What can cause an output phase fault (OPF) on an ATV312 or ATV31?


21 July 2022

OPF on Altivar 31/312 Drives

Product Line:

All models and serial numbers

This fault occurs when the drive has been commanded to run the motor but no or very little output current is detected by the drive.

Verify that the all three motor leads are properly connected to the drive.  Determine if there is a disconnect at the motor that could be open or a contactor between the drive and the motor that has not closed.  Loss of one leg or a significant imbalance of current between legs will cause the drive to signal output phase loss. The motor and motor leads should be Megger tested at 1,000 volts.
In some applications small motors are used and their current draw is below what the drive considers normal based on the motor information programmed in the drive.  The output phase loss detection can be disabled if there is no impact to the application.