before starting the SERVICE TEST, set the minimum
position setpoint for the economizer to 0% using the
setpoint potentiometer located on the Economizer Control
(ECA), if applicable.
ReliaTel Control: Using the Service Test Guide in
Table 9, p. 42, momentarily jump across the Test 1 & Test
2 terminals on LTB1 one time to start the Minimum
V entilation T e st.
Electro Mechanical Control: Using the Service Test
Guide perform the proper test mode connections.
RT-SVX22J-EN43
Page 44
Start-Up
Once the supply fan has started, c hec k for proper rotation.
The direction of rotation is indicated by an arrow on the fan
housing.
With the fan operating properly, determine the total
system airflow (CFM) by (ReliaTel/Electromechanical):
1. Measuring the actual RPM.
2. Measure the amperage at the supply fan contactor and
compare it with the full load amp (FLA) rating stamped
on the motor nameplate.
a. Calculate the theore tical BHP using (Actual Motor
Amps/ Motor Nameplate Amps) X Motor HP.
b. Using the fan performance tables in the unit Service
Facts, plot the actual RPM (step 1) and the BHP (step
2a) to obtain the operating CFM.
3. If the required CFM is too low, (external static pressure
is high causing motor HP output to be below table
value),
a. Relieve supply and/or return duct static.
b. Change indoor fan speed and repeat steps 1 and 2.
• T o Increase Fan RPM; Loosen the pulley adjustment
set screw and turn sheave clockwise.
• To Decrease Fan RPM; Loosen the pulley
adjustment set screw and turn sheave
counterclockwise.
• If the required CFM is too high, (external static
pressure is low causing motor HP output to be
above table value), change indoor fan speed and
repeat steps 1 and 2.
• To stop the SERVICE TEST, turn the main power
disconnect switch to the "Off" position or proceed to
the next component start-up procedure.
Units with Direct Drive Indoor Fan Electromechanical Control
Much of the systems performance and reliability is closely
associated with, and dependent upon having the proper
airflow supplied both to the space that is being
conditioned and across the evaporator coil. The indoor fan
speed is changed by adjusting the output voltage from the
MMC/ECM board to the direct drive fan. Before starting the
SERVICE TEST, set the minimum positio n setpoint for the
economizer to 0 percent using the setpoint potentiometer
located on the Economizer Control (ECA), if applicable.
ReliaTel units with Direct Drive Indoor Fan
(7.5 - 10 Ton High Efficiency, 10 Ton
Standard Efficiency)
Much of the systems performance and reliability is closely
associated with, and dependent upon having the proper
airflow supplied both to the space that is being
conditioned and across the evaporator coil. The indoor fan
speed is changed by adjusting the voltage from the RTOM
Indoor Fan Speed output to the direct drive plenum fan. If
installed, before starting the SERVICE TEST disable the
Economizer by disconnecting the 4 pin power connector
located at the base of the Economizer Control (ECA).
Using the Service Test Guide in Table 10, p. 60,
momentarily jump across the T est 1 & Test 2 terminals on
LTB1 . Repeat process until Service Test Mode is at Cool 2
(2-Steps of Cooling Applications Only) or Cool 3 (3-Steps
of Cooling applications). The indoor motor shall be
operating @ 1 00%, to verify turn DA COOL_FAN SPD
potentiometer full cloc kwise, voltage should read ~7.5 Vdc
across harness test terminals. The Unit schematic
illustrates location for measuring the indoor motor speed
voltage.
Table 10. RPM table
Potentiometer
Voltage
1.252174.501061
1.503124.751126
1.753625.001191
2.004275.251253
2.254795.501315
2.505435.751374
2.756056.001432
3.006686.251487
3.257326.501539
3.507976.751588
3.758637.001633
4.009297.251675
4.259957.501700
Note: Factory setting is 7.5V
Motor RPM
Potentiometer
Voltage
Motor RPM
Once the supply fan has started, determine the total
system airflow (CFM)
1. Measure the DC voltage across harness test terminals.
Using the fan rpm table shown above, determine RPM
correlated to measured voltage.
2. If the required CFM is too low, (external static pressure
is high causing motor HP output to be below table value),
a. Relieve supply and/or return duct static.
b. Change indoor fan speed and repeat steps 1 and 2.
•To Increase/Decrease Fan RPM turn DA COOL_FAN
SPD on the RTOM clockwise/counter-clockwise.
3. If the required CFM is too high, (external static p ressure
is low causing motor HP output to be above table value),
change indoor fan speed and repeat steps 1 and 2.
•Stop the SERVICE TEST, turn the main power
disconnect switch to the "Off" position and reconnect
Economizer 4-pin power connector if disconnected for
this procedure.
Proceed to the next component start-up procedure.
44 RT-SVX22J-EN
Page 45
Start-Up
Electro Mechanical Control: Using the Service Test
Guide perform the proper test mode connections.
Once the supply fan has started, determine the total
system airflow (CFM) by (ReliaTel/Electromechanical):
1 . Measure the DC voltage across pins Vt and com on the
MMC board or note the DC voltage shown on the ECM
board display. Using the fan rpm table shown above,
determine RPM correlated to measured voltage.
2. Measure the amperage at the supply fan contactor and
compare it with the full load amp (FLA) rating for the
evaporator motor stamped on the unit nameplate.
a. Calculate the theore tical BHP using (Actual Motor
Amps/Motor Nameplate Amps) X Motor HP
b. Using the fan performance tables in the unit Service
Facts, plot the actual RPM (step 1) and the BHP (step
2a) to obtain the operating CFM.
3. If the required CFM is too low, (external static pressure
is high causing motor HP output to be below table
value),
a. Relieve supply and/or return duct static.
b. Change indoor fan speed and repeat steps 1 and 2.
•For MMC board: T o increase or decrease fan RPM push
and turn knob counter-clockwise or clockwise
respectively. Measure the DC voltage across pins Vt
and com on the MMC. Using the fan rpm table above,
determine RPM correlated to measured voltage.
•For ECM board: To Increase/Decre ase Fan RPM:
a. Push and hold the SET button for 3 sec. Board will
display Motor 1 parameter name: Hi 1.
b. Slow push SET again to display the parameter’s
current value =7.50 volts.
c. Push on + or – button to adjust parameter to desired
value = XXX volts.
d. Push and hold SET button for 3 sec to “save” the
value. After save is comp lete, Hi 1 wi ll show ag ai n.
e. After the voltage Hi 1 is successfully changed, the
The motor will ramp up or down to adjust to the input
signal. Using the fan rpm table above, determine RPM
correlated to displayed voltage.
•If the required CFM is too high, (external static
pressure is low causing motor HP output to be above
table value), change indoor fan speed and repeat steps
1 and 2.
•To stop the SERVICE TEST, turn the main power
disconnect switch to the “Off” position or proceed to
the next component start-up procedure.
Units with Constant CFM Direct Drive
Indoor Fan
Much of the systems performance and reliability is closely
associated with, and dependent upon having the proper
airflow supplied both to the space that is being
conditioned and across the evaporator coil. The indoor fan
provides a constant CFM base on voltage output for the
potentiometer on the RTOM board. Before starting the
SERVICE TEST, set the minimum position setpoint for the
economizer to 0 percent using the setpoint potentiometer
located on the Economizer Control (ECA), if applicable.
