pool shock

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bc

Member
In ground concrete pool with fiberglass spa w/fountain attached. Common cool deck around everything. Up to 1.5 volts between the spa water and the pool water. I can feel a tingle when I put one hand in the spa, and the other in the pool. 12 volt light in both the spa and the pool. Heat pump type heater seems to trigger the event, but when it is turned off, I still get the voltage. It is intermittent, with no set pattern as to off and on. I am looking for ideas, suggestions, experiences, etc. as to what might be the problem. I did not do the original installation, so I cannot tell you if it was properly bonded. I get good continuity from the light fixtures trim ring to the handrails and the #8 at the pump and heater. It appears that there is a #8 from each wet niche back to the pump/heater area, both tied under a mechanical lug on the heater, with one continuous to the pump motor. Any input would be greatly appreciated. p.s. I am new to this forum, and apologize if this is posted in the wrong place. Thanks in advance. bc :confused: (Also, does the NEC require the bond to be continuous with no splice, and should the spa/fountain be GFI protected?
 

websparky

Senior Member
Location
Cleveland, Ohio
Re: pool shock

NEC 2002 680.23 Underwater Luminaires (Lighting Fixtures). (A)(2) Transformers. Transformers used for the supply of underwater luminaires (fixtures), together with the transformer enclosure, shall be listed for the purpose. The transformer shall be an isolated winding type with an ungrounded secondary that has a grounded metal barrier between the primary and secondary windings.
I would be sure that the transformer is a listed one for pool lighting.

Is it a fountain or is it a spa? What is the voltage to it?
 

bc

Member
Re: pool shock

It's a spa with a blower (220 volt), and there is a little fountain nozzle in the middle of it that is on when the pool pump is on (also 220 volt). If I remember right, the transformers were listed for pools. I checked so many things so many times it is all starting to run together in my brain. Thanks.
 

pierre

Senior Member
Re: pool shock

Hello BC

Yes the spa does require GFCI protection.
I would be very careful in how you conduct your present work at this location. IN WRITING I would notify the owner that there is a potentially hazardous situation and advise them not to use the pool until you find and correct the problem.
I recently ran across this same situation last fall. I notified the owner and they 'flipped out'! Our final resolve was to rip up the concrete deck to run bonding, run new feeders to the pool panel (there was NO EQUIPMENT GROUND CONDUCTOR run in the pvc conduit), and rewire all the violations we found. It cost them about $15,000.00. They could not thank us enough when we finished, they had purchased the house because of the pool.
Good Luck, cover your @#s!!!

Pierre
 

bubs

Member
Re: pool shock

I am having the same problem with a inground pool and spa. Power co. says it is stray voltage.Gets worse in the afternoon. All tests have been made by a group of electrical engineers. Still have not solved the problem.
 

brian john

Senior Member
Location
Leesburg, VA
Re: pool shock

All test have not been made or they would have found the problem. These "STRAY voltages come from a source, it takes perseverance to locate the source. Utilizing a multimeter, amp meter and gauss meter, the problems can be located.

Start isolating loads, sources till the source is located.

My old boss use to say "The last test you make will locate the source of what ever problem is stumping you".
 

bubs

Member
Re: pool shock

Sorry my friend but the voltage is still there even with the conductors disconnected from the breaker in the main panel. Georgia Power has researched this problem and says that it only happens once and awhile. Some dairy farmers have this problem at the dairy barns. Shocking the cows. They say the sun is generating the voltage.All help will be appreciated. Thanks
 

brian john

Senior Member
Location
Leesburg, VA
Re: pool shock

Then you have a starting point locate the utility ground or grounds and measure the current, work with the local utility and see if you can isolate this transformer.

Is this a residential neighborhood with copper water pipes? Or are any of the neighbors having neutral ground current on their GEC? Or other associated electrical anomalies. Is there current flow on the ground with the service disconnected? Is this an under ground service?

Was the pool properly bonded when it was installed? Does additional (temporary) bonding above ground minimize the problem?

Have you used an O'scope to identify the waveform?

You can locate the source, eliminating it might take a bit more work.

Can you tell if the voltage is present between two metal structures, can you measure this voltage? Does current flow, between these structures?


There is always one more step till you find the source.

Not knocking electrical engineers, by any stretch of the imagination (I work with several utility co. engineers that know their way around trouble shooting). My company is also hired by engineering firms to solve problems like yours.

