Stray Voltages??

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We have installed a new 200 amp service in my son's shop.
While I was wiring up some of the outlet boxes(metal), I noticed a slight 'tingle'. The floor is concrete, 10" thick and a bit damp. When I went back to the service entrance, I measured between the earth ground (2-8' copper ground rods, 10 feet apart) and the concrete floor and read a voltage of 1.995 volts AC. I could not read nor detect any current flow.
My question is this- Is this a potential hazard and what would either cause this or what would I need to do to remedy this situation? The building is a steel building and I have grounded the frame of the building. Will bonding the frame of the building to the concrete floor clear this problem? I have no way of getting to the reinforcing mesh without a lot of work.
Thanks,,,,,,
BTW- everything is run in 3/4 EMT
 

ptonsparky

Senior Member
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
Electrical Contractor
I am hoping this is not a new building, because a Ufer would have been a good start for preventing this. Single phase, 3 wire, or 4 wire? Check for loose connections on the neutral all the way back to the POCO transformer. Undersized neutrals or excessive neutral voltage drop is a problem. Balance the load as much as possible. You could have a well motor going to ground. Make sure you do not have any neutral bonds other than at the buiding service entrance. While monitoring the voltage shut the loads off one at a time until you notice a change, make note of which load and invdstigate it for faults. Could be your neighbor, could be the POCO. Is the neutral bonded at the service entrance & are the rods bonded to the neutral?

If you feel it, it is a potential hazard, your pun, not mine. Good luck.
 
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