ReliaTel Control. Using the Service Test Guide in
Table 9, p. 42, momentarily jump across the Test 1 & Test
2 terminals on LTB1 one time to start the Minimum
V entilation T e st.
Once the supply fan has started, determine the total
system airflow (CFM) by:
1. Measure the DC voltage across pins TP1 and ground
(screw on corner of RTOM board). Lookup desired CFM
using the voltage CFM table shown on the access panel
label or in the unit Service F acts; record corresponding
voltage. Adjust potentiometer until output voltage
across TP1 and ground ac hieves desired CFM setpoint.
2. To increase voltage/CFM, turn potentiometer
clockwise.
3. To de crease volta ge/CFM, turn potentiometer counterclockwise.
Note: With ID fan access panel removed, fan will operate
at lower RPM due to the decrease in pressure. Once
panel is installed, RPM will increase.
The return air smoke detector is designed to sh ut off the
unit if smoke is sensed in the return air stream. Samplin g
the airflow entering the unit at the return air opening
performs this function.
In order for the smoke detector to properly sense smoke in
the return air stream, the air velocity entering the unit must
be between 500 and 4000 feet per minute. Equipment
covered in this manual will develop an airflow velocity that
falls within these limits over the entire airflow range
specified in the evaporator fan performance tables.
RT-SVX22J-EN45
Page 46
Start-Up
There are certain models however, if operated at low
airflow, will not develop an airflow velocity that falls within
the required 500 to 4000 feet per minute range. For these
models, the design airflow shall be greater than or equal
to the minimum CFM specified in the table provided
below. Failure to follow these instructions will prevent the
smoke detector from performing its design function.
Economizer Start-Up
WARNING
Live Electrical Components!
During installation, testing, servicing and
troubleshooting of this produ ct, it ma y be necessary t o
work with live electrical components. Have a qualified
licensed electrician or other individual who has been
properly trained in handling live electrical components
perform these tasks. Failure to follow all electrical
safety precautions when exposed to live electrical
components could result in death or serious injury.
Minimum Position Setting for 17 Plus, 7.5-10
Ton with Multi-Speed, or Single Zone VAV
1. Apply power to the unit
2. Using the Service Test Guide on unit access panel,
momentarily jump across the Test 1 & Test 2 terminals
on LTB1 one time to start indoor fan.
3. Turn the MIN POS - DCV potentiometer on the RTEM
clockwise to open or counter-clockwise to close. The
damper will open to this setting for low speed fan
operation. When adjusting minimum positi on, the
damper may move to the new setting in several small
steps. Wait at least 15 seconds for the damper to settle
at the new position. Range of damper for this setting is
0-100%.
4. Momentarily jump across the Test 1 & Test 2 terminals
on LTB1, to cycle through test modes to Cool 1.
5. Turn the DCV SETPOINT - LL potentiometer on the
RTEM cloc kwise to open or counter -cloc kwise to close.
This will set the minimum damper position at an
intermediate point of fan operation range of damper
for this setting is 0-75%.
6. Momentarily jump across the Test 1 & Test 2 terminals
on LTB1, to cycle through test modes to Cool 2.
7. Turn the MIN POS - DESIGN potentiometer on the
RTEM cloc kwise to open or counter -cloc kwise to close.
This will set the minimum damper position at
maximum fan speed. Range of damper for this setting
is 0-50%.
8. The economizer minimum damper position for all fan
speeds is complete. The RTEM will control minimum
damper position along an imaginary line between the
3 damper minimum positions based on fan speed.
Note: The RTEM will limit intermediate minim um
damper position to ensure proper ventilation based
upon the low fan speed minimum damper position set
in Step 3.
9. Replace the filter access panel. The damper will close
when the blower circuit is de-energized.
WARNING
Live Electrical Components!
During installation, testing, servicing and
troubleshooting of this product, it may be necessary to
work with live electrical components. Have a qualified
licensed electrician or other individual who has been
properly trained in handling live electrical components
perform these tasks. Failure to follow all electrical
safety precautions when exposed to live electrical
components could result in death or serious injury.
ReliaTel Control: Using the Service Test Guide in
Table 9, p. 42, momentarily jump across the Test 1 & Test
2 terminals on LTB1 one time to start the Minimum
V entilation T e st belo w.
Electro Mechanical Control: Using the Service Test
Guide perform the proper test mode connections.
1 . Set the minimum position setpoint for the economizer
to the required percentage of minimum ventilation
using the setpoint potentiometer located on the
Economizer Control (ECA).
The economizer will drive to its minimum position
setpoint, exhaust fans (if applicable) may start at
random, and the supply fan will start when the
SERVICE TEST is initiated.
WARNING
Rotating Components!
During installation, testing, servicing and
troubleshooting of this product it may be necessary to
work wi th live and exposed rotating co mponents. Hav e
a qualified or licensed service individual who has been
properly trained in handling exposed rotating
components, perform these tasks. Failure to follow all
safety precautions could r esult in r otati ng compon ents
cutting and slashing technician which could result in
death or serious injury.
The Exhaust Fan will start anytime the economizer
damper position is equal to or greater than the exhaust
fan setpoint.
2. Verify that the dampers stroked to the minimum
position.
ReliaTel Control. Momentarily jump across the T est 1 &
Test 2 terminals on LTB1 one additional time if
continuing from previous component start-up or until
the desired start-up component Test is started.
Electro Mechanical Control. Using the Service Test
Guide perform the proper test mode connections.
46 RT-SVX22J-EN
Page 47
Start-Up
3. Verify that the dampers stroked to the full open
position.
4. To stop the SERVICE TEST, tur n the main power
disconnect switch to the “Off” position or proceed to
the next component start-up procedure. Remove
electro mechanical test mode connections (if
applicable).
Compressor Star t-Up
WARNING
Live Electrical Components!
During installation, testing, servicing and
troubleshooting of this product, it may be necessary to
work with live electrical components. Have a qualified
licensed electrician or other individual who has been
properly trained in handling live electrical components
perform these tasks. Failure to follow all electrical
safety precautions when exposed to live electrical
components could result in death or serious injury.
1. Attach a set of service gauges onto the suction and
discharge gauge ports for each circuit. Refer to the
refrigerant circuit illustration in the Service Facts.
ReliaTel Control. Momentarily jump across the T est 1 &
Test 2 terminals on LTB1 one additional time if
continuing from previous component start-u p or until
the desired start-up component Test is started.
Electro Mechanical Control. Using the Service Test
Guide perform the proper test mode connections.
Scroll Compressors.
a. Once each compressor has started, verify that the
rotation is correct. If a scroll compressor is rotating
backw ard s, it will no t pum p an d a loud rattling
sound can be observed.
b. If the electrical phasing is correct, before
condemning a compressor, interchange any two
leads (at the compressor Terminal block) to check
the internal phasing. If the compressor runs
backward for an extended period (15 to 30 minutes),
the motor winding can overheat and cause the
motor winding thermostat to open.
