What this code means

Before to switch the main contactor on, the SW turns on sequence the Bottom side Power Mosfets and expects the phase V voltage falls to GND value. If the phase V remains high level this alarm occurs.

Applies to: ZAPI AC-0 SSL Sensored inverter (traction & pump configuration).

Possible causes / checks (from the source)

Two possibilities: - At least a motor phase is not connected to the controller or broken. - A Power Failure (e.g. a Bottom side Power Mosfet opened) or a Logic Failure occurred in the controller. In this case it is necessary to replace the controller.

Need the part?

If diagnosis points to a failed sensor, solenoid, controller or harness part, send us the code (MDI-PRC 31), machine model and serial number — we quote genuine and OEM replacement parts for export.