Test equipment to find broken electrical wires in wall (due to raccoons chewing wires)?

Question

We noticed an electrical burning smell in one bathroom in our house yesterday and immediately called an electrician to check out the wiring. He checked all of the sockets and fixtures in the bathroom and all the rooms near the bath. Unfortunately found nothing. He also crawled through the attics looking for wire damage and checked the HVAC system.... again nothing.

We're really concerned as we recently evicted a family of raccoons from one of the attics and are afraid that they might have chewed the wires in the walls. The house has many mechanical passageways and a truss floor system for the upstairs so the critters could have traveled anywhere.

Does anyone know of testing equipment or a method to test for damaged wiring in the walls?

Thanks!

Answer 1

Your local electric supply house has a device for just this sort of thing.

It ain't cheap, but it is cheaper than hiring an electrician to rip out walls, ceilings, etc to find gnaw marks on wires.

BTW, that's cheaper than replacing or repairing your home after a fire.

The device I am thinking of attaches to the wires at the breaker panel and emits a high freq signal. Trace the signal with a portable reciever and when you lose signal, backtrack about a foot and you'll fine the end of the wire.

MAKE SURE you turn off the main breaker before attempting this.  

Answer 2

I tend to agree w/ bob b

Answer 3

There is some equipment that can trace a certain conductor through sheet rock walls. It takes special training and careful use to operate safely.  Most times when you smell this aroma, it from a conductor arcing and the insulation melting. Since you have brought in one electrician already, I can only suggest that the circuits be secured and each junction box or light fixture or switch be inspected.   A temperature indicator may give some hints where the problem is located. This unit works best when the temperature in the area is cold. The common use of this item is for an energy audit by insulation and heating and cooling contractors.  It is expensive in many cases.  Try to use your nose and be careful.  Good luck.

Answer 4

There are wire tracing devices available starting at around $200 for one capable of reading several inches deep in walls and floors.  If the wires are still connected somewhat, an electrical test may not find the problem.

Since you smell smoke, a weak wire may be overheating in the wall and you should have better luck finding it with a rentable thermal imaging scanner/camera.  A bigger/better electrical contractor should have one for finding just that kind of problem.

Answer 5

Unless the damage is causing a short circuit (two bare wires touching) or an open circuit (a break in one of the conductors), finding any damage will be extremely difficult to do without actually inspecting the wires to check the insulation. To most conventional test equipment, a pair of conductors, with or without insulation on them, will appear to have identical characteristics.