Why is the ATV312 tripping on SCF or short circuit fault on power up?


09 June 2022

ATV312 tripping SCF 

Product line:
Altivar 312, ATV312, ATV31

All models, all serial numbers 

The drive trips on a SCF or a Short Circuit Fault if the drive detects a short circuit on the output of the drive.       

-Make sure all of the motor parameters are set in the DRC menu to match the motor name plate.  
-Check to make sure you don't have a long cable run of more than 100 feet. If you do, we recommend installing a output load reactor.
-Test the drive operation without the motor connected; turn off OPL (output phase loss) in the FLT menu. Try running the drive open circuit at 15, 30, 45, and 60Hz checking the output voltage phase to phase with a true RMS digital meter for balance at each frequency level.
Set Output Phase Loss attachment

-Check the motor and cables connecting to the drive for shorts phase to phase and phase to ground. 
-Check connections in the motor junction box for proper wiring.  
-Install a motor protecting output filter or load reactor at the output of the drive.
-Reduce the switching frequency (SFR in the SEt- menu). 
Set switching frequency attachment

If the SCF fault occurs with no motor or wiring connected to the drive, the drive will need to be replaced.

Refer to the attached ATV312 Programming manual BBV46385.

Note: Similar steps apply to the ATV12, ATV11, ATV32 and other Altivar Drive Products.