Specifications
Table 43 -- ComfortLink TM Alarm Codes
ALARM OR
ALERT DESCRIPTION ACTION TAKEN RESET PROBABLE CAUSE
NUMBER BY CONTROL METHOD
T051 Compressor A1 Safety Trip Add Strike for Circuit A Automatic errorHigh-pressureswitch open Compressor internal protection open. Wiring
Compressor A1 Current Detected After Turnoff Turn off all compressors Automatic Welded contactor
T052 Compressor A2 Safety Trip Add Strike for Circuit A Automatic High pressure switch open. Compressor internal protection open.
Wiring error.
Compressor A2 Current Detect After Turnoff Turn off all compressors Automatic Welded contactor
T055 Compressor B1 Safety Trip Add Strike for Circuit B Automatic errorHigh-pressureswitch open Compressor internal protection open. Wiring
Compressor B1 Current Detected After Turnoff Turn off all compressors Automatic Welded contactor
T059 Compressor Cl Safety Trip Add Strike for Circuit C Automatic High-pressure switch open Compressor internal protection open. Wiring
error
Compressor Cl Current Detected After Turnoff Turn off all compressors Automatic Welded contactor
Circuit A Saturated Condensing Tamp Thermistor Faulty, shorted, or open thermistor caused by wiring error or faose
T064 Failure Use OAT to control Outdoor fans Automatic connection.
T065 Circuit B Saturated Condensing Tamp Thermistor Use OAT to control Outdoor fans Automatic Faulty, shorted, or open thermistor caused by wiring error or faose
Failure connection.
Fauity, shorted, or open thermistor caused by wiring error or loose
TO73 Outdoor Air Temperature Thermistor Failure No cooling with economizer Automatic connection.
If U.CTL = 3, then no Fauity, shorted, or open thermistor caused by wiring error or loose
TO74 Space Temperature Thermistor Failure heating or coofing Automatic connection.
No cooling with economizer and Automatic Faulty, shorted, or open thermistor caused by wiring error or loose
TO75 Supply Air Temperature Thermistor Failure No adaptive compressor staging connection.
If RAT.S = Yes, then Automatic Faulty, shorted, or open thermistor caused by wiring error or loose
TO76 Return Air Thermistor Failure no return air display connection.
If RH.S = Yes, then no Automatic Faulty sensor or wiring error
TO77 Space Relative Humidity Sensor Failure indoor humidity control
TO8O Circuit C Saturated Condensing Tamp Thermistor Use OAT to control Outdoor fans Automatic Faulty, shorted, or open thermistor caused by wiring error or faose
Failure connection.
T092 Circuit A Suction Pressure Transducer Failure Shutdown Circuit A Manual Faulty transducer, faulty 5-V power supply, or loose connection
T093 Circuit B Suction Pressure Transducer Failure Shutdown Circuit B Manual Faulty transducer, faulty 5-V power supply, or loose connection
TfOl Circuit C Suction Pressure Transducer Failure Shutdown Circuit C Manual Faulty transducer, faulty 5-V power supply, or loose connection
Compressor A1 Current Sensor Failure If CS.A1 = Enable, then no Automatic Faulty current sensor caused by wiring error or loose connection
T102 T051 current alarm
If CS.A2 = Enable, then no
Compressor A2 Current Sensor Failure T052 current alarm Automatic Fauity current sensor caused by wiring error or loose connection
T103 Compressor B1 Current Sensor Failure If CS.B1 = Enable, then no Automatic Fauity current sensor caused by wiring error or loose connection
T055 current alarm
T104 Compressor C1 Current Sensor Failure If CSC1 = Enable, then no Automatic Faulty current sensor caused by wiring error or loose connection
T059 current alarm
TI 10 Circuit A Loss of Charge Shutdown Circuit A Manual Low refrigerant or faulty suction pressure transducer
TI 11 Circuit B Loss of Charge Shutdown Circuit B Manual Low refrigerant or faulty suction pressure transducer
T126 Circuit A High Refrigerant Pressure Shutdown Circuit A Automatic An overcharged system, high outdoor ambient temperature coupled with
dirty outdoor coil, plugged filter drier, or a faulty high-pressure switch
An overcharged system, high outdoor ambient temperature coupled with
T127 Circuit B High Refrigerant Pressure Shutdown Circuit B Automatic dirty outdoor coil, plugged filter drier, or a faulty high-pressure switch
Low refrigerant charge, dirty filters, evaporator fan turning backwards,
T133 Circuit A Low Refrigerant Pressure Add Strike for Circuit A Automatic loose or broken fan belt, plugged filter drier, faulty transducer, exces-
sively cold return air. or stuck open economizer when the ambient fam-
_erature is low.
