OEM Service Manual: Carrier 30XA Service Manual (Form 30XA-6SI). Available through Carrier Commercial Systems technical support or partnered distributors.
39 codes
| Fault Code | Alarm Description | Severity | Probable Causes | Action |
|---|---|---|---|---|
| 1 | Evaporator entering fluid thermistor failure | Warning | Thermistor sensor damaged or out of calibration | View Details → |
| 2 | Evaporator leaving fluid thermistor failure | Warning | Thermistor element degraded or failed | View Details → |
| 3 | Condenser entering fluid thermistor failure | Warning | Water-cooled condenser thermistor sensor failure | View Details → |
| 7 | Outdoor temperature sensor fault | Warning | Ambient temperature sensor exposed to moisture ingress | View Details → |
| 9 | Compressor A1 discharge gas temperature sensor fault | Warning | Discharge temperature sensor element failure | View Details → |
| 14 | Discharge pressure transducer failure, circuit A | Warning | Pressure transducer diaphragm damaged | View Details → |
| 16 | Suction pressure transducer failure, circuit A | Warning | Transducer sensing port blocked with debris | View Details → |
| 30 | Loss of communication with SCPM A1 board | Warning | CCN communication cable damaged or disconnected | View Details → |
| 41 | Unit emergency stop | Critical | Emergency stop button activated | View Details → |
| 44 | Discharge pressure circuit A too high | Warning | Condenser fouling or insufficient airflow | View Details → |
| 54 | Oil level circuit A low | Warning | Refrigerant charge leaking oil from system | View Details → |
| 56 | Low saturated suction temperature, circuit A | Warning | Low refrigerant charge | View Details → |
| 68 | Low oil pressure, compressor A1 | Critical | Oil pump failure or internal wear | View Details → |
| 72 | Evaporator frost protection | Critical | Evaporator water flow too low or stopped | View Details → |
| 75 | Evaporator water flow control failure | Warning | Water flow switch stuck or failed | View Details → |
| 77 | High current, compressor A1 | Critical | Compressor motor bearing failure | View Details → |
| 81 | Pump 1 fault | Warning | Chilled water pump motor overload tripped | View Details → |
| 87 | Reset of safety control | Info | Manual reset of any safety device | View Details → |
| 4 | Condenser leaving fluid thermistor failure | Warning | Condenser leaving water thermistor sensor failure | View Details → |
| 5 | Defrost thermistor failure | Warning | Defrost temperature sensor element failure | View Details → |
| 6 | Remote temperature sensor failure | Warning | Remote space temperature sensor failure | View Details → |
| 8 | Compressor A2 discharge gas temperature sensor fault | Warning | Discharge temperature sensor element failure on compressor A2 | View Details → |
| 10 | Compressor B1 discharge gas temperature sensor fault | Warning | Discharge temperature sensor element failure on circuit B | View Details → |
| 15 | Discharge pressure transducer failure, circuit B | Warning | Pressure transducer diaphragm damaged on circuit B | View Details → |
| 17 | Suction pressure transducer failure, circuit B | Warning | Transducer sensing port blocked on circuit B | View Details → |
| 20 | Compressor motor overload, circuit A | Critical | Compressor motor drawing excessive current | View Details → |
| 21 | Compressor motor overload, circuit B | Critical | Compressor B motor overload | View Details → |
| 31 | Loss of communication with SCPM B1 board | Warning | CCN communication cable to circuit B damaged | View Details → |
| 38 | Power supply error | Warning | Phase voltage imbalance exceeding 2% | View Details → |
| 45 | Discharge pressure circuit B too high | Warning | Circuit B condenser fouling or insufficient airflow | View Details → |
| 46 | Suction pressure circuit A too low | Warning | Low refrigerant charge on circuit A | View Details → |
| 47 | Suction pressure circuit B too low | Warning | Low refrigerant charge on circuit B | View Details → |
| 55 | Oil level circuit B low | Warning | Refrigerant leak on circuit B carrying oil | View Details → |
| 57 | Low saturated suction temperature, circuit B | Warning | Low refrigerant charge on circuit B | View Details → |
| 69 | Low oil pressure, compressor B1 | Critical | Oil pump failure or wear on compressor B1 | View Details → |
| 73 | Compressor A1 running but no current detected | Warning | Compressor contactor not pulling in for A1 | View Details → |
| 76 | Cooling tower water temperature too high | Warning | Cooling tower fan not operating | View Details → |
| 82 | Pump 2 fault | Warning | Secondary chilled water pump motor overload tripped | View Details → |
| 85 | High compressor motor temperature, compressor A1 | Warning | Compressor motor cooling insufficient | View Details → |
Disclaimer: All Carrier 30XA fault code data is for reference only. Do not use this information to replace certified professional HVAC technician judgment. Always refer to original OEM official service manual.