(Hoping that Zog sees this)
I am wondering if someone can describe the closing sequence of a Masterpact NW breaker.
I have a situation where (sometimes) when the breaker is commanded to close via the close coil, it bangs, the charging motor runs, but it remains open. If attempted again it always successfully closes.
Careful monitoring of the closed contacts (OF/CE pair) shows they are NOT made on the first pass.
Are there any internal feedback mechanisms that would cause the breaker to immediately open? My guess is that it is looking for some closed confirmation and if not received, immediately re-opens.
No power was seen on the trip coil. We have an unusual closed transfer scheme where the paralleling has to be < 80 ms. At that time one can just barely hear the 2 separate operations of the main and tie breakers. In the case of our misbehaving breaker, there is no distinction of sound separation, it is one single bang. So I am guessing the open/close is occurring in < 50 ms maybe.
Thanks.
I am wondering if someone can describe the closing sequence of a Masterpact NW breaker.
I have a situation where (sometimes) when the breaker is commanded to close via the close coil, it bangs, the charging motor runs, but it remains open. If attempted again it always successfully closes.
Careful monitoring of the closed contacts (OF/CE pair) shows they are NOT made on the first pass.
Are there any internal feedback mechanisms that would cause the breaker to immediately open? My guess is that it is looking for some closed confirmation and if not received, immediately re-opens.
No power was seen on the trip coil. We have an unusual closed transfer scheme where the paralleling has to be < 80 ms. At that time one can just barely hear the 2 separate operations of the main and tie breakers. In the case of our misbehaving breaker, there is no distinction of sound separation, it is one single bang. So I am guessing the open/close is occurring in < 50 ms maybe.
Thanks.