Adjusting CB settings while in service

[farmaped]

Any issue with adjusting the settings on a LVPCB trip unit while in service?
In particular, Amptector 1A on a DB-50? (Or any CB-Trip Unit combo for that matter)?
I see no issues, just want to confirm after I got questioned. This is, of course, assuming the new setting(s) passes all other applicable scrutiny.
Thanks

 

[jim dungar]

It depends on the breaker. There times as you switch from one setting to another the breaker is confused as to which one to use, so it defaults to its minimum setting.

 

[zog]

Any issue with adjusting the settings on a LVPCB trip unit while in service?
In particular, Amptector 1A on a DB-50? (Or any CB-Trip Unit combo for that matter)?
I see no issues, just want to confirm after I got questioned. This is, of course, assuming the new setting(s) passes all other applicable scrutiny.
Thanks

Jim said it right, sometimes they default to the min setting when changing, if your load is less than that you should have an issue. Why are you changing them? A one time things or are you doing the maintenence setting thing for arc flash reduction?

 

[farmaped]

Interesting. So, in the case of the Amptector with the dials, while I am physically adjusting the setting, it will revert to the minimum. I guess on a digital unit it would be the time period from hitting "enter" or "save" until it registers.
I've never reduced soley for arc flash reduction during energized work, but understand others do.
In this particular case, I am just moving it back to the original setting because someone got antsy after an arc flash survey to minimize breaker settings. Unbeknown was the additional load that was temporarily disconnected during the survey, and is now back on line (except when it is tripping the breaker).
Thanks again.

 

[zog]

Interesting. So, in the case of the Amptector with the dials, while I am physically adjusting the setting, it will revert to the minimum. I guess on a digital unit it would be the time period from hitting "enter" or "save" until it registers.
I've never reduced soley for arc flash reduction during energized work, but understand others do.
In this particular case, I am just moving it back to the original setting because someone got antsy after an arc flash survey to minimize breaker settings. Unbeknown was the additional load that was temporarily disconnected during the survey, and is now back on line (except when it is tripping the breaker).
Thanks again.

I dont think it will on an amptector 1A, but I cant promise it wont. I hope you adjusted your arc flash survey, labels, and required PPE after changing that setting.

 

[farmaped]

Usually ture, but not in this case. Only changing the LTPU, and nothings labelled anyway.

 

[zog]

Usually ture, but not in this case. Only changing the LTPU, and nothings labelled anyway.

Ha! If LTPU affects your arc flash study you would have a big problem. The ones that usually get you with defaulting to the min are the STII and STIII's, Digitrips, etc, the ones with the little "Click" between set points. Amptectors are too old for any of that fancy logic and fail safe stuff.