Sub panel main tripping?

Hello and Happy Holiday’s everyone. I am going to check my neighbor’s sub panel main breaker that is located in the main panel in the garage tomorrow. It has started to trip on several occasions and shut’s down the entire basement and his office. I told him it was probably loose or a bad breaker. I also wanted to test the Temperature of the breaker if it loose to see if it’s overheating. I don’t normally do this, so what temp would I be looking for on a 100 amp sub disconnect?? any help would be greatly appreciated!!!


Have you looked at the load? It may be a real O/C trip.

Translated…It may be a real short in the system that is causing this.

Hi Chuck, hope all is good in southern Michigan.

did they put up any xmas lights this year?

did the issue begin after they did?

bad or loose breaker possible…i’d investigate overload issues first, though.

temp of the breaker will depend on many factors…manufacturer, ambient temp, etc…

Well, that was confusing.

You are going to check the disconnect or OCPD for the load side panel? The disconnect is located in the service equipment?

As others mentioned, it’s likely there’s actually an over-load or short somewhere. Checking the temp of the breaker doesn’t tell you whether it’s a poor connection or an over-loaded circuit - it will only tell you the temperature.

I don’t know why you’d waste your time doing such a thing. Have him call a licensed electrician.