Feeling a little electricity in the pool

[mirogers1]

I can feel a slight amount of electricity when one hand is in the water and the other is on the concrete. It gets worse when it rains. This even happens when I shut off the main breaker on my house. I've heard it's because of underground utilities. Anyone else had this problem?

[aylad]

There have been others on the forum with similar problems. I can't answer for you, but until those who can stop by, you can use the Google search link in my sig to look for other similar posts.

Welcome to the forum!!

[AnnaK]

A friend of ours in Virginia had that happen several years after her pool had been installed. She discovered it when her dog avoided a particular area of the the pool. They called the PB who did every conceivable check of the system and couldn't find anything wrong but was able to show some electric leakage in the water. I'm not saying this right, it's been a few years. They finally called the electric company which discovered an issue with some ground wires in lines they had installed recently. You might want to contact your utility company.

[PoolDoc]

Electricity and pools mix . . . fatally.

At a minimum, what you are experiencing means you have a bonding failure. Read this post on bonding:
http://www.poolforum.com/pf2/showthread.php?9868-Electrical-Safety-Tips&p=64986#post64986
and ideally, the whole electrical safety thread.

To check out the problem, you're going to need a digital multimeter, like one of those below. You may already have one; if not, all of these are 4+ star rated.
Fluke 87-5 Digital Multimeter @ Amazon (~$310) (http://www.amazon.com/exec/obidos/ASIN/B0002YFD1K/poolbooks)
Fluke 115 Compact True-RMS Digital Multimeter @ Amazon (~$125) (http://www.amazon.com/exec/obidos/ASIN/B000OCFFMW/poolbooks)
Mastech MS8268 Digital AC/DC Auto/Manual Range Digital Multimeter Meter @ Amazon (~$40) (http://www.amazon.com/exec/obidos/ASIN/B0050LVFS0/poolbooks)
Extech MN35 Digital Mini MultiMeter @ Amazon (~$20) (http://www.amazon.com/exec/obidos/ASIN/B0012VWR20/poolbooks)

If you're on a tight budget, get the Extech. It is just an import, but Extech screens the quality, and it will probably do the job. If you aren't so tight, and don't have a good meter, you'll never regret the Fluke 115. The Fluke 87 is a pro-tool, probably more than you need. But Fluke is a great tool -- I had one for 25+ years, till it got too close to a pool :( :rolleyes: and that was the end of my Fluke.

I do so little electrical work that I've gotten by with a cheapy from Northern Tool . . . and it sort works -- roughly like test strips compared to a K-2006. But these are better prices for better meters than I'd seen locally. If I have a good month, I believe I'll get a new meter, too.

Anyhow, you need to get a meter, AND you need to find the power disconnects for all your pool equipment AND for the power service to the pool panel.

You might also want to see if you can get the electrical inspection report on your pool. But, be careful -- if there was supposed to be an inspection, but it was never done, you do NOT want to have an inspector come out and 'shut you down' till 'rectify the deficiencies' by digging up your deck, so he can inspect!

[AnnaK]

Bonding. Yes, that's the word my friend mentioned.

[msumoose]

Ahh, the pleasure of stray current. Had a friend that installed a pool, inspected, all good until he swam and got 6 volts every time he touched the stainless rail at the steps. Pool was WELL bonded and there was no current leak from the house or pumpworks...called out the utilities, and while they were helpful, nothing was found. He could not enjoy his pool and after much back and forth, the phone company finally found an abandoned line that was cut 15 years prior leaking ring voltage into the ground. The moral of the story is bonding works both ways...

[PoolDoc]

Moose,

You're a science teacher. Think about what you're reporting! A properly installed bonding system turns the entire pool and deck into an open top Faraday cage. To the extent that there is ANY potential between one element in the cage, and another member . . . to that extent, the cage is defective.

Granted, under extreme currents (lightning!), there will be a potential across the cage. But even then, someone IN the pool should be in a very high resistance path, compared to all the other available low resistance paths.


Pool was WELL bonded and there was no current leak from the house or pumpworks

In fact, unless I'm really missing something here, your friend's story proves that the pool was NOT well bonded. Having passed inspection (in the past) and being well bonded (today) are NOT the same things!

