"John Grabowski" wrote in message
...

"RBM" wrote in message
...
A customer called with an intermittent electrical problem: The electric
range and refrigerator on occasion stop working, then start working for no
apparent reason.
It's obvious that one of the hot legs is opening, as that would be the
only common denominator between a 120 volt refrigerator circuit, and a
240 volt range circuit. The customer was also unaware of a multitude of
other circuits that were also dead. Usually when I get these calls, I
start with the connections in the most hostile environment, 1) The
overhead service connections, 2) The outdoor meter socket, then check the
main circuit breaker. In this case the culprit was the main circuit
breaker, which by all outward appearance, looks fine. There was antiox
paste on the conductor connections, no hissing or crackling sounds, and
the breaker was cool to the touch. Upon removing the breaker, the problem
became clear. A bad connection (factory) between one pole of the breaker
and the panel buss, over time caused overheating and annealing of both
the panel buss and the copper contact of the breaker. Pictures to follow:
http://i17.photobucket.com/albums/b9...ldamage006.jpg

http://i17.photobucket.com/albums/b9...ldamage008.jpg

http://i17.photobucket.com/albums/b9...ldamage003.jpg

http://i17.photobucket.com/albums/b9...ldamage005.jpg



Thanks for posting Roy. Did you have to change the load center?

Yes, that one section of buss was shot. My picture doesn't show how
discolored it is was where the breaker connected to it. This is the 3rd
Murray main breaker go bad this way that I've seen in this past year. The
other two showed up in time to save the buss.