Arc Flash Mitigation at LV Switchboard

[philly]

I was interested from hearing from some of the Arc Flash experts here what their
thoughts are for installing an arc flash relay (current and light sensing) for arc flash mitigation on a LV switchboard? Is it practical to install CT’s in incoming section with remote trip to upstream breaker? I would assume these CT’s would need to be installed on the line side of the main breaker on the incoming cables ahead of the breaker in order to mitigate hazard on line side of main breaker.

With switchboard AF mitigation the solution I’ve seen most often is to implement a maintenance mode in upstream breaker to reduce AF at downstream switchboard.

 

[jim dungar]

I was interested from hearing from some of the Arc Flash experts here what their
thoughts are for installing an arc flash relay (current and light sensing) for arc flash mitigation on a LV switchboard? Is it practical to install CT’s in incoming section with remote trip to upstream breaker? I would assume these CT’s would need to be installed on the line side of the main breaker on the incoming cables ahead of the breaker in order to mitigate hazard on line side of main breaker.

With switchboard AF mitigation the solution I’ve seen most often is to implement a maintenance mode in upstream breaker to reduce AF at downstream switchboard.

I have done both of these methods, several times. I have no preference, each system can be different.

 

[drktmplr12]

the questions for a shunt trip is: can the remote trip function quickly enough and how long will it take breaker to trip and reduce the energy? this would need to be calculated.

the maintenance switch provides a somewhat false sense of security, as it is only active when engaged. the photocells and CT's will always be active.