"mndean" wrote in message
oups.com...
Hi Everyone,.
It seems whenever the temperature gets over 100 degrees or so, a
particular breaker in my house will trip if even a slight load is put
on it. The breaker box is being directly hit by the sun in the
afternoons, and it seems that if I attempt to cool the box, this cures
the problem temporarily. The problem will go away as soon as the sun is
low enough so the box is in shade. Is this a faulty breaker? I'm not an
electrician, so how much would it be $-wise for an electrician to come
out and fix this? Thanks for any help you could give me in this!

--
mndean


When you have a short circuit, a bi-metal link inside the breaker heats up
and then deforms thus flipping the switch off.

Given that most breakers use this thermal mode to trip, excessive heat in
the enclosure can derate the breakers trip point but it should not be as
extreme as you describe. That breaker is obviously defective. The ambient
temp rating of the breaker box is at least 125F.