Circuit breaker auxiliary contacts

[sigshane]

Hello folks. I am working through the DC control print for our generator output circuit breakers. Now, I have heard many people say they "know", or "think", but I want absolute, documented information on "a", "b", but especially "aa", "bb", and "ab" contacts, concerning circuit breaker main contact movement and/or position.

I know what a and b are. a should match the main contacts, and b should be opposite them. But what about aa? bb? What do they do exactly?

The tossed around 'knowledge' here about "ab" is they are closed when the main contacts are between open and closed states, which makes sense, since they are used in a breaker failure circuit here.

What I need is a solid reference to these contacts; I have Google'd them, but have come up short.

Thanks in advance,

Shane

 

[GoldDigger]

What I need is a solid reference to these contacts; I have Google'd them, but have come up short.

Thanks in advance,

Shane

If you can find a model number for the relay in question, look at its specifications. If no specific relay is called out, punt.

 

[Aleman]

Like the other poster said, look up specs for your breaker. They are not all labeled the same. Usually you will have an auxillary contact both NO and NC and often there will be an overload contact to signal a fault to a plc etc. And sometimes you will see another auxillary attached to the contactor with another set of contacts.

 

[zog]

"aa" and "bb" do the same as "a" and "b" they just do it faster. Don't recall seeing "ab"

 

[weressl]

Hello folks. I am working through the DC control print for our generator output circuit breakers. Now, I have heard many people say they "know", or "think", but I want absolute, documented information on "a", "b", but especially "aa", "bb", and "ab" contacts, concerning circuit breaker main contact movement and/or position.

I know what a and b are. a should match the main contacts, and b should be opposite them. But what about aa? bb? What do they do exactly?

The tossed around 'knowledge' here about "ab" is they are closed when the main contacts are between open and closed states, which makes sense, since they are used in a breaker failure circuit here.

What I need is a solid reference to these contacts; I have Google'd them, but have come up short.

Thanks in advance,

Shane

http://www.eaton.com/Eaton/Products...rotection/MVVacuum/Generator/index.htm#tabs-2

 

[Sandman1110]

A call to tech support would probably solve your problem......

 

[SG-1]

The documented information you seek is most likely in the breakers instruction manual. The manual may be on line, but we do not know what breaker you have.