Trip Circuit Supervision

Circuit breaker manufacturers typically offer two types of auxiliary contacts : signal contacts and alarm contacts.

Signal contacts indicate by means of the contacts whether the breaker is in the open or closed positions.

Alarm contacts indicate by means of the contacts whether the breaker is tripped or not.

The logic scheme is something you will have to determine for yourself.

Dear all,

Just for example. The lamp L is for CB closed status and trip circuit supervision.

When CB is closed, and lamp L is ON, trip circuit is healthy.

If your protection relay supports this function, use it.

thanks. i got it and i accomplished it today. we use distance protection relay, it has got a lot of digital input (opto input). we connected trip output contacts of each phase to digital input's (-) polarity. (+) polarity is already direct connected. and we assign a output to that inputs with CB 52a. Here it is a trip circuit supervision but it is just supervise while CB is closed.

it is a cheap solve.

thanks for ur helps.

thanks. i got it and i accomplished it today. we use distance protection relay, it has got a lot of digital input (opto input). we connected trip output contacts of each phase to digital input's (-) polarity. (+) polarity is already direct connected. and we assign a output to that inputs with CB 52a. Here it is a trip circuit supervision but it is just supervise while CB is closed.

it is a cheap solve.

thanks for ur helps.

Dear all,

Yes, it is to supervise the trip circuit only while the CB is closed.

I have no idea how to monitor the trip circuit while the CB is open.

Regards

supervision of CBs is accomplished through an auxiliary contact fixed to the breakers....its usually called as SD or OF contact....the o/p terminals of this contact can be connected to indication lamp or alarm sensors.......the contacts are energised whenever the CBs r tripped......for schematics download mcb or mccb catalogues from abb or schneider

"Trip circuit supervision" means to me the periodic checking whether the trip circuit of a circuit breaker is really healthy, and will the CB trip in the event of a fault... do you mean this? If so, accessories for this purpose are usually avilable from major manufactureres of circuit breakers. One such device sends periodic pulses of small current to the trip circuit to see if there is any discontinuity. Is this what you mean?