Understanding Stray Voltage

[Industrial Toys]

I am trying to help a neighbor. The cattle were not drinking from a pail with an approved heater. I gave him another brand new heater, same thing. I measured some voltage, from the ground of the receptacle to some tin on the shack leading into the barn.

I installed a temporary cheater plug, removing the ground and for the time being, the animals drank from the pail.

I noticed there was no ground rod at the barn. The barn is fed underground from a house panel a hundred yards away.

We installed a ten foot ground rod at the barn. I was shocked (pun intended) to still see 7 volts between electrical ground and the tin on the building. That tin is apparently in good contact with Earth Ground.

I understand electrical stuff, and have tried reading up on tingle voltage and stray voltage, but I really don't understand what's happening. Or how to correct it. There are Reactor Filters, which are apparently now seldom used anymore and hence no longer made by Hammond, but I understand that even less.

 

[oldnslo]

Are there any high voltage overhead lines in the area of this barn. I am talking about main transmission lines and not rural transmission lines. Reason for asking is that was a problem for Dairy farms in Minnesota after they ran a new high voltage transmission line through the area. If I recall correctly is was in the 400 KVA range.

I do not recall what all had to be done to eliminate the stray voltage problems.

 

[Industrial Toys]

Thanks. No, just the 3800 single phase coming in and it's as far away from the barn as it could be.

 

[oosik]

Hmmm - many years ago a horse I had would not drink out of the water trough. The trough was a 55 gallon plastic barrel - on its side and cut open. Had a tank heater in the barrel. Everything was grounded according to code. Horse would bend down to drink - lips would start quivering and she would back off. Took the tank heater out - still no joy.

Soooo........tank heater back in water trough - 2x daily - scoop water out of trough with plastic 5 gallon pail - horse would gratefully drink out of 5 gallon pail. At the time - thought horse was Norwegian like me and just stubborn. Maybe it had something to do with water trough being directly under high voltage lines bringing power into house and out buildings.

Maybe horse WAS Norwegian, like me, and just stubborn - - who knows.

 

[Industrial Toys]

When this house was built in the early 70s, you would get zapped touching the shower controls in the basement, on cement shower. A volt meter between metal knobs and drain would confirm this.

Had an army of Ontario Hydro inspectors and Electricians in. Everything to code, just live with it! I always used my palms and made my adjustments quickly. I was contemplating putting in plastic shower knobs.

Anyway, it SEEMS that when I replaced the water heater years later, the problem went away.

I never really thought about it, but reading up on this stuff I learned that concrete is a better conductor than soil.

 

[CADplans]

My BIL had that at his shop,,,
it shocked everyone for years,, whenever the soil got dry,,,

I went hunting it, it turned out to be a loose connection of the ground at the box that fed the shop, 150 yards away,,,

Two turns of a screwdriver, the ground/shock problem was eliminated.

That was all copper, as the shop was old,,,
new stuff, with aluminum wire, can easily have a loose/corroded connection,,,

 

[Industrial Toys]

I had driven the ground rod with a hydraulic breaker and made quite a hole, hitting bedrock with about a foot to go. So I thought, maybe the ground rod was making poor earth contact. First I tamped dirt into the hole, with no improvement and then poured a couple of pails of (hard) water. Not one volt difference from the 7 volts, electrical ground to the tin!

For what it's worth, he does have a solar microfit installation on a shed close to the house.

 

[CADplans]

I had driven the ground rod with a hydraulic breaker and made quite a hole, hitting bedrock with about a foot to go. So I thought, maybe the ground rod was making poor earth contact. First I tamped dirt into the hole, with no improvement and then poured a couple of pails of water. Not one volt difference from the 7 volts, electrical ground to the tin!

For what it's worth, he does have a solar microfit installation.

The ground rod, IMHO, should not make a difference,, it is there more for a safety/emergency purpose,,,

The ground wire(s) from the box feeding the outlet being used should be grounding the circuit.

Disconnect the ground rod (temporarily),,, the disconnection should make no difference in the voltage measured.

Measure the voltage at the other end of the ground wire,,,

 

[JPRambo]

Is the feed to the barn 240 volts? Does the feed to the barn have four wires? Is the trough heater 120 volt or 240 volt?

 

[RNeumann]

You need to go back to the panel and start there with your meter. Systematically isolate each wire to see where the voltage is coming from. A circuit, the main/service to the barn etc. If the barn has multiple circuits they should all be off to start.
It’s likely something got pinched or chewed in the barn. Second is an underground line. Etc etc.