- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
We got a call from the fire department about a double wide that had the entire aluminum siding energized. We were called out because a nail driven thru a shroud for the electric heat pack (all in one unit) had arced and caused a small fire.
We were sure we would find a nail that was driven into a wire?nope. No wire just a nail into the metal shroud that was attached to the siding?we were told. We open the electric heat pack unit that sat right there and found a mouse that was shorted from one terminal to ground. The mouse energized the frame which in turn energized the shroud and the siding. Removed the mouse and the voltage disappeared from the siding. Not sure how the nail caused this problem but the nail must have been touching a ground and arcing across it. This is info from the FD as the siding was ripped off when we got there.
We also found an arcing neutral at the main disconnect on the pole- lot of corrosion and a mess?Of course he didn?t want to pay for more than he had to so we cleared the mouse short- insurance money and replaced the neutral bar in the disconnect?his cost-- The whole place needed work but that is all we did.
I guess the resistance in the mouse was too much to trip the breaker but my understanding was there were no wires near where the culprit nail was that had caused the fire. The nail, I assume must have had some contact with ground--Yes?
We were sure we would find a nail that was driven into a wire?nope. No wire just a nail into the metal shroud that was attached to the siding?we were told. We open the electric heat pack unit that sat right there and found a mouse that was shorted from one terminal to ground. The mouse energized the frame which in turn energized the shroud and the siding. Removed the mouse and the voltage disappeared from the siding. Not sure how the nail caused this problem but the nail must have been touching a ground and arcing across it. This is info from the FD as the siding was ripped off when we got there.
We also found an arcing neutral at the main disconnect on the pole- lot of corrosion and a mess?Of course he didn?t want to pay for more than he had to so we cleared the mouse short- insurance money and replaced the neutral bar in the disconnect?his cost-- The whole place needed work but that is all we did.
I guess the resistance in the mouse was too much to trip the breaker but my understanding was there were no wires near where the culprit nail was that had caused the fire. The nail, I assume must have had some contact with ground--Yes?