2. After the compressor and condenser fan have started
and operated for approximately 30 minutes, observe
the operating pressures. Compare the operating
pressures to the operating pressure curve in the
Service Facts.
3. Check system superheat. Follow the instruction listed
on the superheat charging curve in the S ervice Facts.
Superheat should be within ±5ºF of the superheat chart
value.
4. Repeat steps 1 through 4 for each refrigerant circuit.
5. To stop the SERVICE TEST, turn the main power
disconnect switch to the “Off” position or proceed to
the next component start-up procedure. Remove
electro mechanical test mode connections (if
applicable).
Dehumidification Option
WARNING
Live Electrical Components!
During installation, testing, servicing and
troubleshooting of this product, it may be necessary to
work with live electrical components. Have a qualified
licensed electrician or other individual who has been
properly trained in handling live electrical components
perform these tasks. Failure to follow all electrical
safety precautions when exposed to live electrical
components could result in death or serious injury.
Momentarily jump across the T est 1 and T est 2 terminals of
the LTB1 until the unit enters test mode 7. (See Table 9,
p. 42). Once the unit is in the reheat test mode, verify that
the 3 way valve has shifted to the reheat position and that
the supply temperature rises 10 ºF more than when in
cooling mode stage 2.
Monitor the suction pressure for 15 minutes . The suct ion
pressure should remain within 5 psi of normal cooling
operation. If the unit has a 2 speed outdoor fan and if the
outdoor air temperature is below 70°F, verify that the OD
fan is in low speed.
1. Clamp an amp meter around one of 1st stage heater
power wires at the heater contactor.
ReliaTel Control. Using the Service Test Guide in
Table 9, p. 42, continue the SERVICE TEST start-up
procedure for each compressor circuit.
Momentarily jump across the T est 1 & Test 2 terminals
on L TB one additional time if continuing from previous
component start-up or until the desired start-up
component Test is started.
Electro Mechanical Control. Using the Service Test
Guide perform the proper test mode connections;
2. Verify that the heater stage is operating properly.
3. Clamp an amp meter around one of 2nd stage heater
power wires at the heater contactor (if applicable).
ReliaTel Control. Using the Service Test Guide in
Table 9, p. 42, continue the SERVICE TEST start-up
procedure for each compressor circuit. Momentarily
jump across the Test 1 & Test 2 terminals on LTB one
additional time if continuing from previous
component start-up or until the desired start-up
component Test is started.
RT-SVX22J-EN47
Page 48
Start-Up
Electro Mechanical Control. Using the Service Test
Guide (Table 9, p. 42) perform the proper test mode
connections;
4. Verify that the heater stage is operating properly
5. To stop the SERVICE TEST, tur n the main power
disconnect switch to the “Off” position or proceed to
the next component start-up procedure. Remove
electro mechanical test mode connections (if
applicable).
Final System Setup
After completing all of the pre-start and start-up
procedures outlined in the previous sections (i.e.,
operating the unit in eac h of its Mo des thro ug h al l
available stages of cooling & heating), perform these final
checks before leaving the unit:
•Program the Night Setbac k (NSB) panel ( if applicable)
for proper unoccupied operation. Refer to the
programming instructions for the specific panel.
•Verify that the Remote panel “System” selection
switch, “Fan” selection switch, and “Zone
Temperature” settings for automatic operation are
correct.
•Inspect the unit for misplaced tools, hardware, and
debris.
•Verify that all exte rior panels including the control
panel doors and condenser grilles are secured in place.
•Close the main disconnect switch or circuit protector
switch that provides the supply power to the unit’s
terminal block or the unit mounted disconnect switch.
Make sure all personnel are standing clear of the unit
before proceeding. The system components will star t
when the power is applied.
48 RT-SVX22J-EN
Page 49
Maintenance
Fan Belt Adjustment - Belt Drive
Units
WARNING
Rotating Components!
During installation, testing, servicing and
troubleshooting of this product it may be necessary to
work with live and exposed rotating components. Have
a qualified or licensed service individual who has been
properly trained in handling exposed rotating
components, perform these tasks. Failure t o follow all
safety prec autions could result in rotating components
cutting and slashing te chnician which could result in
death or serious injury.
The fan belts must be inspected periodically to assur e
proper unit operation.
Replacement is necessary if the belts appear frayed or
worn. Units with dual belts require a matc hed set of belts
to ensure equal belt length.
When removing or installing the new belts, do no t stretc h
them over the sheaves. Loosen the belts using the belt
tension adjustment bolts on the motor mounting base.
Once the new belts are installed, using a Browning or
Gates tension gauge (or equivalent) illustrated in
Figure 53, p. 49; adjust the belt tension as follows;
1. To determine the appropriate belt deflection;
a. Measure the center-to-center shaft distance (in
inches) between the fan and motor sheaves.
b. Divide the distance measured in Step 1 a by 64; the
resulting value represents the amount of belt
deflection that corresponds to the proper belt
tension.
2. Set the large O-ring on the belt tension gauge at the
deflection value determined in Step 1b.
3. Set the small O-ring at zero on the force scale of the
gauge plunger.
4. Place the large end of the gauge at the center of the belt
span; then depress the gauge plunger until the large Oring is even with the top of the next belt or even with
a straightedge placed across the fan and motor
sheaves. Refer to Figure 53, p. 49.
5. Remove the belt tension gauge. The small O-ring now
indicates a number other than zero on the plunger’s
force scale. This number represents the force (in
pounds) required to give the needed deflection.
6. Compare the “force” scale reading (Step 5) with the
appropriate “force” value listed in T able 12, p. 49. If the
“force” reading is outside the range, readjust the belt
tension.
Note: Actual belt deflection “force” must not exceed the
maximum “force” value shown in Figure 53, p. 49.
7. Recheck the belt tension at least twice during the first
2 to 3 days of operation. Belt tension may decrease
until the new belts are “run in”.
Figure 53. Belt tension gauge
Table 12. Belt tension measurement and deflection
Deflection Force (Lbs.)
Belts
Cross
Section
A
B
Small
P.D
Range
3.0 - 3.6 34 1/2 3 7/85 1/2 3 1/44
3.8 - 4.8 3 1/2 54 1/26 1/4 3 3/44 3/4
5.0 - 7.0 45 1/2 56 7/8 4 1/45 1/4
3.4 - 4.2 45 1/2 5 3/484 1/25 1/2
4.4 - 5.6 5 1/8 7 1/8 6 1/29 1/8 5 3/47 1/4
5.8 - 8.8 6 3/8 8 3/4 7 3/810 1/8 78 3/4
Super
GripbeltsGripnotch
Min.Max. Min.Max. Min.Max
Steel Cable
Gripbelts
Monthly Maintenance
WARNING
Hazardous Voltage!
Disconnect all electric power, including remote
disconnects before servicing. Follow proper lockout/
tagout procedures to ensure the pow er can not be
inadvertently energized. Failure to disconnect power
before servicing could result in death or serious injury.
Before completing the following chec ks, turn the unit OFF
and lock the main power di scon nect sw itch open.
Filters
Inspect the return air filters. Clean or replace them if
necessary. Refer to the unit Service Facts for filter
information.
