Trane OA1D OA2D OA3D (Indirect Gas-Fired/Electric Heat) Maintenance Manual
52
OAU-SVX01E-EN
Alarms and Troubleshooting
Microprocessor Control
The Main Unit Display and RTRM have the ability to
provide the service personnel with some unit diagnostics
and system status information.
provide the service personnel with some unit diagnostics
and system status information.
1.
2. If the LED is not lit, verify that 24 Vac is presence
between J1-1 and J1-2. If 24 Vac is present, proceed to
. If 24 Vac is not present, check the unit main
power supply, check transformer (TNS1). Proceed to
if necessary.
3. Utilizing “Method 1” in the RTRM “System Status
Checkout Procedure”, check the following:
•
System status
•
Cooling status
failures are indicated, proceed to
4. If a System failure is indicated, recheck
and
. If the LED is not lit in
, and 24 Vac is present in
, the RTRM has failed. Replace the RTRM.
5. If no failures are indicated, use one of the override
options to start the unit. Following the Override
procedure will allow you to check all of the operating
modes, and all of the external controls (relays,
contactors, etc.) for each respective mode.
procedure will allow you to check all of the operating
modes, and all of the external controls (relays,
contactors, etc.) for each respective mode.
6. Refer to the sequence of operations for each mode, to
assist in verifying proper operation. Make the
necessary repairs and proceed to
necessary repairs and proceed to
.
7.
If no abnormal operating conditions appear in the
Override mode, release the override and turn the
power “Off” at the main power disconnect switch.
Override mode, release the override and turn the
power “Off” at the main power disconnect switch.
System Alarms
The Main Unit Display has built in alarms to help the
operator troubleshoot system failures. This section will
describe these alarms and provide a guide to
troubleshooting the all unit operating modes.
operator troubleshoot system failures. This section will
describe these alarms and provide a guide to
troubleshooting the all unit operating modes.
Comprehensive system alarms and diagnostics are
accessed through the Alarms icon at the unit display
discussed later in the section, or through Tracer TU
programming on connected computer. Sensor failures
may be viewed through the Alarms icon.
accessed through the Alarms icon at the unit display
discussed later in the section, or through Tracer TU
programming on connected computer. Sensor failures
may be viewed through the Alarms icon.
If an alarm is present, the main indicator light on the
UC600 will blink red. If the optional unit display is installed,
the Alarm icon on the display will register ALARM,
illuminate red and flash.
UC600 will blink red. If the optional unit display is installed,
the Alarm icon on the display will register ALARM,
illuminate red and flash.
Important:
The space temperature sensor (SPTC) and
space relative humidity sensor (SPHC) will
read failed if they are not connected; they
will Alarm as “In Fault.”
space relative humidity sensor (SPHC) will
read failed if they are not connected; they
will Alarm as “In Fault.”
Sensor Failure Alarm Display
Press the Alarm button on the Home display of the Unit
Display to display system sensor status as described in
Display to display system sensor status as described in
.
WARNING
Hazardous Service Procedures!
The maintenance and troubleshooting procedures
recommended in this section of the manual could result
in exposure to electrical, mechanical or other potential
safety hazards. Always refer to the safety warnings
provided throughout this manual concerning these
procedures. When possible, disconnect all electrical
power including remote disconnects before servicing.
Follow proper lockout/tagout procedures to ensure the
power can not be inadvertently energized. When
necessary to work with live electrical components, have
a qualified licensed electrician or other individual who
has been trained in handling live electrical components
perform these tasks. Failure to follow all of the safety
warnings provided could result in death or serious
injury.
recommended in this section of the manual could result
in exposure to electrical, mechanical or other potential
safety hazards. Always refer to the safety warnings
provided throughout this manual concerning these
procedures. When possible, disconnect all electrical
power including remote disconnects before servicing.
Follow proper lockout/tagout procedures to ensure the
power can not be inadvertently energized. When
necessary to work with live electrical components, have
a qualified licensed electrician or other individual who
has been trained in handling live electrical components
perform these tasks. Failure to follow all of the safety
warnings provided could result in death or serious
injury.
Table 17.
TOAU UC600 alarms
Point Diagnostic
Possible Cause
1
Indoor Fan
Failure
VFD not operating
Outdoor and/or Return Air Dampers not
Operating Properly
Operating Properly
Indoor Fan Motor Failure
Indoor Fan Failure Switch IFFS (pressure)
Failure
Failure
IFFS Tubing damaged or not properly
connected
connected
Refer to startup procedure
3
OAD Proving
Switch
Switch
No voltage at actuator
Failed OAD power transformer
No continuity thru end switch (check at UC)
Note: If unit optional RA damper is
installed, send switch on OAD is always
proven
installed, send switch on OAD is always
proven
6
Discharge Air
Temp Source
Failure
Temp Source
Failure
BAS communication down
Failed sensor or improper sensor
installation
installation
8
Fire Shutdown
BAS ONLY
10
Low Temp
Lockout
Lockout
Heat Overridden OFF
Compressor(s) Overridden ON
Setpoint Failures Incorrect
DAT sensor malfunction
Reference
for heat failure
issues