Meter main tripping

[Therealcrt]

A family friend of mine who lives in a townhouse called me over because they are 150 amp meter main breaker has tripped for the second time in three days. The first time was Saturday. The second time was tonight. He reset it both times but tonight when he tried to reset it, it would not go on, so he called me over I looked inside the panel in the garage, which is a main lug 100 amp panel. All breakers were on. I turned on all appliances, ran everything I could, and did an amp clamp on both legs it’s single phase by the way with all appliances running, and lights on each phase was drawing around 40 to 50 A when I went outside to the meter bank I took the cover off and tested those wires as well. I got the same result the voltage was correct as well. 120 240 after 10 minutes the meter main tripped so I checked for loose connection at the main breaker. Everything was tight but one leg was really really hot to touch The other was not. my conclusion is a bad 150 amp main breaker. I did all the troubleshooting I thought was necessary is my conclusion, correct or what else could it be?

 

[hillbilly1]

Probably, but may also be a burnt stab where the breaker plugs on if that type. Replacing the breaker may not be the only thing. Hopefully, the installer just overtorqued the lug, and damaged the breaker.

 

[Therealcrt]

Probably, but may also be a burnt stab where the breaker plugs on if that type. Replacing the breaker may not be the only thing. Hopefully, the installer just overtorqued the lug, and damaged the breaker.

I won’t know until I get the utility company to pull the meter and I go to take off the breaker to find out

 

[jaggedben]

150A breaker protecting a 100A panel?

Not the cause of the problem but maybe you should address that.

Also if it would not go back on, what did you do to get it to go back on? Reset it again? If it resets some of the time but not all of the time, then I think that probably does point to the breaker.

 

[ptonsparky]

Doing a FOP across the breaker and connections will pin point a bad one every time. $50 thermal scanners are available about everywhere.
I would agree with bad breaker.

 

[Therealcrt]

150A breaker protecting a 100A panel?

Not the cause of the problem but maybe you should address that.

Also if it would not go back on, what did you do to get it to go back on? Reset it again? If it resets some of the time but not all of the time, then I think that probably does point to the breaker.

Sorry for the confusion it was a typo Its 150a breaker serving a panel so yes it's a 150a panel. Yes when I was there it was able to reset. But it tripped again like I said when I was there and when I went to reset it that time it would not reset just kept going back to the tripped position. I told my customer it’s a bad breaker and to contact their HOA