RT-SVX22J-EN49
Page 50
Maintenance
Return Air Smoke Detector Maintenance
Airflow through the unit is affected by the amount of dirt
and debris accumulated on the indoor coil and filters. To
insure that airflow through the unit is adequate for proper
sampling by the return air smoke detector, complete
adherence to the maintenance procedures, including
recommended intervals between filter changes, and coil
cleaning is required.
Periodic checks and maintenance procedures must be
performed on the smoke detector to insure that it will
function properly. For detailed instructions concerning
these checks and procedures, refer to the appropriate
section(s) of the smoke detector Installation and
Maintenance Instructions provided with the literature
package for this unit.
Cooling Season
•Check the unit’s drain pans and condensate piping to
ensure that there are no blockages.
•Inspect the evaporator and condenser coils for dirt,
bent fins, etc. If the coils appear dirty, clean them
according to the instructions described in “Coil
Cleaning” later in this section.
•Manually rotate the condenser fan(s) to ensure free
movement and check motor bearings for wear. Verify
that all of the fan mounting hardware is tight.
•Inspect the F/A-R/A damper hinges and pins to ensure
that all moving parts are securely mounted. Keep the
blades clean as necessary.
•Verify that all damper linkages move freely; lubricate
with white grease, if necessary.
•Check supply fan motor bearings; repair or replace the
motor as necessary.
•Check the fan shaft bearings for wear. Replace the
bearings as necessary.
•Check the supply fan belt. If the belt is frayed or worn,
replace it. Refer to the “Fan Belt Adjustment” section
for belt replacement and adjustments.
•Verify that all wire terminal connections are tight.
•Remove any corrosion present on the exterior surfaces
of the unit and repaint these areas.
•Generally inspect the unit for unusual condition s (e.g.,
loose access panels, leaking piping connections, etc.)
•Make sure that all retaining screws are reinstalled in
the unit access panels once these chec ks are complete.
•With the unit running, check and record the: ambient
temperature; compressor suction and discharge
pressures (each circuit); superheat (each circuit);
•Record this data on an “operator’s maintenance log”
like the one shown in Table 13, p. 52. If the operating
pressures indicate a refrigerant shortage, measure the
system superheat. For guidelines, refer to the
“Compressor Start-Up” section.
Important: Do not release refrigerant to the
atmosphere! If adding or removing
refrigerant is required, the service
technician must comply with all federal,
state and local laws.
Heating Season
•Inspect the unit’s air filters. If necessary, clean or
replace them.
•Check supply fan motor bearin gs; repair or replace the
motor as necessary.
•Inspect both the main unit control panel and heat
section control box for loose electrical components
and terminal connections, as well as damaged wire
insulation. Make any necessary repairs.
•Verify that the electric heat system operates properly.
Coil Cleaning
Regular coil maintenance, including annual cleaning,
enhances the unit’s operating efficiency by minimizing:
compressor head pressure and amperage draw;
evaporator water carryover; fan brake horsepower, due to
increase static pressure losses; airflow reduction.
At least once each year , or more often if the unit is located
in a “dirty” environment, clean the evaporator and
condenser coils using the instructions outlined below. Be
sure to follow these instructions as closely as possible to
avoid damaging the coils.
Note: For units equipped with hail guards follow removal
procedure listed below.
Hail Guard Removal
•Unlatch hail guard.
•Pull the top of the hail guard outward unt il the fastener
studs are free of the retaining nuts.
•Lift the hail guard from the lower retaining bracket and
set aside.
To clean refrigerant coils, use a soft brush and a sprayer
(either a garden pump-up type or a high-pressure sprayer).
A high-quality detergent is also required; suggested
brands include “SPREX A.C.”, “OAKITE 161”, “O AKITE 166”
and “COIL OX”. If the detergent selected is strongly alkaline
(ph value exceeds 8.5), add an inhibitor.
50 RT-SVX22J-EN
Page 51
Maintenance
Microchannel (MCHE) Coils
NOTICE:
Coil Damage!
DO NOT use any detergents with microchannel
condenser coils. Use pressurized water or air ONLY,
with pressure no greater than 600psi. Failure to do so
could result in coil damage.
For additional information regarding the proper
microchannel coil cleaning procedure, refer to RTSVB83*-EN.
Due to the soft material and thin wall s of the MC HE coils,
the traditional field maintenance method recommended
for Round Tube Plate Fin (RTPF) coils does not apply to
microchannel coils.
Moreover, c hemical cleaners are a risk factor to MCHE due
to the material of the coil. The manufacturer does not
recommend the use of chemical cleaners to clean
microchannel coils. Using c hemical cleaners could lead to
warranty claims being further evaluated for validity and
failure analysis.
The recommended cleaning method for microcha nn el
condenser coils is pressurized water or air with a nonpinpoint nozzle and an ECU of at least 180 with pressure no
greater than 600 psi. T o minim ize the risk of co il damage,
approach the cleaning of the coil with the pressure washer
aimed perpendicular to the face of the coil.
Note: For more details on Microchannel coil cleaning,
please refer to bulletin RT-SVB83*-EN.
Round Tube Plate Fin (RTPF) Coils
WARNING
Hazardous Chemicals!
Coil cleaning agents can be either acidic or highly
alkaline and can burn severely if contact with skin
occurs. Handle chemical carefully and avoid cont act
with skin. AL W AYS wear P ersonal Pr otective E quipment
(PPE) including goggles or face shield, chemical
resistant gloves, boots, apron or suit as required. For
personal safety refer to the cleaning agent
manufact u rer’s Materials Safety D a t a Shee t an d follow
all recommended safe handling practices. Failure to
follow all safety instructions could result in death or
serious injury.
solution BUT DO NOT EXCEED 150ºF maximum to
improve its cleansing capability.
WARNING
Hazardous Pressures!
Coils contain refrig erant under pr essure. When cleaning
coils, maintain coil cleaning solution temperature under
150°F to avoid excessive pressure in the coil. Failure to
follow these safety precautions could result in coil
bursting, which could result in death or serious injury.
5. Pour the cleaning solution into the sprayer. If a highpressure sprayer is used:
a. do not allow sprayer pressure to exceed 600 psi.
b. the minimum nozzle spray angle is 15 degrees.
c. maintain a minimum clearance of 6" between the
sprayer nozzle and the coil.
d. spray the solution perpendicular (at 90 degrees) to
the coil face.
6. Spray the leaving-airflow side of the coil first; then
spray the opposite side of the coil. Allow the cleaning
solution to stand on the coil for five minutes.
7. Rinse both sides of the coil with cool, clean water.
8. Inspect both sides of the coil; if it still appears to be
dirty, repeat Steps 6 and 7.
9. Reinstall all of the components and panels removed in
Step 1 and any protective covers installed in step 2.
Note: For units equipped with hail guards follow
reinstallation procedure listed below.
Hail Guard Reinstallation
10. T o reinstall the hail guard, locate the bot tom of the hail
guard in the lower bracket and secure it to the upper
unit bracket with the attached fasteners.
Note: Secure hail guard latches.