Standard trouble shooting procedures SHOULD be able to locate the source, but you have to keep taking it one step further.
 

rrrusty

Senior Member
Location
Colorado
Re: pool shock

BC also look for any underground power lines in the surrounding area (there may have a leak in the insulation) have UFPO come out and do a locate of the surrounding area; Is the area feed with an ovhd service? If so look at the utlity poles in the area for a bad ground/connection that runs down the pole
 

hurk27

Senior Member
Re: pool shock

BC
Is this pool being fed from a sub panel?
If it is there a bond between the neutral's and grounding conductor? any time a bond is made between the neutral and a grounding conductor there is the potential for the voltage drop of the neutral to be placed upon the grounding. This voltage drop will place a differential voltage between the grounding and earth. this can be a shock hazard if it is high enough. this is why there should be a separate grounding conductor ran to any sub panel feeding a pool since GFCI protection is usually made at this panel no ground fault will be detected and they wont trip until a fault is made after the GFCI breaker
The other thing will require a Amp-Probe, put a amp-probe on the water ground if you have an unusual high reading you probably have a bad neutral connection on the service check to see if there is any devices that might be pulling power from the grounding or water pipes,duct work etc...
A good way to determine if the power is coming from this house is to turn all power off at the main panel of the house if the voltage goes away then one by one start turning each breaker back on to see which circuit is causing the voltage. I don't think that you are feeling a voltage of 1.5 or a battery would be shocking you I think there is some grounding that you might be getting a bit more voltage from. to check this run a wire to a remote point in the yard and connect it to a 2' driven rod then measure the voltage to all exposed metal in and around the pool and spa. then repeat the steps above to locate the source. even follow it through to the panels if the voltage is still on the grounding at the main panel and you have made sure it's not a bad neutral then lift the water ground if the voltage goes away there has to be a service down the road that loss there neutral. Be careful as if this house and another is the only two on this transformer lifting the ground can cause damage to the other house. a better way to see this without lifting the ground is with a amp-probe on the water ground with the main turned off if there is still high current on the ground then it is coming from the other house and the only neutral that house might have is the water pipe in your house. so the poco must be advised so it can be corrected.

One thing that would be out of your hand but you might get a POCO engineer to listen to you, it is this if the common or neutral grounded circuit conductor on the primary is lost between the feeding end to the transformer feeding this house it would place a load on the grounding of your house as this is where the transformer is getting it's return power from now this would elevate the voltage on the grounding so if this is the case I would not disconnect any grounding for the service as you could be getting the whole primary voltage across the point of disconnection and could be fatal. a good way is to do a voltage check at the transformer pole from the GEC running down the pole to a driven 2' rod placed away from the pole if there is voltage then you must contact the POCO as any one being able to touch this GEC could get a shock. this might be a quick way to get the POCO to fix it.

[ August 27, 2003, 02:14 AM: Message edited by: hurk27 ]
 

bc

Member
Re: pool shock

I am sorry I have not replied in awhile. Thanks to all of you who took the time to try to help me out. I came in on the job only after the customer started getting the shock. Another contractor was responsible for the installation. I agree that further troubleshooting is needed, and that there is a solution, however, it also becomes a question of how much the owner wants to spend. I have not heard back from him since my visit. My guess is that this is all going to litigation between him and the pool contractor, and their subs. If and when I find out what the deal was, I will let you all know. Thanks again, and God bless you.
bc.
 

bennie

Esteemed Member
Re: pool shock

As long as we keep pumping electrons into the dirt, this pool shock will continue.

Law suits go nowhere. One professional witnesses will testify why it happens, another one will testify why the first one is wrong.

One sure method is to bond the dirt to the water. This is done by filling the pool with dirt instead of water.
 

photon

Member
Re: pool shock

I noticed you said GA Power (meaning probably Buckhead area in Atlanta). Similar problem - voltage present enough in a pool to keep the dogs out, owners could swim but were shocked touching anything grounded when they were exiting the pool. We drove a 30ft ground rod and bonded everything in sight (I later learned how electricity REALLY ACTS). We found the problem by killing power to the property, and then taking a digital voltmeter, sticking the test probes into the pool water and the earth (following increasing voltage), found the stray voltage coming from a neighbors' house, particularly the de-tached garage (bonded neutral/ground in a sub-panel with bathroom water connections and a 50kW back up generator with multiple "illegal" ground/neutral bonds. Amazing, but everything was quickly cured (though I was always watching for buckshot in the backside).
 

brian john

Senior Member
Location
Leesburg, VA
Re: pool shock

In the short time I've been on this site I have seen numerous questions asked regarding all kind of electrical problems. The fact is diligence will solve ALL problems, this field we work in is not governed by magic, that stick (ground rod) we drive in the ground doesn't allow all the spare electrons run to mother earth for fortification before they strike again and driving another stick is not the solution to every problem.

