Reduce incident energy by lowering instantaneous trip setting

I intrepret NFPA 70E110.9(D) to allow me to reduce the instantaneous trip value of a circuit breaker, as done in device coordination, to also reduce incident energy.

What keeps me from reducing to a minimum value (with calculations done) to a minimum when performing work and then resetting when done.

There are add on devices now on the market that do just that.

We generally refer to those as maintenance settings for the specific purpose you are asking about. Depending on the breaker and associated overcurrent protection you have, it might have an alt settings available. If so you can use the front panel or an external switch to enable them once configured. You could lower your pickup, time delay, and inst. if necessary. And you are correct about the other devices available if your relay does not allow it.

You could also look at the entire facility (if practical) to see if you could modify the settings permanently as they may be elevated now just to insure against nuisance tripping without regard to arc flash issues.

Don't usually like the idea of "dialing it down" by hand since it may not get back to the correct setting after the work is done.

There are other posts here about this very issue if you can find them.

Hope it helps.

Thanks for the reply

Good points. I would not suggest this to our guys just seems too easy and too easy to make the wrong assumptions once the setting is made.