Main bus bar discoloration. What do you think?

I can’t remember seeing discoloration like this before on the ,main bus bar. Am I getting too excited or is that evidence of overheating perhaps?

I would call it out for review by an electrician, looks like overheating, maybe something is loose, who knows. Do you have a pic of entire panel? Is it rated for 200amps?

I agree with Simon.

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Had something similar at my house. The weld on the lug had failed, resulting in a loose connection.

Looks like you’ve got some melting plastic


How did you learn about the issue?

It tripped the main breaker one Saturday morning. I thought it was a power failure, but my neighbor had power. I reset the main and all was cool for about 20 minutes. Then I called the POCO since I live adjacent to a power plant and sub-station. They were there in 10 minutes and tested the line in and ground and all was good. That’s when I took the dead front off and noticed the discoloration and scorched plastic. The POCO guy saw that and said I think we need to pull your meter until that gets replaced. My electrician had the buss replaced several hours later.

Its 200 amp. I’ll give you a pic of the whole panel. I didn’t see any melted plastic but I will call it out now. Thanks everyone.

Sorry. I think I doubled up there on one of the pics.

I don’t think it’s likely to be heat damage (I don’t see corresponding damage to materials that are more heat sensitive than the metal bus), HOWEVER, I would recommend that it be checked, just as others have recommended because it may be.

I would have checked with an IR imager or at least my IR thermometer to see if there was a thermal exception at the time of the inspection.

I have seen something similar on GE panels. When checked everything was tight and there were no visible signs of heat damaging either the conductors or surround plastic materials. Could just be a thing with the metal used by GE in their panels. As Chuck stated an IR image would help.

As others have said an IR image would help but it looks like bad plating to me. Many of the components GE uses now come from Mexico and Mexico has issues with plating quality.

I see three instances where terminal screws on L1 are different than L2.

I would not turn up the juice to test, but why didn’t you measure temps?

Good call. Since the cause of the discoloration is unknown, examination is a reasonable recommendation.

I should have measured temps. It was one of those things where it looked weird when I had the cover off and then when I got home and looked at my pictures, I thought, that looks really weird so I’m just glad I called it. Just a bit wiser every day. Just a bit.

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Good catch!
Your not required to put anything into an electrical panel anyway. Observe and report (regardless when you observed it).