What this code means

Before to switch the main contactor on, the SW turns on sequence the Top side Power Mosfets and expects the phase V voltage increases toward the rail capacitor value. If the phase V does not increases this alarm occurs. This alarm may occur also when the initial diagnosis is overcome, and so the Main Contactor is expected to be closed. Then, when the operator asks the truck moving but the +Batt terminal of the controller is lower voltage than the Battery voltage, this alarm occurs (Main Contactor has lost the contact although it is closed).

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

Possible causes / checks (from the source)

If the problem occurs before the Main Contactor closes, probably a Power failure (e.g. a Bottom side Power Mosfet short circuited or a Top side Power Mosfet broken) or a Logic Failure occurred in the controller. If the problem occurs when the operator turns the truck moving the problem is the Battery positive is not connected to the +Batt terminal of the controller (check the continuity of the main contactor). If the problem occurs permanently it is necessary to replace the controller.

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