View Full Version : Metal conduit conducting electricity
mistapony
Apr 18, 2014, 03:11 PM
I have an old flexible conduit that I want to put an outlet on. There are two wires inside with no ground, kind of paper wrapped. I turned off the circuit breaker and attached an outlet. The outlet doesent seem to work. I tried switching wires and still nothing. I then had a light socket to test the wiring and for some reason my light only turns on when I touch one of the wires and the actual metal conduit? Im not sure what to do to make this work?
ma0641
Apr 18, 2014, 07:46 PM
Was there electricity through the wires before you installed the outlet? Sounds like the neutral is missing. The conduit (BX)is grounded so it is conducting 120 back to the house ground. DO NOT leave in this condition as you can get shocked. What you see is typical, should be 2 wires, a hot and a neutral, insulated from the conduit and the conduit ground. Older BX had paper insulation so I am guessing we are talking an older house.
mistapony
Apr 18, 2014, 09:23 PM
Thanks yes this house was built in 54. Im not sure what condition this wire was in since it used to be connected directly to an old sprinkler system that is not in use anymore. I guess the neutral wire is either not spliced correctly somewhere but I'm not sure where I would find that. Guess I'll need an electrician for this one.
ma0641
Apr 19, 2014, 07:16 AM
Go to any outlet on the circuit and see if the neutral is loose or disconnected before it goes to the next outlet. Look at the connection where the sprinkler was connected. With BX you would have metal boxes. Do you have 2 or 3 prong outlets? Some city and industrial codes still require BX, for physical protection, but it is pretty much gone in house circuits.
donf
Apr 19, 2014, 07:53 AM
Before you do anything else, shut the breaker off to this cable. This is a potentially deadly condition. If anyone handles this cable and manages to bridge between the hot source and the outer shell, then they could get serious hurt.
First, please obtain a multimeter for testing, not a light. After you have the meter, turn the breaker back on and carefully make some tests. If you have clean leather gloves wear them.
Then, using your new multimeter, place the red probe on the Black conductor and touch the black probe to the other conductor. What is the voltage you get?
If it is 120 (+/-) then the connection from the circuit breaker to the receptacle is correct.
If you do not get 120 V, then move the black probe to the metal skin of the BX and give us the Voltage.
Now move the Red probe to the second wire and measure the voltage. What is the voltage you get? If it is 120 (+/-) volts, then I suspect hat there is a fault condition within the BX conduit.
Either replace the entire BX cable with new BX (this may be require within your local area) or if the receptacle is in a dry location, you may be able to replace the BX with NM-B cable. If the circuit is 15 Amp, then use 14/2 with ground. If the circuit is 20 amp, then use 12/2 with ground.