CBF , Circuit Breaker Fauiler
CBF , Circuit Breaker Fauiler
(OP)
In protection system we usually consider CBF protection for each circuit breacker. If CBF operates in one CB ,it sends trip to all other adjacent CBs.
The question is whether the CBF function in other adjacent CBs which received this trip must be activated or not? why?
Do you have any opinion?
Regards,
The question is whether the CBF function in other adjacent CBs which received this trip must be activated or not? why?
Do you have any opinion?
Regards,






RE: CBF , Circuit Breaker Fauiler
RE: CBF , Circuit Breaker Fauiler
1-I read the spec of two famous power engineering consultant co. in my country. Both of them indicate that the CBF must not initiate CBF in adjacent CBs.
2- I don't know exactly, but i guess breaker failure in other CBs will be cleared by the other protection relating to those CBs.
3- In all schemes I have seen the CBF initiate CBF of adjacent CBs just when for each CB, two CBF were considered. i think it is because of that considering two CBF makes high reliability for protection system and prevents malfunction of CBF. and make us sure , CBF just initiate when both CBF of main CB initiate it and CBF does not send trip because of malfunction.
RE: CBF , Circuit Breaker Fauiler
Breaker failure should always cascade. If it is correct
for the protection to trip the breaker, it is also correct
for the breaker-fail scheme to be initiated.
Thanks,
Submonkey
RE: CBF , Circuit Breaker Fauiler
The Guide for Breaker Failure Protection of Power Circuit Breakers C37.119 suggests in section 8.3 that two CBF scheme problems are more likely than two failed breakers.
RE: CBF , Circuit Breaker Fauiler
RE: CBF , Circuit Breaker Fauiler
i read the same that two probability of two cbf malfunction operation is higher than probability of two breaker failure, so it is suggested do not cascade cbf.
what is C37.119?
RE: CBF , Circuit Breaker Fauiler
RE: CBF , Circuit Breaker Fauiler
It was interesting that the original breakers did eventually trip. It would be interesting to find out about the fault clearing ability of a breaker is when it operates slower than expected.
RE: CBF , Circuit Breaker Fauiler
and if i must not cascade it should i send the trip directly to the breakers or depend on the other breakers protection to see the fault?
bacon4life please send me the link of this paper
RE: CBF , Circuit Breaker Fauiler
Welcome to the forum, but you are much more likely to get an answer about the P122 if you start a new thread instead of hijacking this one.
RE: CBF , Circuit Breaker Fauiler
Sorry!