auxilliary contacts in relays and in vcb's

[supercore]

what function does the auxilliary contacts in vcb and relays serve?
what's the need for auxilliary relays??

 

[Darkwood]

Excuse my ignorance what is VCB?

 

[Guest123]

VCB - Vacuum Circuit Breaker.

Also auxiliary contacts can be used for a number of things i.e overload protection, earth fault protection, voltage spikes etc etc.

 

[Darkwood]

Been a while since i came across one of those, but to answer the question aux' relays perform limitless no' of functions tailored to each job, their are ideal for running different control circuits through which may have seperate voltages or fusing, they can among many uses bring indicators on if device trips, or stop certain controls activating unless contactor is energised etc etc.......

 

[sparks1234]

I fitted some replacement relays the other day controlling some lighting. I called the wholesaler and they said they only had 3 pole isolators but they are actually 3 pole plus auxillary contacts, so 4 pole, why they call them that i have no idea, just confuses things

 

[benji]

4 pole relay-all poles can carry same current ,an aux pole might not be rated the same as the other poles
and could be n/c or n/o

yours benji

 

[thepurple1]

If the circuit breaker is powering something critical then you can use the spare contacts to indicate that the power had tripped, e.g in to a BMS system