26 volts with all power off

[uwireme]

Went to a customers home the other day and found a defective GFI after turning off the power I used my pen tester and it was glowing....turned the main off at the meter panel and still glowing. I found 26 volts between the ground wire of where the gfi was and any nail in the sheet rock. This is a wood framed garage with a metal roof and 4160 volt overhead wires running over the garage to another transformer. What could be causing this? EMF?

 

[kwired]

Lift neutral conductor at the service equipment and take measurements again. If this voltage is only on supply neutral conductor call POCO - the problem is somewhere in their system. It is not likely in the meter or service drop unless there is other services coming off same conductors, because you can't have a voltage drop if there is no current flowing. Be a little careful though because if there is current flowing say through your grounding electrode that measured voltage could rise even more when you open the circuit. Maybe clamp the neutral or GEC before lifting the neutral to verify if there is current there.

 

[templdl]

Went to a customers home the other day and found a defective GFI after turning off the power I used my pen tester and it was glowing....turned the main off at the meter panel and still glowing. I found 26 volts between the ground wire of where the gfi was and any nail in the sheet rock. This is a wood framed garage with a metal roof and 4160 volt overhead wires running over the garage to another transformer. What could be causing this? EMF?

Another high impedance digital meter issue? Use an inexpensive analog meter then.

 

[GoldDigger]

Went to a customers home the other day and found a defective GFI after turning off the power I used my pen tester and it was glowing....turned the main off at the meter panel and still glowing. I found 26 volts between the ground wire of where the gfi was and any nail in the sheet rock. This is a wood framed garage with a metal roof and 4160 volt overhead wires running over the garage to another transformer. What could be causing this? EMF?

When you open the disconnect you are not interrupting the service neutral, which remains connected to your local ground wires.
If the POCO neutral is open near the transformer you might see, but probably are not seeing, a phantom voltage at your end of that neutral.
More likely another nearby house is connected to that same transformer neutral and is still sourcing current into your shared ground electrode system. That current is raising the voltage of the ground system relative to remote earth.

If only your local service neutral is open, then there should be no source of current on the grounding system once you open the disconnect and you would not be seeing that 26V reading and the pen tester would not be glowing.