Specifications

79
Table 92 — Alert and Alarm Codes
LEGEND
ALARM OR
ALERT
NUMBER
DESCRIPTION ACTION TAKEN BY CONTROL
RESET
METHOD
PROBABLE CAUSE
A051
A051 Circuit A, Compressor 1 Current Detected After
Shutdown
Turn off all compressors Manual Welded Contact
P051 Compressor A1 Safety Trip Add strike to Compressor
Automatic
(max 3)
High pressure switch, compressor
current, wiring error
T051 Circuit A, Compressor 1 Failure Compressor locked off Manual Exceeded 3 strike limit
A052 Circuit A, Compressor 2 Current Detected After Shutdown Turn off all compressors Manual Welded Contact
P052 Circuit A, Compressor 2 Failure Add strike to Compressor
Automatic
(max 3)
High pressure switch, compressor
current, wiring error
T052 Circuit A, Compressor 2 Failure Compressor locked off Manual Exceeded 3 strike limit
A055 Circuit B, Compressor 1 Current Detected After Shutdown Turn off all compressors Manual Welded Contact
P055 Circuit B, Compressor 1 Failure Add strike to Compressor
Automatic
(max 3)
High pressure switch, compressor
current, wiring error
T055 Circuit B, Compressor 1 Failure Compressor locked off Manual Exceeded 3 strike limit
A056 Circuit B, Compressor 2 Current Detected After Shutdown Turn off all compressors Manual Welded Contact
P056 Circuit B, Compressor 2 Failure Add strike to Compressor
Automatic
(max 3)
High pressure switch, compressor
current, wiring error
T056 Circuit B, Compressor 2 Failure Compressor locked off Manual Exceeded 3 strike limit
T064 Circuit A Saturated Condensing Thermistor Failure Use OAT for head pressure control Automatic Faulty thermistor or wiring error
T065 Circuit B Saturated Condensing Thermistor Failure Use OAT for head pressure control Automatic Faulty thermistor or wiring error
T072 Remote Setpoint/Reset Input Failure Unit Shutdown Automatic Faulty remote input on CEM board
T073 Outside Air Temperature Thermistor Failure Stop use of economizer Automatic Faulty thermistor or wiring error
T074 Space Temperature Thermistor Failure Unit Shutdown Automatic Faulty thermistor or wiring error
T075 Return Air Thermistor Failure Continue to run unit Automatic Faulty thermistor or wiring error
T076 Outside Air Relative Humidity Sensor Failure Use OAT changeover control Automatic Faulty sensor or wiring error
T078 Return Air Relative Humidity Sensor Failure
Use differential drybulb
changeover
Automatic Faulty sensor or wiring error
T082 Space Temperature Offset Sensor Failure
Use Space temperature without
offset
Automatic Faulty sensor or wiring error
T092 Circuit A Suction Pressure Transducer Failure Stop circuit Automatic Faulty sensor, wiring error
T093 Circuit B Suction Pressure Transducer Failure Stop circuit Automatic Faulty sensor, wiring error
T110 Circuit A Loss of Charge Stop circuit Manual Low refrigerant charge
T111 Circuit B Loss of Charge Stop circuit Manual Low refrigerant charge
A120 Circuit A Low Saturated Suction Temperature Alarm. Stop circuit Manual
Low refrigerant charge, low airflow,
dirty coil, broken fan belt, TXV
problem
T120 Circuit A Low Saturated Suction Temperature Alert. Stop circuit Automatic
Low refrigerant charge, low airflow,
dirty coil, broken fan belt, TXV
problem
A121 Circuit B Low Saturated Suction Temperature Alarm. Stop circuit Manual
Low refrigerant charge, low airflow,
dirty coil, broken fan belt, TXV
problem
T121 Circuit B Low Saturated Suction Temperature Alert. Stop circuit Automatic
Low refrigerant charge, low airflow,
dirty coil, broken fan belt, TXV
problem
T122 Circuit A High Saturated Suction Temperature Stop circuit Manual TXVproblem
T123 Circuit B High Saturated Suction Temperature Stop circuit Manual TXVproblem
T126 Circuit A High Head Pressure Stop circuit Automatic
Dirty condenser, condenser fan
failure
T127 Circuit B High Head Pressure Stop circuit Automatic
Dirty condenser, condenser fan
failure
A150 Unit is in Emergency Stop Stop units Manual External shutdown command
T153 Real Time Clock Hardware Failure Stop unit Manual Control Board failure, check lights
A154 Serial EEPROM Hardware Failure Stop unit Manual Control Board failure, check lights
T155 Serial EEPROM Storage Failure Error Stop unit Manual Control Board failure, check lights
A156 Critical Serial EEPROM Storage Failure Error Stop unit Manual Control Board failure, check lights
A157 A/D Hardware Failure Stop unit Manual Control Board failure, check lights
A171
Loss of communications with the staged Gas control
board
Stop gas heat Automatic Control Board failure, check lights
A172 Loss of communications with the Control Expansion Board Stop options on CEM Automatic Control Board failure, check lights
A173 Loss of communications with the ECB1 Board Stop economizer & power exh Automatic Control Board failure, check lights
A174 Loss of communications with the ECB2 board Stop unit Automatic Control Board failure, check lights
T177 4-20 MA Demand Limit Failure Stop demand limiting Automatic Input failure, wiring error
T178 4-20 MA Static Pressure Reset Fail Stop static pressure reset Automatic Input Failure, wiring error
A200 Linkage Timeout Error - Loss of Communication Stop unit Manual Wiring errors, board failures
T210 Building Pressure Transducer Failure Close economizer, stop exhaust Automatic Sensor failure, wiring error
T211 Static Pressure Transducer Failure Stop unit Automatic Sensor failure, wiring error
T220 Indoor Air Quality Sensor Failure Stop IAQ control Automatic Sensor failure, wiring error
T221 Outdoor Air Quality Sensor Failure Use a default value for IAQ Automatic Sensor failure, wiring error
T229 Economizer Minimum Position Override Sensor Failure
Use software configured
minimum
Automatic Input failure, wiring error
T245 Outside Air CFM Sensor Failure not used at this time not used
T246 Supply Air CFM Sensor Failure not used at this time not used
T247 Return Air CFM Sensor Failure not used at this time not used
A—Alarm
P—Pre-Alert
T—Alert