28 September 2021
OCA fault on ATV21/ATV212 drives?Product line:
Altivar 212, ATV212, S-FlexEnvironment:
All models, all serial numbers.Cause:
Overcurrent during start-up or ground faultResolution:
OCA – short-circuit detected in drive output inverter stage during motor startup
Check that Line and Load cables are connected to the proper terminals. Line cables go to R/L1, S/L2 and T/L3. Load or motor cables go to U/T1, V/T2 and W/T3.
Disconnect the motor leads from the drive. Using a 1000V Megger, check the motor and motor leads for shorts or ground fault.
Try a voltage balance test. With the motor leads still disconnected, set parameter F605 to 0 (disable Output Phase Failure). Run the drive at 20Hz, 40Hz and 60Hz. At each speed measure the line to line output voltages to see if they are balanced.