What can cause an OCL short circuit fault on the ATV21 or ATV212 drives?


04 September 2023

OCL fault on the ATV21/ATV212 drives

Product Line:
Altivar ATV21 and ATV212 including the S-Flex enclosed drives.


The ATV212 drive is tripping on OCL fault when they try and run the motor.

OCL means phase to phase output short circuit.  The motor impedance to ground is low.
Troubleshooting tips:
Try dropping the motor leads and meggering out the motor with a 1kv meggering if the motor checks out ok

If you need to run the drive open circuit without the motor connected:
Turn off the Drive and wait until the DC bus caps have discharged.
Turn off OPL ( F605) , set to 0  then set up F307 to 2
Now with the motor disconnected  you can run the VFD open circuit at 20  40 and 60hz.  Check your output voltage at each stage.