OEM Service Manual: Carrier 30HXC Service Manual (Form 30HXC-7SI). Available through Carrier Commercial Systems technical support.
30 codes
| Fault Code | Alarm Description | Severity | Probable Causes | Action |
|---|---|---|---|---|
| 1 | Evaporator entering fluid thermistor failure | Warning | Thermistor sensor resistance drift | View Details → |
| 7 | Outdoor temperature sensor fault | Warning | Sensor moisture ingress | View Details → |
| 10 | Compressor A2 discharge gas temperature sensor fault | Warning | Discharge temperature sensor failure | View Details → |
| 14 | Discharge pressure transducer failure, circuit A | Warning | Transducer element failure | View Details → |
| 16 | Suction pressure transducer failure, circuit A | Warning | Transducer sensing port blocked | View Details → |
| 30 | Loss of communication with SCPM A1 board | Warning | CCN bus cable fault | View Details → |
| 41 | Unit emergency stop | Critical | Emergency stop activated | View Details → |
| 44 | Discharge pressure circuit A too high | Warning | Condenser water flow low | View Details → |
| 54 | Oil level circuit A low | Warning | Oil loss through leak | View Details → |
| 56 | Low saturated suction temperature, circuit A | Warning | Low refrigerant charge | View Details → |
| 68 | Low oil pressure, compressor A1 | Critical | Oil pump wear | View Details → |
| 72 | Evaporator frost protection | Critical | Low water flow | View Details → |
| 3 | Condenser entering fluid thermistor failure | Warning | Condenser water thermistor sensor failure | View Details → |
| 4 | Condenser leaving fluid thermistor failure | Warning | Condenser leaving water thermistor sensor failure | View Details → |
| 11 | Compressor B1 discharge gas temperature sensor fault | Warning | Discharge temperature sensor failure on circuit B | View Details → |
| 15 | Discharge pressure transducer failure, circuit B | Warning | Circuit B discharge transducer element failure | View Details → |
| 17 | Suction pressure transducer failure, circuit B | Warning | Circuit B suction transducer port blocked | View Details → |
| 20 | Compressor motor overload, circuit A | Critical | Motor drawing excessive current | View Details → |
| 21 | Compressor motor overload, circuit B | Critical | Circuit B compressor motor overload | View Details → |
| 31 | Loss of communication with SCPM B1 board | Warning | CCN cable to circuit B damaged | View Details → |
| 38 | Power supply error | Warning | Phase voltage imbalance | View Details → |
| 45 | Discharge pressure circuit B too high | Warning | Circuit B condenser fouling | View Details → |
| 46 | Suction pressure circuit A too low | Warning | Low refrigerant on circuit A | View Details → |
| 55 | Oil level circuit B low | Warning | Oil loss on circuit B | View Details → |
| 69 | Low oil pressure, compressor B1 | Critical | Oil pump B1 wear | View Details → |
| 73 | Compressor A1 running but no current | Warning | Contactor A1 not pulling in | View Details → |
| 76 | Condenser water temperature too high | Warning | Cooling tower issue | View Details → |
| 85 | High compressor motor temperature A1 | Warning | Motor cooling insufficient | View Details → |
| 88 | Fault code memory error | Warning | Control board memory corruption | View Details → |
| 89 | Real time clock error | Warning | RTC battery depleted | View Details → |
Disclaimer: All Carrier 30HXC 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.