Hitachi UTOPIA RAS-4HVRP2E - Page 293

10 Troubleshooting
Troubleshooting procedure
SMGB0136 rev.0 - 07/2021
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10
Alarm code
53
Inverter Error Signal Detection
• 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 IPM (transistor module) error, ground fault detection or step-out detection occurs, the compressor stops. The operation
automatically restarts after three minutes. If this occurs again six times in the next 30 minutes, this alarm code is
displayed.
Condition of Activation:
1 IPM (Fault) signal error
Main causes: Abnormal compressor current, abnormal IPM control voltage, short circuited IPM, and so on.
2 Speed abnormality
Main causes: Compressor phase loss, output U, V, W are open.
3 FOC output phase loss
Main causes: Compressor phase loss and so on.