Hitachi Under V. fault code meaning

Series: HFC-VWS

Under power supply voltage

AC drive

Meaning: When the input line voltage drops the control circuit does not function correctly (insufficient base current, motor overheat, insufficient torque), so the output is cut off. Causes: momentary power loss or voltage fluctuation; input disconnect device / contactor. | Correct the problem in the power distribution system; replace the defective equipment.

Possible causes

Source: Hitachi HFC-VWS Instruction Manual P50