Mitsubishi Electric · FR-E500 Inverter
This error code indicates a communication fault originating from the PU connector, specifically related to RS-485 communication. When the E.PUE fault occurs, the inverter's operation stops, and communication via the PU connector is interrupted. During this fault state, the inverter cannot be reset using a computer connected via the PU connector.
Click steps to track your progress.
Verify RS-485 bus voltage levels at terminals A and B of the PU connector.
Inspect physical integrity of the PU connector and its mating half.
Confirm termination resistor values (typically 120 ohms) are correctly installed at network ends.
Cycle power to the affected unit after verifying connections.
Test communication with a known good PU unit if available.