Figure 54. H ail guard
1 . Remove enough panels from the unit to gain access t o
the coil.
2. Protect all electrical devices such as motors and
controllers from any over spray.
3. Straighten any bent coil fins with a fin comb.
4. Mix the detergent with water according to the
manufacturer’s instructions. If desired, heat the
RT-SVX22J-EN51
11. Restore the unit to its operational status and check
system operation.
Annual Maintenance
Clean and repaint any corroded surface.
Page 52
Maintenance
Final Process
For future reference, you may find it helpful to record the
unit data requested in the blanks provided.
Complete Model Number:
Unit Serial Number:
Wiring Diagram Numbers (from
unit control panel):
Connections:
Schematics:
Table 13. Sample maintenance log
Refrigerant Circuit #1 Refrigerant Circuit #2
Date
Current
Ambient
Temp. F/C
Compr.
Oil Level
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
Suct.
Press.
Psig/
kPa
Disch.
Press.
Psig/
kPa
Liquid
Press.
Psig/
kPa
Super
-heat
F/C
Subcool.
F/C
Compr.
Oil
Level
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
Suct.
Press.
Psig/kPa
Disch.
Press.
Psig/
kPa
Liquid
Press.
Psig/
kPa
Superheat
F/C
Subcool.
F/C
Note: Check and record the data requested above each
month during the cooling season with the unit
running.
52 RT-SVX22J-EN
Page 53
Troubleshooting
ReliaTel™ Control
The RTRM has the ability to provide the service personnel
with some unit diagnostics and system status information.
Before turning the main power disconnect switch “Off”,
follow the steps below to check the ReliaTel Refrigeration
Module (RTRM). All diagnostics & system status
information stored in the RTRM will be lost when the main
power is turned “Off”.
WARNING
Live Electrical Components!
During installation, testing, servicing and
troubleshooting of this product, it may be necessary to
work with live electrical components. Have a qualified
licensed electrician or other individual who has been
properly trained in handling live electrical components
perform these tasks. Failure to follow all electrical
safety precautions when exposed to live electrical
components could result in death or serious injury.
To prevent injury or death from electrocution, it is the
responsibility of the technician to recogniz e this hazard
and use extreme care when performing service
procedures with the electrical power energized.
1. Verify that the Liteport LED on the RTRM is burning
continuously. If the LED is lit, go to Step 3.
2. If the LED is not lit, verify that 24 VAC is presence
between J1-1 and J1-2. If 24 V AC is present, proceed to
Step 4. If 24 VAC is not present, check the unit main
power supply, check transformer (TNS1). Proceed to
Step 3 if necessary.
3. Utilizing “Method 1” or “Method 2” in the “System
Status Diagnostic” section, check the following:
• System status
• Heating status
• Cooling status
If a System failure is indicated, proceed to Step 4. If no
failures are indicated, proceed to Step 5.
4. If a System failure is indicated, recheck Step 1 and Step
2. If the LED is not lit in Step 1, and 24 VAC is present
in Step 2, the RTRM has failed. Replace the RTRM.
5. If no failures are indicated, use one of the TEST mode
procedures described in the “Unit Start-Up” section to
start the unit. This procedure will allow you to c heck all
of the RTRM outputs, and all of the external controls
(relays, contactors, etc.) that the RTRM outputs
energize, for each respective mode. Proceed to Step 6.
6. Step the system through all of the available modes,
and verify operation of all outputs, controls, and
modes. If a problem in operation is noted in any mode,
you may leave the system in that mode for up to one
hour while troubleshooting. Refer to the sequence of
operations for each mode, to as sist in verifying proper
operation. Make the necessary repairs and proceed to
Step 7 and Step 8.
7. If no abnormal operating conditions appear in the test
mode, exit the test mode by turning the power “Off ” at
the main power disconnect switch.
8. Refer to the individual component test procedures if
other microelectronic components are suspect.
System Status Checkout
Procedure
“System Status” is ch ec ked by using one of the following
two methods:
Method 1
If the Zone Sensor Module (ZSM) is equipped with a
remote panel with LED status indication, you can check the
unit within the space. If the ZSM does not have LED’s, use
Method 2. BAYSENS110*, BAYSENS109*, BAYSENS1 19*,
BAYSENS023A all have the remote panel indication
feature. The LED descriptions are listed below.
LED 1 (System)
“On” during normal operation.
“Off” if a system failure occurs or the LED fails.
“Flashing” indicates test mode.
LED 2 (Heat)
“On” when the heat cycle is operating.
“Off” when the heat cycle terminates or the LED fails.
“Flashing” indicates a heating failure.
LED 3 (Cool)
“On” when the cooling cycle is operating.
“Off” when the cooling cycle terminates or the LED fails.
“Flashing” indicates a cooling failure.
LED 4 (Service)
“On” indicates a clogged filter.
“Off” during normal operation.
“Flashing” indicates an evaporator fan or condensate
overflow failure.
Below is the complete listing of failure indication causes.
System failure
Check the voltage between terminals 6 and 9 on J6, it
should read approximately 32 VDC. If no voltage is
present, a System failure has occurred. Refer to Step 4 in
the previous section for the recommended
troubleshooting procedure.
RT-SVX22J-EN53
Page 54
Troubleshooting
Cooling Failure
•Cooling and heating set point (slide pot) on the zone
sensor has failed. Refer to the “Zone S e nsor Te st
Procedure” section.
•Zone temperature thermistor ZTEMP on ZTS failed.
Refer to the “Zone Sensor Test Procedure” section.
•CC1 or CC2 24 VAC control circuit has opened, check
CC1 & CC2 coils, and any of the controls below that
apply to the unit (HPC1, HPC2).
•LPC1 has opened during the 3 minute minimum “on
time” during 4 consecutive compressor starts, check
LPC1 or LPC2 by testing voltage between the J1-1 & J32 terminals on the RTRM and ground. If 24 VAC is
present, the LPC’s has not tripped. If no voltage is
present, LPC’s has tripped.
Service Failure
•If the supply fan proving switc h has closed, the unit will
not operate (when connected to RTOM), c hec k the fan
motor, belts, and proving switch.
•Clogged filter switch has closed, check the filters.
•If the condensate overflow switch is closed, the unit
will not operate. Make sure the float switch is not in a
tripped condition, and check for an "open" between
wires connecting to RTOM J6-1, J6-2 (ReliaTel
controls).
Simultaneous Heat and Cool Failure
•Emergency Stop is activated
Method 2
The second method for determining system statu s is done
by chec king voltage readings at the RTRM (J6). The system
indication descriptions and the approximate voltages are
listed below.
System Failure
Measure the voltage between terminals J6-9 & J6-6.
Normal Operation = approximately 32 VDC
System Failure = less than 1 VDC, approximately 0.75 VDC
Test Mode = voltage alternates between 32 VDC & 0.75
VDC
Heat Failure
Measure the voltage between terminals J6-7 & J6-6.
Heat Operating = approximately 32 VDC
Heat Off = less than 1 VDC, approximately 0.75 VDC
Heating Failure = v olta g e al ternates between 32 VDC &
0.75 VDC
Cool Failure
Measure the voltage between terminals J6-8 & J6-6.
