how can i find electric short from room to fuse box?

Question

When I came home last night the wife was setting in the dark in the bedroom. Why are the two hall lights strobing I ask? She did not know, she took a nap and when she woke no power in the room. ok??? but some event had to take place. Maybe you spilled water or the dog thought the cord was a chew toy. While I began to look into this strange event, she tells me she plugged a power strip, with grounding part pulled off, into older multi plug in device. She missed and plugged one side of plug into one receptecle and the other into a different one. Claims nothing happened and lights were still on when she fell asleep when she woke no power.

This is what I know, I reset each breaker with no results. In the hall I have a light switch at each end. If I turn on the first swith only the light nearest the switch comes on. When I turn on other switch both light up but both lights strob. Can not turn lights off in the hall way from either switches. Both blubs are the newer low watt blubs. I am assuming these lights in hall are on the same line as bedroom since this happened at the same time or so I am told. I have unplugged everything in bedroom and tripped each circuit at fuse box. Do not have any old light blubs to see if those might change what I am seeing in hall. I need a little detective insight as to what I should do to find and resolve the problem.

Answer 1

My approach (not an electrician, just a guy with a meter) would be to start by mapping the circuit (find all of the outlets and fixtures that are on it), then unplugging EVERYTHING that's plugged into that circuit and see if that has an effect.

Next up, I'd kill the breaker and open up the switches and take a look. See if there's evidence of burning or arcing, or if one switch feels different than the other. I'd probably disconnect both switches (safely capping all wires), then turn the breaker back on and verify (using a meter) that the voltage is reasonable at all the outlets and other fixtures, and see what happens in the bedroom.

Basically if that tells you nothing, then I'd either start pulling outlets and fixtures off the circuit (kill breaker, remove outlet, capping wires, breaker back on) until I figured out what the heck was wrong, OR I'd just call an electrician.

Answer 2

I had a similar strobing problem with a light fixture -- it seemed to work fine with an incandescent bulb, but a CFL would blink constantly. My first concern was a problem with the wiring in the walls, but it turned out to simply be the light socket. I replaced the socket only (not even the whole fixture) and the CFL worked fine. I suspect it was a slight current leak in the old socket, which looked burned. With an incandescent bulb, it would just dim, a more sensitive CFL would be obviously broken.

You may have a similar problem, but if you're seeing it at multiple fixtures on the same circuit, the culprit is likely at a different point. You'll want to search for the answer by selectively disabling parts of the circuit's wiring and testing there. Things you might consider:

• Disconnect all plugged-in appliances, unscrew all bulbs, and use a portable lamp with a CFL to test electric sockets.
• Trace the path of the wiring, and test with various paths disconnected. For instance, if the circuit goes to a wall outlet and then to an overhead light fixture, first turn off the circuit, disconnect the path from outlet to light, then turn on the circuit and test your plug-in light at the outlet. If it works properly there, then you have a defect in the wiring further on.
• Again with the circuit off, use a multimeter to test for continuity between hot and neutral lines. These should (obviously) not be connected.

If you aren't certain you can do all of this comfortably and safely, please call an electrician. If you do have a current leak, that's the sort of thing that can cause a fire, and should be corrected ASAP.