Circiut breakers melting

I recently found that two circiut breakers had melted along the buss in the service panel. I had the entire panel replaced, but the electrican could not give me a good answer as to the cause. Any ideas?

 

Extreme overload or internal failure are about the only things I can think of.

What brand of panel was this?

 

Usually, loose connection to the buss. If this just happens to be A Federal Pacific "Stablok" panel, theyve had design problems which can cause the breakers to melt.If it was a somewhat modern panel, and not attributed to loose connections, that would have to be a SERIOUS overload, over quite a prolonged period of time.

http://www.inspect-ny.com/fpe/fpepanel.htm

 

This was a Challenger panel installed new in 1989

 

What made you look at the breakers in the first place...?

Flickering lights?----If so, what rooms, and on what circuits?
Odor?
Smoke?

This may be fixed, and nothing to worry about any longer, But you paid someone to fix something, and He should at least give you the courteousy of an intelligent answer about where and why you gave him your hard earned cash.

Im guessing you just want the little peace of mind, Which you are entitled to?

 

I hate to disagree, but they didn't pay the electrician for a WAG, but to change out the service. If he speculated incorrectly, and the customer wanted to pursue it with the manufacturer based on his speculation, he could be liable.

 

True..., I didnt think it out that far. But, after spending money on a "REPAIR", I would want some kind of assurance that it wont happen again, at least not for a reasonable amount of time.

I know this is probably beyond electrical, and Into "LAW" , but the customer Paid For a "REPAIR". The service panel change was the electricians recommendation. I too, would be curious as to "What can I do to prevent Repeat Failure".If it was indeed, a Panel failure, fine, conversation over. If on the other hand, Im told that I was wrong for plugging my space heater into the living room outlet, I wouldnt use it anymore.

 

Most common curpit will be:

poor concat on breaker buss tab

wrong breaker in the box [ that is pretty serious issue with it ]

not set in fully [ some breaker will loose the concat over the time ]


up here in my area two or three most common spot i useally find 1] Water heater breaker 2] A/C outdoor compressor 3] electric heat system 4] dryer breaker { not too often but it do show up also }

some case counterfit breaker do show up also that really throw the moneky wrench in the whole work.

Merci,Marc

 

This all started when the heat pump/furnace lost power, initial diagnosis was a lose wire in the thermostat. This ficed the problem for about an hour. Repeat diagnosis was a faulty breaker. This was tested without opening looking inside the panel. Electrician came to replace breaker when melt down was found. The only thing that has changed in the house is a new funace/heat pump in September. I don't recall them getting into the panel at that time and they added andother breaker box at the furnace.

 

Did the new "breaker box" at the furnace have to be wired into the main panel where the breaker failure was located?

 

New box was spliced into the existing power cable from the old furnace to the panel.

 

Sounds like the most likely culprit was the loose connections between the breaker jaws and the busbar. The loose connection will heat up and cause melting over time. Idont agree with a diagnosis of serious prolonged overload as this should have caused the breaker to trip.

 

I would also suspect a loose connection between the breaker and the the bus bar. As other posters have mentioned this can be caused by putting the wrong brand or series of breakers in a panel; or a breaker that is not fully engaged. A loose breaker can be made worse by a humid condition or other corrosive atmosphere.

The loose connection allows a thin layer of oxidation to build up between the contacts which increases the resistance of the connection. This resistance causes heat build-up which increases the rate of oxidation until the heat becomes so much it melts stuff. If the connection is so loose that it causes arcing then the heat builds up very quickly.

 

Correct. I should have worded it a bit differently. "Stressed" instead of overloaded.