Low refrigerant charge, dirty filters, evaporator fan turning bacle_vards,
T134 Circuit B Low Refrigerant Pressure Add Strike for Circuit B Automatic loose or broken fan belt, plugged filter drier, faulty transducer, exces-
sively cold return air. or stuck open economizer when the ambient fam-
_erature is low.
T140 Circuit C Loss of Charge Shutdown Circuit C Manual Low refrigerant or faulty suction pressure transducer
T141 Circuit C Low Refrigerant Pressure Add Strike for Circuit C Automatic Low refrigerant charge, dirty fi]fars, evaporator fan turning backwards,
loose or broken fan belt, plugged filter drier, faulty transducer, exces-
sively cold return air. or stuck open economizer when the ambient fam-
_erature is faw.
T142 Circuit C High Refrigerant Pressure Shutdown Circuit C Automatic An overcharged system, high outdoor ambient temperature coupled with
dirty outdoor coil, plugged filter drier, or a faulty high-pressure switch
T143 Circuit A Failure To Pressurize Add Strike for Circuit A Automatic Wiring causing reverse rotation or faulty compressor
T144 Circuit B Failure To Pressurize Add Strike for Circuit B Automatic Wiring causing reverse rotation or faulty compressor
T145 Circuit C Failure To Pressurize Add Strike for Circuit C Automatic Wiring causing reverse rotation or faulty compressor
No time and date
T153 Real Timeclock Hardware Failure schedule operation Automatic No time/date configured, software failure, or MBB failure
A154 Serial BBPROM Hardware Failure Unit Shutdown Automatic Software failure or MBB failure
T155 Serial BBPROM Storage Failure Error Unit operation errors Automatic Software failure or MBB failure
A156 Critical Serial EEPROM Storage Fail Error Unit Shutdown Automatic Software failure or MBB failure
A157 AJD Hardware Failure Unit Shutdown Automatic Software failure or MBB failure
A163 Circuit A Down Due to Failure Shutdown Circuit A Manual Circuit has 3 strikes or has been locked out by another alarm
A164 Circuit B Down Due to Failure Shutdown Circuit B Manual Circuit has 3 strikes or has been locked out by another alarm
A165 Circuit C Down Due to Failure Shutdown Circuit C Manual Circuit has 3 strikes or has been locked out by another alarm
T179 Loss of communication with the Economizer No economizer operation Automatic Communication wiring problem with BCB or faulty MBB or BCB
Control Board
T180 Loss of communication with the Economizer No economizer operation Automatic Communication wiring problem with actuator
Actuator
A404 Fire Shutdown Unit Shutdown Automatic Smoke detected by smoke detector
T408 Dirty Filter -- Automatic Dirty Filter
If IDF.F = YES,
Fan Status Switch ON, Contactor OFF If ]DFF = Yes, then Manual, Bad Fan Status Switch.
then Unit Shutdown othe/_vise Configuration incorrect
automatic
T409 If IDF.F = YES, Tripped Circuit Breaker
If ]DFF = Yes, then Manual, Broken belt.
Fan Status Switch OFF, Contactor ON then Unit Shutdown othel_vise Bad indoor fan motor.
automatic Configuration incorrect. Bad fan status switch
LEGEND
ECB -- Economizer Control Board MBB -- Main Base Board
IGC -- Integrated Gas Controller OAT -- Outdoor-Air Thermistor
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