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ATS48 with a shorting contactor detects an OCF fault when stopping.

When a stop command is issued, the soft starter faults with OCF before the motor starts to slow down.

Product Line:
ATS48 soft starters.

ATS48 soft starters with shorting contactor.

Improper control of shorting contactor.

The shorting contactor should be connected to the R2 relay on the soft starter.  This relay is dedicated for opening and closing the shorting contactor.   In this instance, the customer was using the R3 relay to control their shorting contactor and had the R3 function programmed to RNI (Motor powered).    When they sent the command to stop, via their HMI, the starter began ramping down the SCRs to slow the motor, but the shorting contactor was still closed.  RNI function will keep the relay closed until the motor comes to a complete stop.  This is not possible with the shorting contactor closed.  The starter detected that the motor current was not decreasing, as it should when stopping the motor, and detected this as an Over Current Fault.    Connecting the shorting contactor to the R2 relay corrected the problem.
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