I was replacing a failed breaker last week and noticed a gray film on
several of the wires in my entrance panel. This film seemed to be on
the feeds from the meter so I pulled the meter. One of the load side
aluminum lugs had melted and the aluminum wire connecting the main
breaker to the meter base had been "welded" in place. Not a pretty
sight since the only protection I'm aware of is a 10 amp fuse in the
primary (13 KV) side of the power company's transformer. Burning up an
underground line from the transformer to my meter base would not have
The moral here is to look carefully at conditions in the panel when
working there. I had no symptoms, no flickering lights and no variation
in voltage with load but still had an unstable situation.
I now have a new meter base and copper wire.