circuit breaker contacts?

[Mike01]

Question on LVPCB's and accessories / contacts:

For aux. contacts is it a correct statement that if the breaker contacts change state regardless of how [ex.manual operation, shunt trip operation, or tripping function] then the a/b contacts change state respectively. if you were to monitor these points you would only know the contacts changed state but now the why or how.

For Overcurrent Trip Switch / Bell Alarms [with or without lockout], this contact only changes state when the breaker contacts open / trip due to a protective device function [ex. LTPU, LTD, STPU, STD, GFPU, GFD, INST., etc.] and when the overcurrent trip switch changes state so will the aux. contacts because the breaker contacts have changed state. If the breaker is operated via. a shunt trip it would not activate this contact.

so if you were to monitor a aux contact and a bell alarm and the breaker were to "trip" both the trip switch and the aux contacts would change state.

 

[sameguy]

Question on LVPCB's and accessories / contacts:

For aux. contacts is it a correct statement that if the breaker contacts change state regardless of how [ex.manual operation, shunt trip operation, or tripping function] then the a/b contacts change state respectively. if you were to monitor these points you would only know the contacts changed state but now the why or how.

For Overcurrent Trip Switch / Bell Alarms [with or without lockout], this contact only changes state when the breaker contacts open / trip due to a protective device function [ex. LTPU, LTD, STPU, STD, GFPU, GFD, INST., etc.] and when the overcurrent trip switch changes state so will the aux. contacts because the breaker contacts have changed state. If the breaker is operated via. a shunt trip it would not activate this contact.

so if you were to monitor a aux contact and a bell alarm and the breaker were to "trip" both the trip switch and the aux contacts would change state.

Am I missing the question?

 

[Jraef]

Question on LVPCB's and accessories / contacts:

For aux. contacts is it a correct statement that if the breaker contacts change state regardless of how [ex.manual operation, shunt trip operation, or tripping function] then the a/b contacts change state respectively. if you were to monitor these points you would only know the contacts changed state but now the why or how.

For Overcurrent Trip Switch / Bell Alarms [with or without lockout], this contact only changes state when the breaker contacts open / trip due to a protective device function [ex. LTPU, LTD, STPU, STD, GFPU, GFD, INST., etc.] and when the overcurrent trip switch changes state so will the aux. contacts because the breaker contacts have changed state. If the breaker is operated via. a shunt trip it would not activate this contact.

so if you were to monitor a aux contact and a bell alarm and the breaker were to "trip" both the trip switch and the aux contacts would change state.

Question highlighted.

Yes, it is a correct statement. The a/b contacts follow the power contact state, bell contacts only follow the trip bar state. So in a trip, both change state, in a normal power off, only the a/b contacts change state. that's how you can discriminate.

 

[ATSman]

Question highlighted.

Yes, it is a correct statement. The a/b contacts follow the power contact state, bell contacts only follow the trip bar state. So in a trip, both change state, in a normal power off, only the a/b contacts change state. that's how you can discriminate.

With the breaker closed, and you operate the breaker control switch (CS) and energize the shunt trip (air frame circuit breaker) are you not operating the trip bar to open the breaker?