What would cause this?

Bottom of hot bus bars are tarnished. I am not really sure this is from overheating. Any thoughts?

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I would think it is air sneaking in past the cover and some sort of fumes over the years have stained the buss. No big deal.
Roy Cooke sr

It could have been over heating in the past, but would not be now. There is nothing attached there. I see no problems, no need for correction…

Why is the breaker tripped?

Looks like heat caused that.

Take a piece of plated metal and heat it up and you will see a multi-color pattern result like that… :wink:

What Patrick said. That is exactly what overheated metal looks like.

Ben, I dont know why the breaker was tripped. There was actually two breakers tripped and some with pieces of tape on them. No idea why it was like that. Just saw that both parts of the bus were tarnished/ overheated.

It does have the appearance of overheating in the past. I am sure you also reported the tripped and taped breakers, but the markings, I personally would not.

Looks to me like a double pole breaker overheated and was removed. I would report it. I also would recommend that no breakers be install in these 2 slots.

That’s what I was about to post when I read your post. I agree with your assessment. It is also possible that the overloaded 2-pole breaker that was removed and move to the location of the now tripped breaker. The load on the tripped breaker should be measured but that’s beyond the scope of work for most HIs eventhough I do carry an amp clamp with me. JMHO

If the cover shows any missing spaces where identified closures were installed, I too would identify the “metal discoloration” as being caused by an overcurrent condition “OVERLOAD” and would point this out as something that should be reviewed by a qualified and licensed electrician.

I saw this same “fatigue” once when the renewable link fuses were tripled in a 3 phase 200 ampere disconnecting means that was constantly over heating.

If I am permitted I can post this image on another site frequented by licensed electricians.


In your opinion should this be reveiwed by an electrician regardless if those positions are never going to be used? Or statement like “The bottom four breaker positions should not be used untill reviewed by a qualified and licensed electrician.”

If the client has no intention of ever using those positions and has been informed that if they are to be used in the future then at that point get it checked out, do you see a problem?

Joe the Cover has no missing tabs. Although at the time of inspection the breaker above the scorch was tripped off. Maybe just coincidence.

And what would be their recommendation???

THat there is evidence of possible overheating and that is it. ?

As an electrical contactor my advice to the home owner would be to not use those spaces and that if in the future they need the additional space in the panel to replace the entire panel.

Thank you everyone for your replies.


I agree with Joe.

What about the tripped breaker?
Bottom right.