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circuit breaker overheat

Had two circuit breakers do something odd at home. One tripped, and I assumed somebody had a space heater and a hair dryer on at the same time or something. Then, a breaker for my computer room tripped when I turned on a laser printer. No unusual loads that I haven't done a hundred times before. I unplugged the laser printer, thinking it might have given up the ghost. When I reset the breaker, it was noticeably warm, which seemed odd, as it was not feeding a heavy load. The laser printer and everything else was just fine. It took a couple hours for the breaker to cool. I can't remember for sure if the breaker that tripped earlier had also been warm, but it might have.

So, anyway, it seems these breakers developed poor contact after just staying turned on for several years, and needed the contacts cycled to wipe them clean. I have some other breakers in the shop that are used as shutoffs for various machines, and they never do this, I guess because the contacts are exercised routinely.

Jon

Reply to
Jon Elson
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Can't help with the hot breakers.

Are the ones you are sing to cut off the machines designed to be used as breakers and switches ? Some are and some are not. Then may become weak and trip below he ratings if not over the years.

Reply to
Ralph Mowery

Is this a plug-in breaker, or one that's wired in?

In either case, it seems possible that its connection to the wiring has deteriorated (oxidized, worked loose, etc.) and it might be heating up at that point. If your home has any aluminum wiring, I'd be _very_ concerned about this possibility.

I'd recommend a full re-check, with the mains power entirely disconnected.

Reply to
Dave Platt

Thank you for sharing.

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Reply to
Mr. Man-wai Chang

It is a GE "snap in" breaker in a GE breaker panel (load center). The breakers have fingers that grip a bus bar in the panel, and a screw terminal that holds the wire.

No, NO aluminum wiring! I checked before buying!

The fact that after resetting, the breakers are now running cool tells me the contacts have been cleaned by cycling them, and should be OK for the next 10 years or so.

Jon

Reply to
Jon Elson

I think I'd buy a spare breaker. They always fail in the middle of the night on a weekend. They only cost $5 to $10.

I'd unplug them one at a time, and clean the contacts where they plug into the bussbar on all of them. Also make sure you dont have some device such as a refrigerator, sump pump etc, that may be cycling and/or jammed. Probably would not hurt to remove and inspect every outlet on that circuit to make sure there are no burnt wires or loose connections.

Reply to
oldschool

I'd recommend pulling the breaker that was overheating and replace it with a new one, moving it to an unused nockout spot. Chances are the bus bar has been damaged as well as the breaker at the spot where the hot breaker was put and you can't trust connections at that point on the bus line any more.

Had this happen to a friends breaker box - burnt connection on the breaker also damaged the bus bar at that point. New breaker in a new spot and all was well. It probably hadn't been seated properly and just gradually corroded enough to be noticeable.

John :-#)#

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Reply to
John Robertson

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Maybe you could've taken them to the scrap yard, but since you decided to keep them, how did you cycle them to make their connects better?

Reply to
bruce2bowser

The breaker was in the tripped position, half way between On and Off. I flipped it to Off, and then back to On. I have checked a few times, no sign of heating anymore.

Jon

Reply to
Jon Elson

It is not the breaker per se that was overheating here, it was the breakers contacts to the power bus! I suggest you take that breaker out (safely!!) and check for signs of overheated junction pins on both the breaker wipers and the bus tab.

Had this happen to a friend and it could have been nasty if they hadn't noticed it.

John

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(Please post followups or tech inquiries to the USENET newsgroup) 
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Reply to
John Robertson

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