Cool Operating = approximately 32 VDC
Cool Off = less than 1 VDC, approximately 0.75 VDC
Cooling Failure = voltage alternates between 32 VDC &
0.75 VDC
Service Failure
Measure the voltage between terminals J6-10 & J6-6.
Clogged Filter = Approximately 32 VDC.
Normal = Less than 1 VDC, approximately 0.75 VDC Fan
Failure = voltage alternates between 32 VDC & 0.75 VDC.
To use LED’s for quick status information at the unit,
purchase a BAYSENS110* ZSM and connect wires with
alligator clamps to terminals 6 through 1 0. Connected each
respective terminal wire (6 through 10) from the Zone
Sensor to the unit J6 terminals 6 through 10.
Note: If the system is equipped with a programmable
zone sensor, (BAYSENS119*, or BAYSENS023A),
the LED indicators will not function while the
BAYSENS110* is connected.
Resetting Cooling and Ignition Lockouts
Cooling Failures and Heating Lockouts are reset in an
identical manner. Method 1 explains reset ting the system
from the space; Method 2 explains resetting the system at
the unit.
Note: Before resetting Coolin g Failures and Ignition
Lockouts check the Failure Status Diagnostics by
the methods previously explained. Diagnostics will
be lost when the power to the unit is disconnected.
Method 1
To reset the system from the space, turn the “Mode”
selection switch at the zone sensor to the “Off” position.
After approximately 30 seconds, turn the “Mode”
selection switch to the desired mode, i.e. Heat, Cool or
Auto.
Method 2
To reset the system at the unit, cycle the unit power by
turning the disconnect switch “Off” and then “On”.
Lockouts can be cleared through the building
management system. Refer to t he b uil di ng m an age ment
system instructions for more information.
Zone Temperature Sensor (ZTS)
Service Indicator
The ZSM SERVICE LED is a generic indicator, that will
signal the closing of a Normally Open switch at an y time,
providing the Indoor Motor (IDM) is operating. This
indicator is usually used to indicate a clogged filter, or an
air side fan failure.
54 RT-SVX22J-EN
Page 55
Troubleshooting
The RTRM will ignore the closing of this Normally Open
switch for 2 (±1) minutes. This helps prevent nuisance
SERVICE LED indications. The exception is the LED will
flash 40 seconds after the fan is turned “On” if the Fan
Proving Switch is not made.
Clogged Filter Switch
This LED will remain lit the entire time that the Normally
Open switch is closed. Th e LE D will be turned off
immediately after resetting the switch (to the Normally
Open position), or any time that the IDM is turned “Off”.
If the switch remains closed, and the IDM is turned “On”,
the SERVICE LED will be turned “ On” again after the 2 (±1)
minute ignore delay.
This LED being turned “On”, will have no other affect on
unit operation. It is an indicator only.
Fan Failure Switch
When the “Fan Failure” switch is wired to the RTOM, the
LED will remain flashing the entire time the fan proving
switch is clos ed, indicating a fan failure, and it will shut the
unit operations down.
Condensate Overflow Switch
When the “Condensate Overflow Switch" is closed, a drain
pan overflow condition is indicated and it will shut unit
operations down.
The resistance of these potentiometers are measured
between the following ZSM terminals. Refer to the chart
above for approxim ate re sistanc es at the given setpoints.
Cool SP = Terminals 2 and 3
Range = 100 to 900 Ohms approximate
Heat SP = Terminals 2 and 5
Range = 100 to 900 Ohms approximate
Nominal ZTEMP
Resistance
Test 3 - System Mode and Fan Selection
The combined resistance of the Mode selection switch and
the Fan selection switch can be measured between
terminals 2 and 4 on the Zone Sensor. The possible switch
combinations are listed below with their corresponding
resistance values.
Test 4 - LED Indicator Test, (SYS ON, HEAT,
COOL & SERVICE)
Method 1
Zone Temperature Sensor (ZTS)
Test
Note: These procedures are not for programmable or
digital models and are conducted with the Zone
Sensor Module electrically removed from the
system.
Test 1 - Zone Temperature Thermistor
(ZTEMP)
This component is tested by measuring the resistance
between terminals 1 and 2 on the Zone Temperature
Sensor . Below are some typical indoor temperatures, and
corresponding resistive values.
Test 2 - Cooling Set Point (CSP) and
Heating Set Point (HSP)
T esting the LED using a meter with diode test function. T est
both forward and reverse bias. Forward bias should
measure a voltage drop of 1.5 to 2.5 volts, depending on
your meter . Reverse bias will show an Over L oad, or open
circuit indication if LED is functional.
Method 2
Testing the LED with an analog Ohmmeter. Connect
Ohmmeter across LED in one direction, then reverse the
leads for the opposite direction. The LED should have at
least 100 times more resistance in reverse direction, as
compared with the forward direction. If high resistance in
both directions, LED is open. If low in both directions, LE D
is shorted.
Method 3
To test LED’ s with ZSM connected to unit, test v oltages at
LED terminals on ZSM. A measurement of 32 VDC, across
an unlit LED, means the LED has failed.
Relative Humidity Sensor Test
This component is measured by measuring the mA o utput
signal on the Relative Humidity Sensor. V erify accuracy of
the sensor annually. If the output reading is 0 mA, first
verify that power is applied to the sensor. A reading of 4
mA corresponds to 0% RH and 20 mA corresponds to 100%
RH.
RT-SVX22J-EN55
Page 56
Troubleshooting
% RHmA
308.8
4010.4
5012.0
6013.6
7015.2
8016.8
Note: Measurements should be made from LED common
(ZSM terminal 6 to respective LED terminal). Refer
to the Zone Sensor Module (ZSM) Terminal
Identification table at the beginning of this section.
Progra mmable & Digital Zone
Sensor Test
Testing serial communication voltage
1 . Verify 24 V A C is present between terminals J6-14 & J6-
11.
2. Disconnect wires from J6-11 and J6-12. Measure the
voltage between J6-11 and J6-12, should be about 32
VDC.
3. Reconnect wires to terminals J6-1 1 and J6-12. Measure
voltage again between J6-1 1 and J6-12, voltage should
flash high and low every 0.5 seconds. The voltage on
the low end will measure about 19 VDC, while the
voltage on the high end will measure from
approximately 24 to 38 VDC.
4. Verify all modes of operation, by running the unit
through all of the steps in Table 9, p. 42.
5. After verifying proper unit operation, exit the test
mode. Turn the fan on continuously at the ZSM, by
pressing the button with the fan symbol. If the fan
comes on and runs continuously, the ZSM is good. If
you are not able to turn the fan on, the ZSM is
defective.
If the RTCI loses input from the building manageme nt
system, the RTRM will control in the default mode after
approximately 15 minutes. If the RTRM loses the Heating
and Cooling setpoint input, the RTRM will control in the
default mode instantaneously. The temperature sensing
thermistor in the Zone Sensor Module is the only
component required for the “Default Mode” to operate.
Unit Operation without a Zone Sensor
This procedure is for temporary operation only. The
economizer and condenser fan cycling functions are
disabled.
