Carrier WeatherMaker 48A2020 Controls, Start-up, Operation, Service And Troubleshooting Instructions

102Table 99 — Alert and Alarm CodesALARM ORALERTNUMBERDESCRIPTION ACTION TAKEN BY CONTROL RESETMETHOD PROBABLE CAUSEA051 Circuit A, Compressor 1 Stuck On Failure Turn off all compressors Manual Welded contactP051 Circuit A, Compressor 1 Failure Add strike to compressor Automatic(max 3)High pressure switch, compressorcurrent, wiring errorT051 Circuit A, Compressor 1 Failure Compressor locked off Manual Exceeded 3 strike limitA052 Circuit A, Compressor 2 Stuck On Failure Turn off all compressors Manual Welded contactP052 Circuit A, Compressor 2 Failure Add strike to compressor Automatic(max 3)High pressure switch, compressorcurrent, wiring errorT052 Circuit A, Compressor 2 Failure Compressor locked off Manual Exceeded 3 strike limitA055 Circuit B, Compressor 1 Stuck On Failure Turn off all compressors Manual Welded contactP055 Circuit B, Compressor 1 Failure Add strike to compressor Automatic(max 3)High pressure switch, compressorcurrent, wiring errorT055 Circuit B, Compressor 1 Failure Compressor locked off Manual Exceeded 3 strike limitA056 Circuit B, Compressor 2 Stuck On Failure Turn off all compressors Manual Welded contactP056 Circuit B, Compressor 2 Failure Add strike to compressor Automatic(max 3)High pressure switch, compressorcurrent, wiring errorT056 Circuit B, Compressor 2 Failure Compressor locked off Manual Exceeded 3 strike limitT064 Circuit A Saturated Temperature Transducer Failure Stop circuit Automatic Faulty sensor, wiring errorT065 Circuit B Saturated Temperature Transducer Failure Stop circuit Automatic Faulty sensor, wiring errorT072 Evaporator Discharge Reset Sensor Failure Unit shutdown Automatic Faulty remote input on CEM boardT073 Outside Air Temperature Thermistor Failure Stop use of economizer Automatic Faulty thermistor or wiring errorT074 Space Temperature Thermistor Failure Unit shutdown Automatic Faulty thermistor or wiring errorT075 Return Air Thermistor Failure Continue to run unit Automatic Faulty thermistor or wiring errorT076 Outside Air Relative Humidity Sensor Failure Use OAT changeover control Automatic Faulty sensor or wiring errorT077 Space Relative Humidity Sensor Failure Use differential dry bulb changeover Automatic Faulty sensor or wiring errorT078 Return Air Relative Humidity Sensor Failure Use differential dry bulb changeover Automatic Faulty sensor or wiring errorT082 Space Temperature Offset Sensor Failure Use Space temperature without offset Automatic Faulty sensor or wiring errorT090 Circuit A Discharge Pressure Transducer Failure Stop circuit Automatic Faulty sensor, wiring errorT091 Circuit B Discharge Pressure Transducer Failure Stop circuit Automatic Faulty sensor, wiring errorT092 Circuit A Suction Pressure Transducer Failure Stop circuit Automatic Faulty sensor, wiring errorT093 Circuit B Suction Pressure Transducer Failure Stop circuit Automatic Faulty sensor, wiring errorT110 Circuit A Loss of Charge Stop circuit Manual Low refrigerant chargeT111 Circuit B Loss of Charge Stop circuit Manual Low refrigerant chargeA120 Circuit A Low Saturated Suction Temperature Alarm. Stop circuit Manual Low refrigerant charge, low airflow, dirtycoil, broken fan belt, TXV problemP120 Circuit A Low Saturated Suction Temp-Comp A2 Shutdown Compressor A2 shutdown Automatic Low refrigerant charge, low airflow, dirtycoil, broken fan belt, TXV problemT120 Circuit A Low Saturated Suction Temperature Alert. Stop circuit Automatic Low refrigerant charge, low airflow, dirtycoil, broken fan belt, TXV problemA121 Circuit B Low Saturated Suction Temperature Alarm. Stop circuit Manual Low refrigerant charge, low airflow, dirtycoil, broken fan belt, TXV problemP121 Circuit B Low Saturated Suction Temp-Comp B2 Shutdown Compressor B2 shutdown Automatic Low refrigerant charge, low airflow, dirtycoil, broken fan belt, TXV problemT121 Circuit B Low Saturated Suction Temperature Alert. Stop circuit Automatic Low refrigerant charge, low airflow, dirtycoil, broken fan belt, TXV problemT122 Circuit A High Saturated Suction Temperature (or at Startup) Stop circuit Manual TXV problem, high loadT123 Circuit B High Saturated Suction Temperature (or at Startup) Stop circuit Manual TXV problem, high loadP126 Circuit A High Head Pressure, Comp Shutdown Circuit staged down Automatic Dirty condenser, condenser fan failure,system overchargedT126 Circuit A High Head Pressure Alert Stop circuit Automatic Dirty condenser, condenser fanfailure, system overchargedA126 Circuit A High Head Pressure Alarm Stop circuit Manual Dirty condenser, condenser fan failure,system overchargedP127 Circuit B High Head Pressure Comp Shutdown Circuit staged down Automatic Dirty condenser, condenser fan failure,system overcharged.T127 Circuit B High Head Pressure Alert Stop circuit Automatic Dirty condenser, condenser fanfailure, system overchargedA127 Circuit B High Head Pressure Alarm Stop circuit Manual Dirty condenser, condenser fan failure,system overchargedT128 Digital Scroll High Discharge Temperature Alert Digital compressor A1 shutdown Automatic Refrigeration problemA128 Digital Scroll High Discharge Temperature Alarm Digital compressor A1 locked off Manual Refrigeration problemA140 Reverse Rotation Detected Stop unit Manual Incorrect compressor wiringA150 Unit is in Emergency Stop Stop unit Manual External shutdown commandA151 Illegal Configuration - More Than Two Elec. Heat Stages Stop unit Manual Reconfigure the electric heat stageT153 Real Time Clock Hardware Failure Stop unit Manual Control Board failure, check lightsA154 Serial EEPROM Hardware Failure Stop unit Manual Control Board failure, check lightsT155 Serial EEPROM Storage Failure Error Stop unit Manual Control Board failure, check lightsA156 Critical Serial EEPROM Storage Failure Error Stop unit Manual Control Board failure, check lightsA157 A/D Hardware Failure Stop unit Manual Control Board failure, check lightsA168 Low Ambient Control Board (SCB2) Comm Failure Cooling is disabled Automatic Incorrect wiring, power lossA169 Expansion Valve Control Board Comm Failure Humidi-MiZer Control Disabled Automatic Incorrect wiring, power lossA171 Staged Gas Control Board Comm Failure Stop gas heat Automatic Control Board failure, check lightsA172 Staged Gas Control Board 2 (SCB2) Comm Failure Stop cooling function Automatic Incorrect wiring, power lossA173 ECB1 Board Communication Failure Stop economizer & power exh Automatic Control Board failure, check lightsA174 ECB2 Board Communication Failure Stop unit Automatic Control Board failure, check lightsT177 4-20 mA Demand Limit Failure Stop demand limiting Automatic Input failure, wiring errorT178 4-20 mA Static Pressure Reset/VFD Fail Stop static pressure reset/VFD Automatic Input Failure, wiring errorA179 Circuit A ODF VFD Failure Circuit A compressor shutdown Manual VFD fault, verify driveA180 Circuit B ODF VFD Failure Circuit B compressor shutdown Manual VFD fault, verify drive