Jeff Wisnia ) said...

The breaker "protects" the wiring and devices to the best of its
ability, ....

Breakers are there to limit heating caused by overcurrents and by so
doing prevent fires. Thus, they only indirectly "protect" humans.

Basically, yes.

Many people think electric circuits work using the "theoretical model"
taught in school science class (i.e.: perfect conductors with zero
resistance, voltage sources with no internal impedance, etc).

To that, this thinking extends to the idea that a circuit breaker trips
at the instant the current exceeds its rating.

In actual fact, a circuit breaker is a thermal device that takes time
to react to current in excess of its rating. As short as that time is to
us humans, durinig that time there is the entire generating capacity of
the grid you get your power from behind that current (less the impedance
of the transmission network). Suffice it to say, in that short instant
the current can reach a VERY high level. Many panels and switchgear will
have a peak current rating of 10,000 amps or higher for this reason.

I stand by what I wrote, the OPs "wiring" wouldn't have much chance of
being damaged because the breaker (which popped) would have protected them.

I agree - the "wiring" wouldn't have much chance of being damaged.

However, some switch contact where the short occurred probably now has a
nice little dimple on it where the short lived short circuit current spike
vapourized it. Not likely to effect its future operation, unless you
continue to repeat the same action a number of times.

--
Calvin Henry-Cotnam
"I really think Canada should get over to Iraq as quickly as possible"
- Paul Martin - April 30, 2003
-------------------------------------------------------------------------
NOTE: if replying by email, remove "remove." and ".invalid"

*** Free account sponsored by SecureIX.com ***
*** Encrypt your Internet usage with a free VPN account from http://www.SecureIX.com ***