Sam wrote:

hi there,

i have an old PC that after I use I have a habit of unplugging from
the wall. The last few times though when i unplug the turned off PC a
Circuit breaker is tripping. why could removal of a plug of a switched
off device cause this?

Sam

Could be:

a. A bad power cord fith failed insulation where the cord enters the plug
producing a short across the line occuring only when you grab the plug to
pull it out. (You're not pulling the plug out by the cord, are you?)

b. If the breaker happens to be a GFI type; If you're removing the plug
"slowly" you might be breaking one side of the hot/neutral pair before the
other side for long enough to cause tripping of the GFI. They can be funny
about things like that.

c. As the others have already said, the outlet might be loose and moving
around inside it's box, causing something to short out in there.

Try plugging a different piece of equipment into that socket, with a
similar type of (Polarized/grounding) plug, and wiggle and twist the plug
while removing it. If the breaker blows, make sure it stays off (no one
flips it on for you without warning), take off the outlet plate, and look
for the problem inside.

Good luck, and let us know what you find,

Jeff


--
Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can keep smiling when things go wrong, you've thought of someone
to place the blame on."