WARNING
Hazardous Voltage!
Disconnect all electric power, including remote
disconnects before servicing. Follow proper lockout/
tagout procedures to ensure the pow er can not be
inadvertently energized. Failure to disconnect power
before servicing could result in death or serious injury.
1. Open and Lock the unit disconnect switch.
2. Remove the Outside Air Sensor (OAS) from the
condenser section of unit.
3. Use two (2) wire nuts, to individually cap the wires.
4. Locate the RTRM (J6). Connect two (2) wires to
terminals J6-1 and 2.
5. Connect the sensor (OAS) using two wire nuts to the
two (2) field supplied wires that were connected to
terminals 1 and 2 on J6.
Unit Economizer Control (ECA)
Troubleshooting
ReliaTel Control
Verify Economizer Status by Economizer Actuator (ECA)
LED indicator:
•OFF: No Power or Failure
•ON: Normal, OK to Economize
•Slow Flash: Normal, Not OK to Economize
•Fast Flash - 1/2 Second On / 2 Se con ds Off:
• Error Code: Communications Failure
•Pulse Flash: 2 Seconds On / 1/2 Second Off:
• Error Code:
• 1 Flash: Actuator Fault
• 2 Flashes: CO
• 3 Flashes: RA Humidity Sensor
• 4 Flashes: RA Temp Sensor
• 5 Flashes: OA Quality Sensor
• 6 Flashes: OA Humidity Sensor
• 7 Flashes: OA Temp Sensor
• 8 Flashes: MA Temp Sensor
• 9 Flashes: RAM Fault
• 10 Flashes: ROM Fault
• 11 Flashes: EEPROM Fault
Sensor
2
56 RT-SVX22J-EN
Page 57
Troubleshooting
Electro Mechanical Control
WARNING
Live Electrical Components!
During installation, testing, servicing and
troubleshooting of this prod uct, it may be necessary to
work with live electrical components. Have a qualified
licensed electrician or other individual who has been
properly trained in handling live electrical components
perform these tasks. Failure to follow all electrical
safety precautions when exposed to live electrical
components could result in death or serious injury.
To prevent injury or death from electrocution, it is the
responsibility of the technician to recogniz e this hazard
and use extreme care when performing service
procedures with the electrical power energized.
Cooling Failure
1. Cooling and heating set point (slide pot) on the
thermostat has failed.
2. CC1 or CC2 24 VAC control circuit has opened, check
CC1 & CC2 coils, and any of the controls below that
apply to the unit (HPC1, HPC2, LPC1, LPC2, Frostat™).
Resetting Cooling and Heating Lockouts
Cooling Failures and Heating Lockouts are reset in an
identical manner . Method 1 explains resettin g the system
from the space; Method 2 explains resetting the system at
the unit.
Method 1
To reset the system from the space, turn the “Mode”
selection switch at the thermostat to the “Off” position.
After approximately 30 seconds, turn the “Mode”
selection switch to the desired mode, i.e. Heat, Cool or
Auto.
Method 2
To reset the system at the unit, cycle the unit power by
turning the disconnect switch “Off” and then “On”.
Unit Economizer Control (ECA)
Test Procedures
1 . Using the “T est Mode” described in the “System Star t-
Up” section, put the unit into the economizer mode
and verify that the economizer actuator (ECA) drives
fully open (approximately 90 seconds).
2. If the ECA is not driving the dampers, verify that 24 VAC
is between the ECA terminals TR and TR1 is present. If
24 volts is not present, a wiring or terminal problem
exists from the control transformer. Make any
necessary repairs, see wiring diagrams to
troubleshoot.
3. If 24 VAC is present, adjust the minimum position
potentiometer fully clockwise. If the actuator does not
drive, the economizer actuator is bad. Replace the ECA.
Test 2
Testing the ECA resistors and sensors
1. Testing the Mixed Air Sensor (MAS). Disconnect the
wires connected to T and T1 on the ECA, and;
a. Measure the resistance of the sensor between the
wires 180B and 181B.
b. Measure the temperature at the MAS location.
Using the Temperature versus Resistance chart,
verify the accuracy of the MAS.
Replace the sensor if it is out of range.
2. Testing the Outdoor Air Switch. If the temperature is
above 60 degrees, it will need to be chilled. Measure
the resistance of the sensor on the ECA SO and +.
The resistance should be approximately 390 Ohms.
Replace the Switch if it is open.
Replace the ECA if it is out of range.
3. Testing the R1 R e sistance.
Measure the resistance of the sensor on the ECA SR
and +.
The resistance should be approximately 420 Ohms.
Replace the ECA if it is out of range.
4. Testing the R2 R e sistance.
Measure the resistance of the sensor on the ECA P and
P1.
The resistance should be approximately 130 Ohms.
Replace the ECA if it is out of range.
Electro Mechanical Control
This series of tests will allow you to diagnose, and
determine where, and if a problem exists in the system
economizer operation. Test 1 determines if the problem is
in the Unit, or if it is in the ECA. Test 2 tests sensor inputs.
T est 3 tests the resist ors and sensors. Conduct the tests in
numerical order until problem is found.
Test 1
V erifying that the economizer actuator (ECA) is functional:
RT-SVX22J-EN57
Troubleshooting procedures for
Direct Drive Plenum Fan
Prior to troubleshooting, verify all wiring and wiring
connections. The motor has internal protections that will
shut down the motor before damage occurs. A power
cycle is required to reset some of the internal protections.
Before proceeding, power down unit for 1 minute and then
power on.
Page 58
Troubleshooting
Please follow steps sequentially unless directed differently
in solution.
Table 15. Troubleshooting for direct drive plenum fan
StepSymptom or TestProbable Cause and Solution
If obstruction is present, remove
Obstruction blocking
1
operation of evaporator
fan.
Check line to line voltage
2
at pin 1, 2, and 3 of PPFIDFP.
Verify continuity across
3
fuse FU31, FU32, and
FU33.
Measure DC voltage
across pin Vt and com on
4
MMC or note voltage on
ECM display.
Check for 24VAC across
pins A and B on F relay.
5
For units with no F, go to
step 7.
Check for 10VDC across
6
pin 9 on F relay an pin 8
of PPM-IDFC.
Measure DC voltage
across pin Vt and com on
7
MMC or note voltage on
ECM display.
Verify VDC is same
across Vt and com on
MMC (or ECM display)
8
and pin 1 and pin 8 on
PPM-IDFC.
Verify correct wiring
9
connections at KL3 in the
motor.
power from unit and remove
obstruction. Check fan wheel for
damage. Remove wheel/motor
assembly if damaged.
Voltage should be same as line to line
voltage input to unit. If voltage is
sam e go to s tep 4. If n ot, go t o st ep 3 .
Replace fuse if continuity is not
present.
Voltage should be greater than 1.0
VDC. If voltage is greater the 1.0, go
to step 8. If not, turn knob on MMC
counter-clock wise 1 turn and check
voltage again. For units with ECM
board increase the output voltage by
3.0 VDC and check voltage again. If
no change in voltage, go to step 5
If voltage is not present, verify
thermostat wiring. Go to step 4. If
voltage is present, go to step 6.
