Under Voltage Release or Shunt Trip

[danilo]

Gentlemen,

For earth leakage protection,which between these devices are best used to trip the breaker?

Regards,
Danilo

 

[Jraef]

I don't know if the application matters or not, but a UV trip can be a nuisance because it trips every time there is a power failure, requiring that you manually reset the breaker. Consider the implications of that.

 

[danilo]

I don't know if the application matters or not, but a UV trip can be a nuisance because it trips every time there is a power failure, requiring that you manually reset the breaker. Consider the implications of that.

Thanks Jraef, actually using UV is what i prefer for earth leakage protection to be on a "fail safe "mode but i worry about its coil because its always energized.

 

[ATSman]

Gentlemen,

For earth leakage protection,which between these devices are best used to trip the breaker?

Regards,
Danilo

I have never seen a UV device used in a GF protection scheme. A shunt trip is used in this application if the GF relay is external to the breaker. If the GF protection is built into the breaker trip unit then a separate trip actuator trips the breaker.
A UV device is used to protect motor or other voltage sensitive loads by preventing single-phasing which can burn up the load. They normally have to be manually reset but I have seen cases where it is done remotely.

 

[danilo]

I have never seen a UV device used in a GF protection scheme. A shunt trip is used in this application if the GF relay is external to the breaker. If the GF protection is built into the breaker trip unit then a separate trip actuator trips the breaker.
A UV device is used to protect motor or other voltage sensitive loads by preventing single-phasing which can burn up the load. They normally have to be manually reset but I have seen cases where it is done remotely.

Hi Tony, yes it can be used in that protection scheme with an Earth Leakage Relay of course. A relay's NO contact is in series with UV coil.This contact closes when relay is energized and opens when de-energized or under fault condition,thus trips the CB.

 

[ATSman]

Hi Tony, yes it can be used in that protection scheme with an Earth Leakage Relay of course. A relay's NO contact is in series with UV coil.This contact closes when relay is energized and opens when de-energized or under fault condition,thus trips the CB.

Danilo, I understand that it can work that way. What I meant was that it was not the conventional way of wiring the circuit.