T073 — Outside Air Thermistor Failure; T074 — Space Temperature Thermistor Failure; T082 — Space Temperature Offset Sensor Failure; T094 — Discharge Gas Thermistor Failure - Carrier 38APS025 Manual

that is shipped with the compressor, but not installed.
The 115-volt module must be removed and replaced with
the 24-volt module shipped with the compressor. Failure
to do so will not allow the M1-M2 contacts to close, re-
sulting in this alarm.
A060 — Supply Air Thermistor Failure
A060 — Supply Air Temperature Update Not Received
A061 — Return Air Thermistor Failure
A061 — Return Air Temperature Update Not Received
Criteria for Trip: Two alarm criteria are used:
• The sensor is required for the Control Type (Configura-
tion OPT2 C.TYP=1, 3, 5, or 9) and the sensor read-
ing is outside the range of –40 to 245 F (–40 to 118 C). If
this condition is true, the thermistor failure alarm will be
generated.
• If the sensor is required for the Control Type (C.TYP=1,
3, 5, or 9) and the sensor is being written to by CCN or a
third-party control, the sensor must be updated every 3
minutes. If it is not updated, then the Update Not
Received alarm will be generated.
Action To Be Taken: The unit will be shut down.
Reset Method: Automatic, once the condition is resolved
Possible Causes: If this condition is encountered, check the
following items:
• Check for a faulty thermistor.
• Check for a wiring error.
• If temperatures are being transmitted, check transmission
timing and communication wiring.
T068 — Circuit A Compressor Return Gas Temperature
Thermistor Failure
T069 — Circuit B Compressor Return Gas Temperature
Thermistor Failure
Criteria for Trip: This alert occurs when the compressor return
gas temperature thermistor is outside the range of –40 to
245 F (–40 to 118 C).
Action To Be Taken: Circuit is shut down.
Reset Method: Automatic, once the condition resolves
Possible Causes: If this condition is encountered, check the
following items:
• Check for a faulty thermistor.
• Check for a wiring error.
T073 — Outside Air Thermistor Failure
Criteria for Trip: This alert occurs when the outdoor air tem-
perature thermistor is outside the range of –40 to 245 F (–40 to
118 C).
Action to be taken: If the unit is set for outdoor air temperature
reset, reset will be disabled and the unit will run under normal
set point control.
If the unit is configured to use outdoor ambient lockout, the
unit will be shut down or not allowed to start. If the unit is re-
quired to be operating, disable Low Ambient Lockout, Set
Points COOL OAT.L= 20 F (–28.9 C).
Reset Method: Automatic, once the condition resolves.
Possible Causes: If this condition is encountered, check the
following items:
• Check for a faulty thermistor.
• Check for a wiring error.
T074 — Space Temperature Thermistor Failure
Criteria for Trip: This alert occurs when the Space Tempera-
ture Thermistor is outside the range of –40 to 245 F (–40 to
118 C).
Action To Be Taken: If the sensor is being used as the control
input to determine capacity
C.TYP=5 (SPT Multi), the control's response depends on the
failure mode. If the sensor fails open, the unit will be OFF
Configuration OPT2
with the Control Mode, Run Status VIEW STAT=9 (SPT
Satisfied) and Space Temp Control Mode, Run Status
VIEW SPT.M=0 (Cool Off). If the sensor fails closed or
shorted, the unit will be ON and Space Temp Control Mode,
Run Status VIEW SPT.M=2 (Hi Cool).
If the sensor is being used to support space temperature re-
set, the function will be disabled and the unit will continue to
run.
Reset Method: Automatic, once the condition resolves.
Possible Causes: If this condition is encountered, check the
following items:
• Check for a faulty thermistor.
• Check for a wiring error.
• Check to see that the override button has not perma-
nently shorted the sensor. Holding the button down too
long for an override period will cause this alarm.
T082 — Space Temperature Offset Sensor Failure
Criteria for Trip: This alert occurs when the space temperature
offset potentiometer is outside the range of –40 to 356 F (–40
to 180 C).
Action To Be Taken: Space temperature offset function will be
disabled. The unit will run under normal control without the
space temperature offset.
Reset Method: Automatic, once the condition resolves.
Possible Causes: If this condition is encountered, check the
following items:
• Check for a faulty offset potentiometer.
• Check for a wiring error.
T090 — Circuit A Discharge Pressure Transducer Failure
T091 — Circuit B Discharge Pressure Transducer Failure
Criteria for Trip: Transducer reading is outside the range of
0.0 to 667.0 psig (0.0 to 4599 kPa).
Action To Be Taken: Circuit is shut down.
Reset Method: Automatic, once the condition resolves.
Possible Causes: If this condition is encountered, check the
following items:
• Check for a faulty transducer.
• Check for a wiring error.
• Check the Main Base Board transducer channel for
proper operation.
T092 — Circuit A Suction Pressure Transducer Failure
T093 — Circuit B Suction Pressure Transducer Failure
Criteria for Trip: Transducer reading is outside the range of
0.0 to 420.0 psig (0.0 to 2896 kPa).
Action To Be Taken: Circuit is shut down.
Reset Method: Automatic, once the condition resolves.
Possible Causes: If this condition is encountered, check the
following items:
• Check for a faulty transducer.
• Check for a wiring error.
• Check the Main Base Board transducer channel for
proper operation.
T094 — Discharge Gas Thermistor Failure
Criteria for Trip: The following conditions must be true:
1. The unit must have a digital compressor installed and en-
abled on circuit A.
2. Discharge gas temperature is outside the range of –40 to
350 F (–40 to 177 C).
Action To Be Taken: The digital compressor operation is dis-
continued.
Reset Method: Automatic, once the condition resolves.
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