when transfer switch goes back to normal source voltage it pops the circuit breaker, I suspect the problem is that the generator output and the utility output are not exactly in phase with each other causing magnetic flux "clashes", that is flux decaying vs. flux buildup because the different voltage sources are out of phase.
We have had this problem in the past and a phase monitoring device was installed by the technician that services some of our transfer switches but the problem has reared its ugly head again.
I am trying to get my boss to replace the one step transfer switch with a dual step transfer switch that would allow the flux in the transformer to decay enough, say a 3 second delay so that when it does make contact with the utility power we do not pop the breaker.
any suggestions, comment, or ideas would be very helpful.