There are solutions to all electrical problems, the firm I work for solves problems for other electrical contractors, most of the problems we solve are simple and are usually the next step in a progression of steps required to solve that particular problem. The contractor either gave up to early or felt that FM (FXXX Magic) was responsible. I hear this all the time (FM that is), thank goodness other wise I might starve.

Oh yeah, I just lost a job with net current problems to an electrical contractor that told the management firm that the grounding electrode system was in adequate and they need to replace the ground rods with a new updated ground grid. Just frustration here.
 
Re: pool shock

I ran into a problem some what like yours. There was a metal drain that went around the pool. The corners were made of copper and the drain was stainless stell. They were using a cleaner that would make up a battery with the two kinds of metal. It was very hard to find.
 

karl riley

Senior Member
Re: pool shock

Brian, you may get that job after they fire the contractor.
We have evidently had similar experiences. I am always confident going into a job that has stumped the local electricians and engineers simply because electricity is completely logical. It is always flowing from the higher potential to the lower, and the lowest is at the Tformer X/O point.

It is common to run into engineers, etc. who have given up because "currents like these are very common" or "it could be coming from a variety of sources (end of subject)".

I like the technique of the fellow on this thread (don't have his name in front of me) who after putting in a 30' ground rod (makes no sense) then placed rods around and measured voltage so that the voltage differences lead him to the offending garage with its Bennie-approved N/G bond (sorry Bennie, couldn't resist).

Well, I better sign off.

Karl
 

brian john

Senior Member
Location
Leesburg, VA
Re: pool shock

Karl:

The management company has contacted me wondering if my price is still good, seems the new ground electrode system did not resolve the problem.

Looked at a temporary HVAC plant for a facility yesterday, with 60 Hz. ground current everywhere.
The difference here is all loads are 480 VAC 3 phase 3 wire. The currents range from 2 to 32 amps in different portions of the plant.

The reason we were contacted was the mechanical contractor had to replace all the metal piping, his water treatment contractor told him he thought the problem was electrical in nature. Whether this is the case I don’t know I only know what I found and either we or someone else will try to locate the source of the current.
 

mbm1953

Member
Re: pool shock

I am the owner that BC initially wrote about with the low voltage current in the pool. The problem is still ongoing and I have tried to be here anytime anyone was doing troubleshooting. I talked with BC yesterday, that is how I happened to find this site, gave BC an update of the situation and will try to do the same here. Just so you know,I do home remodeling and my electrical knowledge is limited but growing.
The pool/spa does have a sub panel, and the only sure way of eliminating the source is to disconnect the grounding wire coming from the main panel. The electrician who did the initial work on the pool installed a grounding grid, three ten' grounding rods in a triangle, in addition to the origional house ground.
FPL (Florida Power/Light) has been out here continuously. They have pulled my meter and disconnected service to my house, removed power from the transformer providing service to my house and the four others that the transformer None of that helped. When reading the voltage in the pool, usually about 1.0 -1.5 volts, you can lower the voltage by attaching #6 copper wire to the hand rails, from the spa and then putting them into the pool. Each wire that is put into the pool lowers the voltage a little bit or makes it rise if taken back out. The last time FPL was here, last Wed, they are convinced the steel around the pool is not properly bonded.
This has been a continuing problem since June 5th and I am at a loss and as you can imagine frustrated since the company who built the pool point to FPL and FPL points to the pool company. I will say that FPL has been here continuously and tried to resolve the problem unlike the pool builders.
 

rickcham

Member
Re: pool shock

mbm

Sorry to hear about your situation with the pool,
I was wondering if when they were installing the pool you may have taken photos of it as it was constructed. I would be interested to see if they bonded the the pool steel.

To Bennie and all the others you folks should put these post in a book, Your ideas on the trouble shooting is interesting and helpful
 
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