Hitachi UTOPIA RAS-4HVRP2E - Page 292

10 Troubleshooting
Troubleshooting procedure
SMGB0136 rev.0 - 07/2021
290
Alarm code
51
Abnormality of Current Sensor for Inverter
• Thealarmcodeisashedonthe7-segmentdisplayoftheoutdoorunit.
• The alarm code is displayed on the wired controller of the indoor unit.
If abnormal current detection occurs, the compressor stops. The operation automatically restarts after three minutes. If
this occurs again twice in the next 30 minutes, this alarm code is displayed.
Condition of Activation:
1 Picking up circuit for inverter current is not central value before the compressor starts operation.
2 Inverter secondary current es excessively low when the compressor starts operation.
Yes
No
Abnormal
Normal
Restart operation
How does compressor
operate when restarted?
Compressor stops immediately at
low frequency
“P7” indication appears without
compressor operation
Inverter PCB is faulty.
Replace it.
Is coil resistance of
compressor normal?
Replace compressor
Check inverter PCB Replace inverter PCB
Replace wiring for inverter PCB