ECN Forum Forums General Topics of the Trade General Discussion Area Stray Voltage

I think that if you really do everything in 680.26 you will create an equipotential plane that will prevent a problem in the pool. I believe the problem is when you do not get something bonded. In the case of an inground concrete pool with a bonded deck it may end up being the best ground electrode on the street.

Harold:
Just noticed that JCP&L is doing line work in my area. Looks like new primary HV line work prep.
As to specifics, I'm reaching out to the guys in the area to see if any info available, other than the stuff in the papers.

Greg:
The pools that were involved probably are 'older', and don't have 680.26 grids.

I think the only thing that has changed in decades in 680.25 is bonding the deck. That still was happening here before the change if it was concrete. The pavers was the new thing, although pavers are the most common pool deck in new construction. If your back fill isn't properly compacted the concrete deck will fail. With pavers they just pull them up, put in more dirt and lay them back down.

Greg,

Somewhere I've read that you don't want ground rods by pools because you don't want to attract electricity. Wouldn't that be sort-a the same thing with the grid under the pavers? Granted I realize by bonding everything together, you have the same potential. Doesn't the pool with the rebar (or metal side) kinda act like a "Farrady Cage"? (sp?) So if there was stray voltage, it would get sent down the #8 bonding wire.

The concrete pool is a ufer, no matter what people rationalize. It is a ground rod. As soon as you realize this and bond everything to it six ways from sunday you have created that equipotential plane 680 talks about. You, the pool, the water, the deck and all the equipment might spike thousands of volts in a nearby lightning strike but you are a bird on a wire (or a helicopter lineman) at that point.
We all ride the wave up and back down.
Where you get in trouble is when someone didn't bond something and you get between a bonded and unbonded item. The difference in potential is reconciled across the connecting person.
BTW the code says it is "not necessary" to also pick up the panel and the system grounding electrode. It doesn't say you cant. In fact you will be making this connection via the underwater light J box and the pool pump EGCs. I just stopped being confused about it and took my spa bonding grid straight to the panel,that also catches the pool and all the patio steel, also caught on the pool end. Code also requires that I catch the screen cage which also picks up the "Florida room" that gets tied the the EGCs of all the circuits there. This whole place is just one big bonding matrix.