What are possible causes for the ATS48 softstart to trip the breaker?


18 July 2022

ATS48 softstart trips the main breaker.

Product Line:
ATS48, Altistart 48

All models and serial numbers

Possible causes:
1.  The load is excessive
2.  Shorted SCR
3.  Shorting contactor is welded in the closed position
4. Incorrect settings on the breaker

If excessive load, you may need to upsize the motor and soft start.  Try increasing the acceleration time.  Decrease the load.
With the soft start powered down, perform static checks on the SCR's. If shorted SCR's, repair or replace.
If shorting contactor is welded, replace the shorting contactor.
Check SCRS of the softstart.  This can be done by following FAQ listed here: 
Dial proper trip settings on the breaker if present.