*Shallow end, being shocked when grabbing railing*

[mas985]

Using a ground rod, screwdriver, or attached to the pump bonding?

So using a volt meter, connect one side, with a very long wire, to the pump bonding lug which should also be grounded at this point, and then the other side to a screw driver in the ground. Leave everything setup as when you received the shock to get a baseline measurement.

 

[JamesW]

The basic assumption is that there is probably a live wire somewhere in the ground and that current is going from the live wire and it is being picked up by the ground rod and the bonding grid, both of which are connected to the main neutral.

The ground rod has a wire directly to the neutral bus bar.

The bonding grid acts like a second ground rod because it is buried in the earth and it connects to the neutral by connecting to multiple grounded items and the ground wires go to the main neutral bus bar.

If you can prevent the path for current from the live wire to the neutral, that will increase the voltage difference between the earth and the neutral.

As you get closer to the live wire, the voltage should increase.

 

[mas985]

Again, I think it is important to get a baseline first with the bonding connected as it was when the shock was first received. If you don't get definitive results from that, then start modifying the setup. But I don't think it will be necessary.

 

[JamesW]

The entire pool acts like a giant ground rod.

The amount of surface area and deep exposure will be thousands of times higher than a 6" screwdriver stuck in the dry topsoil.

So, it will pick up the current deep underground and transfer it to the ground wires, which will significantly reduce the voltage gradient.

It's worth a try without disconnecting everything.

However, if the results are inconclusive, you will probably need to improve resolution by disconnecting the ground rod and the bonding grid from the neutral.

 

[mas985]

We have already determined that the pool is energized so yes, it is grounded to earth locally that is energized but that does not mean it is at the same potential as the grounding rod of the house. My supposition is if you were to measure the ground voltage starting at the furthest distance from the house grounding rod, the voltage will be the highest, the closer you move to the house, the lower the voltage until it reaches 0v at the house grounding rod. This will actually increase the voltage gradient with distance away from the house since the house grounding rod is at 0v via the neutral. Removing the grounding rod from neutral will make the ground area surrounding the house at a higher potential closer to what the pool is energized at because nothing is forcing it to a lower potential anymore.

 

[Newdude]

In hard hat speak, If the voltage goes up in a spot, keep going ‘thata way’

 

[Newdude]

Know what we haven’t tried ? Hear me out…..

 

[gamerfan2004]

I did voltage mapping today. I should have a bit of time tomorrow to do this, but I'll post all of my findings and put it on the map. Before I hop off, I was getting 50 - 110mA AC around my house with the ground wire attached to the pump. Ok, I'll post the rest hopefully by tomorrow. Thanks everyone!

 

[mas985]

I am interested to see if there is any significant gradient over the yard. It may be difficult to detect if the source is far away. To show this effect, I did a simple simulation with a set of assumptions:

- Modeled 9 houses' grounding rods and the overhead power line poles grounded to neutral
- All homes modeled grounded to neutral near the intersection of the driveway and house (true for most homes in my neighborhood)
- Voltage source is in the construction zone across the highway (off picture).
- Uniform ground resistance with equipotential lines that are equidistant between source and sinks (pseudo voltage divider)
- All locations are roughly estimated from this photo


The following plot is with the pool bonded at one end (partial bonding). Each light green area is a grounding rod to neutral that forces voltage to 0v, relative to mains neutral. The scale is 0-20v and as you can see, part of the pool is in the area of 1-2v which is close to the measurement.

 

[Newdude]

Idle hands, Schmidle hands !!!! You ROCK Mark.

 

[mas985]

Yeah, too much time on my hands right now. But it didn't take all that long to do either. Excel makes it fairly easy.

 

[JamesW]

Maybe call the people who own and manage the retaining pond and ask them to check if the pond is somehow energized.

Maybe the power wires are going through or near the pond and the water is being energized.

If you feel safe doing it, you can check the pond water to see if there is some sort of higher voltage from the water to your property.

Get a long wire and put some sort of metal weight on the end and drop it in the pond and then run the wire to your property to measure the voltage difference.

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Note: At some point, you are likely to locate an energized source.

So, take all necessary precautions and do not do anything that you are not 100% sure that you can do safely.

If you are unsure in any way, consult with a local professional expert.

Suggested test points at red dots.

 

[Newdude]

I would love to find out what that one lone pole with the buried electric dip services in the middle of seemingly nowhere. (In yellow).

 

[JamesW]

I would love to find out what that one lone pole with the buried electric dip services in the middle of seemingly nowhere. (In yellow).

The pole should have a data plate with some information.

Maybe call the listed utility and ask them to check the area for leaky current.

Maybe go look at all of the nearby poles and equipment and take pictures of all of the data plates so that we can see if there is someone to call.

 

[mas985]

The power company has sniffer trucks that can find stray voltage fairly easily.

 

[mas985]

I would love to find out what that one lone pole with the buried electric dip services in the middle of seemingly nowhere. (In yellow).
View attachment 365228

That is an overhead power line pole possibly high voltage. There is another one at the street corner of the bottom of the picture. In fact, the OPs property is between two sets of these poles. One on the right and one on the left about the same distance apart.

 

[Newdude]

That is an overhead power line pole possibly high voltage. There is another one at the street corner of the bottom of the picture

Exactly. It’s in nowheresville between two houses, seemingly feeding neither of them. The one on the corner could easily go to the intersection controls or street lights. This one is kinda on its own. I’ll drive around again later when I have some time.

 

[mas985]

The power line runs along the highway. The two poles are connected by overhead lines. Here is a zoomed out photo. You can see multiple poles along the highway and barely make out the wires. The construction area on the right is where I placed the voltage source.

 

[JamesW]

Looks like high voltage running all along the street near the pond.

Definitely need to have the power company check it out since it is high voltage.

 

[Newdude]

Disregard the lone pole I was looking at. It feeds the 2 houses there. Those houses looked like overhead service last time making the buried dip suspicious. Maybe Google updated its pics in the meantime. One pole North feeds that lone house and one pole north of that has what appears to be power going to the sump.

So there could be a large pump to drain it when need be.