If voltage is not present, check wiring
to F relay. Correct wiring if needed.
Go to step 4. If wiring is correct,
replace relay.
Voltage should be greater than 1.0
VDC. If voltage not present, replace
MMC / ECM board.
If voltage is not same, check for
correct wiring. If voltage is the same
go to step 9.
If wiring is correct, replace motor.
58 RT-SVX22J-EN
Page 59
Unit Wiring Diagrams Numbers
Note: Wiring diagrams can be accessed using e-Library
by entering the diagram number in the literature
order number search field or by contacting
technical support.
TCY, TCX, TCC, TCD, TCH, TCM,TCP, TSC
and THC (Parts Only) Models Less Than 20
Tons for Residential Use*
This limited war ranty is extended by Trane to the original
purchaser and to any succeeding owner of the real
property to which the Combination Electric/ Electric Air
Conditioner is originally affixed, and applies to produ cts
purchased and retained for use within the U.S.A. and
Canada.
If any part of your Combination Electric/ Electric Air
Conditioner fails because of a manufacturing defect within
five years from the date of the original purchase,
Warrantor will furnish without charge the required
replacement part. Any local transportation, related service
labor, diagnosis calls, air filters, refrigerant and related
items are not included.
If the sealed motor-compressor fails because of a
manufacturing defect within five years from the date of
original purchase, Warrantor will furnish without charge
the required replacement compressor. Any local
transportation, related service labor, diagnosis calls,
refrigerant and related items are not included.
If the steel heat exchanger fails because of a
manufacturing defect within the sixth through tenth year
from the date of original purchase, War rantor will furnish
without charge a replacement heat exchanger. Any local
transportation, related service labor and diagnosis calls
are not included.
In addition, if the optional, factory installed, stainless steel
heat exchanger fails because of a manufacturing defect
within ten years from the date of start-up, Warrantor will
furnish without charge a replacement heat exc hanger. Any
local transportation, related service labor and diagnosis
calls are not included.
This limited warranty does not cover failure of your
combination Electric/ Electric air conditioner if it is
damaged while in your possession, failure at tributable or
caused by unreasonable use of the combination Electric/
Electric air conditioner and/or failure to properly maintain
the combination Electric/ Electric air conditioner as set
forth in the Use and Care manual.
This limited warranty applies to product installed on or
after 10/1/2001 where product is manufactured after 1/1/
2000. This limited warranty is not retroactive to any
installations prior to 10/1/2001 or on product produced
prior to 2000.
THE LIMITED WARRANTY AND LIABILITY SET FORTH
HEREIN ARE IN LIEU OF ALL OTHER WARRANTIES AND
LIABILITIES, WHETHER IN CONTRACT OR IN
NEGLIGENCE, EXPRESS OR IMPLIED, IN LAW OR IN FACT,
INCLUDING IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR PARTICULAR
USE, AND IN NO EVENT SHALL WARRANT OR BE LIABLE
FOR ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES.
Some states do not allow limitations on how long an
implied limited warranty lasts or do not allow the
exclusion or limitation of incidental or consequential
damages, so the above limitation or exclusion may not
apply to you. This limited war ranty gives you specific legal
rights, and you may also have other rights whic h vary from
state to state.
Parts will be pro vided by our factory organizati on through
an authorized service organization in your area listed in the
yellow pages. If you wish further help or information
concerning this limited warranty, contact:
Trane
2701 Wilma Rudolph Blvd.
Clarksville, TN 37040-1008
Attention: Manager, Product Service
GW-618-4001
* This limited warranty is for residential usage of this
equipment and not applicable when this equipment is
used for a commercial application. A commercial use is
any application where the end purchaser uses the product
for other than personal, family or hous ehold purposes.
RT-SVX22J-EN61
Page 62
Limited Warranty
Electric Air Conditioner
TCY, TCX, TCC, TCD, TCH, TCK, TCM, TCP,
TSC and THC (Parts Only) Models Less
Than 20 Tons for Commercial Use*
This warranty is extended by Trane to the original
purchaser and to any succeeding owner of the real
property to which the Combination Electric/ Electric Air
Conditioner is originally affixed, and applies to produ cts
purchased and retained for use within the U.S.A. and
Canada. There is no warranty against corrosion, erosion or
deterioration.
If any part of your Combination Electric/ Electric Air
Conditioner fails because of a manufacturing defect within
one year from the date of the original purchase, W arrantor
will furnish without charge the required replacement par t.
In addition, if the sealed motor-compressor fails because
of a manufacturing defect within the second throug h fifth
year from the date of original purchase, Warrantor will
furnish without charge the required replacement
compressor.
If the steel heat exchanger fails because of a
manufacturing defect within the second through fifth year
from the date of original purchase, War rantor will furnish
without charge a replacement heat exchanger.
In addition, if the optional, factory installed, stainless steel
heat exchanger fails because of a manufacturing defect
within ten years from the date of start-up, Warrantor will
furnish without charge a replacement heat exc hanger. Any
local transportation, related service labor and diagnosis
calls are not included.
War rantor’ s obligations and liabilities under this war ranty
are limited to furnishing F.O.B. Warrantor factory or
warehouse at Warrantor designated shipping point,
freight allowed to Buyer’s city, replacement parts for
Warrantor’s products covered under this warranty.
War rantor shall not be obligated to pay for the cost of lost
refrigerant. No liability shall attach to Warrantor until
products have been paid for and then liability shall be
limited solely to the purchase price of the equipment
under warranty shown to be defective.
THE WARRAN TY AND LIABILITY SET FOR TH HEREIN ARE
IN LIEU OF ALL OTHER WARRANTIES AND LIABILITIES,
WHETHER IN CONTRACT OR IN NE G LIGENCE, EXPRESS
OR IMPLIED, IN LAW OR IN FACT, INCLUDING IMPLIED
WARRANTIES OF MERCHANT ABILITY AND FITNESS FOR
PARTICULAR USE, AND IN NO EVENT SHALL
WARRANTOR BE LIABLE FOR ANY INCIDENTAL OR
CONSEQUENTIAL DAMAGES.
Some states do not allow limitations on how long an
implied warranty lasts or do not allow the exclusion or
limitation of incidental or consequential damages, so the
above limitation or exclusion may not apply to you. This
warranty gives you specific legal rights, and you may also
have other rights which vary from state to state.
Trane
2701 Wilma Rudolph Blvd.
Clarksville, TN 37040-1008
Attention: Manager, Product Service
GW-606-4800
* This warranty is for commercial usage of said equipment
and not applicable when the equipment is used for a
residential application. Commercial use is any application
where the end purchaser uses the product for other than
personal, family or household purposes.
62 RT-SVX22J-EN
Page 63
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The manufacturer optimizes the performance of homes and buildings around the world . A business of Ingersoll
Rand, the leader in creating and sustaining safe, comfortable and energy efficient environments,the manufacturer
offers a broad portfolio of advanced controls and HVAC systems, comprehensive building services, and parts. For
more information, visit www.IRCO.com.
The manufacturer has a policy of continuous product and product data improvement and reserves the right to change design and specifications without notice.