There is a cast iron pipe (gray) coming out of the ceiling. If I touch it with the white leg while the black leg of a light bulb is attached to the hot black wire the light will turn on. Then I disconnect everything and test the pipe with a voltage tester and it beeps as I touch the pipe so the voltage tester is accusing power on the pipe but I do not get a shock when I touch it. What is that?
2007-03-30 07:02:36 · 5 answers · asked by Anonymous in Home & Garden ➔ Maintenance & Repairs
Cast iron will conduct electricity and chances are your drain waste vent (DWV) system goes into the ground. To complete an electrical circuit, you need a path to ground, which the pipe that eventually goes into the earth satisfies the electric currents needs and completes the circuit.
If this is the way the light fixture is wired, it needs to be corrected.
2007-03-30 09:40:33 · answer #1 · answered by Ben D 3 · 0⤊ 1⤋
The white wire is the same potential (voltage) as earth ground, connected to the ground block back in the circuit breaker box, along with all the green wires (the safety ground wires). The iron pipe out of the ceiling is safety grounded, so when you touch the white wire, it makes a current connection to ground (through the green wire), and lights the bulb.
You don't get shocked, because it is "grounded". If you touch the black wire you would get a shock. The light bulb "uses" all 120 volts, so by the time the current is on the white wire, it is back to 0 volts, and 0 volts can't shock you.
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2007-03-30 14:10:55 · answer #2 · answered by tlbs101 7 · 0⤊ 2⤋
the ground wire from the electrical panel is attatched to the water pipe where the water line comes into the house this same ground wire is attatched to the netural bar inside the electrical panel. the pipe is acting as a netural wire
you wont get a shock from a netural. you will get a shock from the black if you are toutching the pipe at the same time
you will get schocked by toutching the pipe with one hand and the white that goes to the light with the other hand
it might make the light light by going through your body
2007-04-01 20:10:39 · answer #3 · answered by vincent s 4 · 0⤊ 0⤋
Most likely the pipe is being used as a ground. Have a competent electrician check out the wiring circuits in out your home. If you live in an older house like I do (circa 1881), You will probably have all sorts of electrical additions that are not to code.
2007-03-30 15:11:33 · answer #4 · answered by william g 1 · 0⤊ 0⤋
The white wire and the pipe both act as grounds, meaning that they have identical voltage potiential.
2007-03-30 14:25:53 · answer #5 · answered by MT C 6 · 0⤊ 0⤋