Breaker problem to watch for

[Mitchell Andrus]

I had a strange thing happen the other day. The entire house went black. I thought it was a local thing... tree down, etc.... Nope. The 200 amp main breaker tripped. No others had tripped, just the main. That's a bad thing to have happen. A really odd thing.

I turned off the HVAC, workshop, etc and reset the breaker. I checked the amps - 20 or so on one leg, 18 or so on the other but in about five minutes it tripped again.

I removed the cover and felt that the right side of the main was notably hot. I also noticed that one of the 4 screws clamping the right arm to the bus bar was loose (arrow) removing it from the work-force and causing an overload on the part of the right-side breaker still connected.

Tightening the screw did the trick - running full bore and cool as a cucumber. I can however feel a faint vibration in the box... the attic fan is mounted directly over the breaker box and must be the cause, plus a sloppy electrician.

Of all things to have fail, a 5 cent screw.
.

[Rick Huelsbeck]

Only it was my AC unit in the house.

[Dave Wagner]

That happened to me a while back, the main lugs were loose coming in!! It would arc and stuff...had to have an electrician come in and actually upgraded the box to 200A.....good thing!! No more power problems after that....

[Dave Gaul]

I work for a large electric utility. My first job here was a trouble crew supervisor. One of the most common customer problems (other than outages) was flickering lights or partial lights problems... MOST of the time it was a loose connection in the customer's panel or meter base...

Glad you found the problem Mitch and all is good!

[David Helm]

but it was much more major. It wasn't my main breaker that popped, it was the neutral leg at the transformer out at the pole. Just fell out! The lineman said I was lucky we didn't have a fire or other nasty things. The result of the neutral leg falling out of the transformer was a massive voltage surge. Blew out the furnace control board, washer control board, telephone and blew right through the surge protector for the stereo system. The good news is that the power company paid for everything quickly. These days I have a whole house surge protector.