Rain Gutters conducting Have 68 volts to ground

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arnettda

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I went on a service call where people were getting shocked when touching the gutters. I put my volt meter between the gutter and a rod I stuck in the ground and found 68 volts to ground. I traced it to a wire that I believe must have gotten a nail in it from the metal lathe they used to but stone on the side of the building. I fished in a new wire but still have 1.5 volts to ground. With the circuit turned off I have .40 volts to ground. The home run comes into a light fixture and splits two ways. One wire feeds the lighting and another wire runs down to the outlets. When I hook up the lighting wire I get just under 1 volt to ground. And then when I hook up the wire for the outlets I get the full 1.5 volts to ground.
Should I be concerned with this 1.5 volts to ground? No where else on the house can I get a voltage reading to ground.( Meter socket, AC units other gutters etc.)
Only the breaker that feeds this area causes the .4 volts to ground go away. So I do not believe some other circuit is causing the problem. And the lighting circuit that cause it to go from .4 volts to just under 1 volt is the brand new wire I ran down to the switch.
Any thoughts would be appreciated. I really do not want this to become 68 volts again down the road.
 
The fact that any circuit lights up the gutter and goes dead when a breaker is off tells me you haven't located every misplaced nail. It's even possible your new cable was nicked by a nail point protruding into a drilled hole through a stud.
 
If you are measuring with a high impedance meter, it’s likely that the small voltages you are reading are simply phantom readings due to capacitive coupling.
 
Craigv said:
The fact that any circuit lights up the gutter and goes dead when a breaker is off tells me you haven't located every misplaced nail. It's even possible your new cable was nicked by a nail point protruding into a drilled hole through a stud.
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My new wire should not be the problem. It is in the garage and I ran a surface conduit from light down the wall and sleeved a 12/3 nm in the conduit and went right into the switch inside the house. Could not run conduit all the way because the switch was offset about a foot. Used a bushing on the conduit and cut a hole on the inside so I could fish the wire.
 
retirede said:
I would kind of expect to read some small voltage from almost any ungrounded metal structure to ground when using a high impedance meter.
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Or grounded. I get 1.7 volts with a high impedance meter from my bonded water pipe to an outdoor faucet to ground about 3 feet away. The voltage drops as I get closer to the pipe, which is buried in the ground.
 
Craigv said:
True, but the fact that there are direct changes in these readings when breakers related to the original problem are cycled is troubling.
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I disagree that it’s troubling. Energizing and deenergizing a circuit can definitely have an influence on capacitively coupled phantom voltages.
 
retirede said:
I disagree that it’s troubling. Energizing and deenergizing a circuit can definitely have an influence on capacitively coupled phantom voltages.
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It's troubling if we don't know for certain that the voltage is caused by capacitance. A continuity test between the gutter and the circuit in question could help in this regard.
 
Craigv said:
It's troubling if we don't know for certain that the voltage is caused by capacitance. A continuity test between the gutter and the circuit in question could help in this regard.
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I would check the voltage with a low impedance meter. I’m betting it reads zero V.
 
what is the Ohm reading gutter to rod?
or put a wire between and measure current

if you are not reading it on other gutters and when you kill the cb it goes away imo you have a nick somewhere
on the meters, etc I would expect 0 since solidly bonded
 
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