|Alarm Code||H11, H12, H21, H22|
H11: Constant speed compressor 2 overcurrent alarm
Hx1: During operation, the compressor current value exceeded 20 A for 30 seconds or longer. However this alarm is not detected for 4 seconds after the compressor starts.
Hx2: During operation, the compressor current value exceeded 29 A for 4 seconds or longer. However this alarm is not detected for 2 seconds after the compressor starts.
1. Compressor failure (partially locked)
Trouble: Current value during operation greatly exceeds the value shown above.
Check: When the current for each phase is measured with a clamp meter or similar instrument, check that the current value for all phases is not high. If MG was forced ON (use caution), check that compressor noise will not occur or the compressor will not run with a groaning sound.
2. CT circuit failure, PCB failure
3. Missing power phase
Trouble: This alarm primarily occurs when the T-phase is missing. When the R-phase or S-phase is missing, CT trouble or PCB continuity trouble occur. However this may not be true in the case of a missing phase caused by magnet SW trouble.
Check: There is the possiblility of a magnet SW failure. Therefore, check the phase voltage at a location that is as close to the compressor as possible.
4. Low power voltage
Trouble: In most cases, this occurs when another constant-speed compressor (including compressors in other units) or other device starts. It also occurs when the power wiring is extremely long.
Check: Check the voltage between each of the phases. However if this trouble occurs when other devices or compressors start, then an oscilloscope is required.
5. PCB failure
6. If the cause is still unknown after checking the above, then it is possible that noise is the cause of the trouble. It is necessary to connect a PC or other instrument.