Lots of things that 'pass inspection' don't remain safe or effective. Conduit grounds have nearly killed me twice, once in a restaurant under the dishwasher (I'm a plumber, and used to do commercial service) and once in a pool room . . . even though both systems passed NEC inspection. (I *hate* EMT and LMT conduit grounds -- I'd outlaw them, if I could! They ALWAYS fail.)

[msumoose]

I get ya, but it still happened! I believe that the builder of the pool bonded everything but the pool. Lights, stair rails, etc, but not the pool itself, and the quickest way to ground was the pool or the handrail (whichever way you want to see it)...and of course, all I had was a visual inspection, and could see the bonding wire and lugs on the visible stuff. All was done correctly, and he had assurances from the builder that it was in spec.

The removal of the old phone line fixed the issue though...

I see in my work that since the popularity of SWCG's the bonding has gotten MUCH better, I guess putting current IN the pool makes some people a little "BOND HAPPY!)

[kelemvor]

I think that the concepts of bonding and grounding are being confused here. Bonding would prevent a difference in potential between the various gear that is bonded together (pump, light, pool, ladder etc). There should also be at least one earth ground on the bonding line. It sounds to me like there is really a difference of potential between the ground its-self and the bonded pool gear. Possibly because the earth ground for the bonding setup was sunk near the pool pump equipment and there is a difference in potential between that location in the earth and the location where this person's pool deck is at. I'm not sure if it's really possible to bond concrete, is it? It might be worthwhile to sink another deep earth ground to the bonding line near the pool and/or decking to try and solve this particular problem. Or it could certainly be a faulty bonding line like Pooldoc said in the first place.

Another thought I had was that if the setup has any significant age, the ground rod could have simply corroded enough that it's no longer serving it's purpose.

[PoolDoc]

I get ya, but it still happened!


All was done correctly, and he had assurances from the builder that it was in spec.

The first quote contradicts the second one.

If everything HAD been done correctly, then the events you described would NOT have happened! Bonding creates an electrical equipotential area. In fact, the full name for bonding IS "equipotential bonding". Equipotential means, you've created an area where the voltage potential is the same everywhere.

A bonded pool area MIGHT be at 300V above / below ground (ie, 220 AC), but within the area EVERYTHING would be at the SAME potential, and you could NOT get shocked, for the same reason a bird on a wire doesn't get shocked: the on the birds left may be a 10KV transmission line, but so is the line on the right, and there is NO difference.

Let me say it again: if a pool is CORRECTLY bonded, you CANNOT be shocked while you are completely within the bonded area. You MAY be shocked when you move from one area to another by, for example, stepping off the deck. But, if you are INSIDE the bonded area, and you get shocked you know TWO things:
1. There is a wiring or voltage problem somewhere
AND
2. The pool is not correctly bonded.

Bonding is PRECISELY intended to prevent the situation in #1 (bad wiring, say in the lights) from shocking people.

People constantly confuse bonding and grounding, even though they are completely distinct. Grounding means tying something to ground potential; bonding means creating an equipotential zone (which the ground is not, because it is a high resistance conductor, allowing local variations in what the "ground potential" actually is). You CAN *ground* a bonded area, but it's also possible to have a bonded area at 1000V above ground. (In actual fact, because of the way pools are constructed, most bonding cages are intrinsically grounded to 'earth' potential.) You can ALSO tie the bounding GROUND to the wiring COMMON, so that there are NO local variations in ground potential in the pool area. (On the other hand doing this can create ground loops, but let's leave that alone, for now. In any case, it's almost impossible to BOND a pool, without tying the bond field both the earth ground AND to the wiring common.)

But, AGAIN: If you get shocked, while you are IN your pool OR ON your deck, from anything other than a MASSIVE current flow (transmission line falling into the pool; lightning, etc.) THEN you KNOW that the bonding is NOT correct.

[BigDave]

Bonding should bond the water in the pool as well as every piece of metal and all other conductive material (reinforced concrete is quite conductive) close enough to the pool that a someone could touch it and the pool at the same time. The bond is there to force all these objects to the same potential (voltage) by carrying the current of any difference with almost no resistance. The OP here clearly has a bonding problem as did msumoose's friend.
I'm not sure Kelemvor, if driven grounds connected to the bond would help or hurt, they represent additional sources of stray voltage. Some codes require pool bond to be connected to driven ground, some do not. My non-expert opinion: the bond must carry the current of the voltage differences around the pool but should not be used to equalize potential accessed by driven grounds.