Pool water electric shock

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Old 08-01-17, 03:35 PM
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Pool water electric shock

The other night after an all day rain I was checking my pool for ph, chlorine and temperature. Pump was running and underwater lights were on. Concrete deck was wet. I went down on one knee and put my hand in the water and received a tremendous shock from the water. Much greater than one of those electric insect racquets. I turned everything off and next day I tried to recreate the incident. Could not to it. Started researching issue.

A few days later family was swimming in pool. All power was off to pump and lights to prevent any shock. Daughter in pool touched hand rail and received tingling like electric muscle stimulater. Grandson too. Everybody out of pool. Multimeter test of all circuit breakers. Found underwater light circuit leaking 1.4 volts when breaker off. It was a GFI circuit breaker. Not working properly. Disconnect hot lead. Tested water. Tingling still evident. Disconnect neutrals and tingling not evident.

So problem with light circuit. Suspect underwater light housing ground deficient or something. Light is putting current into water and person in water touching hand rail becomes grounded and receives shock. I guess that's the same thing that happened to me except the full 115 volts were going into water since light was on. When I kneeled down on the concrete and touched water, I completed the ground and got the shock. Does this seem right to anyone. Any other explanation?

I am correcting all the problems and will have an electrician check everything. Any advice is appreciated.
 
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Old 08-01-17, 04:28 PM
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It sounds like there is no bonding of the water and metallic object near the pool.

I am glad you are getting this serious hazard fixed.
 
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Old 08-01-17, 04:39 PM
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Found underwater light circuit leaking 1.4 volts when breaker off.
If it's a GFI breaker and it's off..... there can be no leakage from it.

It's definitely a bonding problem but not in particularly from one item. What you were measuring is a difference in grounds.

Equipotential Bonding ..... erico/catalog/literature/E673B.pdf

Is this a cement pool ?
How old is it ?
 
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Old 08-01-17, 10:08 PM
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While you are at it...

Consider converting to 12V LED. Fundamentally so much safer, and saves energy.
 
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Old 08-01-17, 11:05 PM
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Although replacing the pool light with low voltage LED has its benefits..... that isn't the problem here. The problem here is difference in grounds creating voltage gradients.


The purpose of the bonding grid in the first place is to ensure every metal component around the pool has the same resistance. That's why the technical name for a bonding grid is an “equipotential bond,” meaning all the metallic components in a pool or spa should have equal resistance.

This is really a very misunderstood subject. Mike Holt, the electrical guru, has several good videos on the topic. One is linked here.... you tube/watch?v=j7r1UyuIgss
 
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Old 08-02-17, 10:40 AM
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Pete; thanks for responding. The pool is not cement. It is some kind of polymer, fiberglass or plastic panels I assume bolted to a frame of sorts with a vinyl liner. The decking is concrete.

I thought the GFI circuit breaker was the culprit because with the hot lead disconnected, there was still a tingling when touching the hand rail. When I disconnected the 2 white neutral leads, there was no tingling. With the GFI breaker on it would not function when the test button was depressed.

I could find no evidence of bonding when checking the railing, ladders, skimmers, and pump; however when working on the power panel I did find a bare wire coming from below the concrete pad the pump is on and connected to the ground wire for the lights. Don't know yet what it is.

The pool is about 10-12 years old. I bought the house in 2011 and the pool was already there. I replaced one pool light 3 years ago. We have used the pool alot during the 6 years we've been here. With lights on at night. We've never had this problem before.

Why did I receive such a shock with the pool lights on? How is the current getting into the water if not thru the breaker and light?
 
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Old 08-02-17, 11:00 AM
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I've seen cases of equipment faults causing the wired grounding system (including the neutral) to be elevated from local ground due to an energized water system. In one case, the electrician gave up after getting a suprise shock at the panel and called the POCO, who then drove a bunch of ground rods at the pole, then gave up that, and ultimately discovered a neighbor with a water heater fault, across the street.
I suppose my story here is that the cause may or may not be the pool lamp, but it could be in the path. This testing would require a pro.
 
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Old 08-02-17, 01:18 PM
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Consider converting to 12V LED. Fundamentally so much safer, and saves energy.
Low voltage lighting is not necessarily safer around a pool -- the lower voltage potential is good, but the addition of a transformer secondary winding is not. It depends on the specific system and how it's installed. Code regulates LV lighting pretty much the same as line voltage.
 
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Old 08-03-17, 09:25 AM
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Why was I shocked

I would still like to know why I got such a higher voltage shock when the lights were on than the tingling when the lights were off. Could that have happened with out some kind of voltage being put in the pool water from the lights? I tried to recreate this shock the next day and could not do it. Could this have been a problem.

I am still assuming there is a light problem since we never experienced the shock for the previous 6 years. Any help here?

BTW I did review Mike Holts's videos and learned a lot. I have tested the voltage drop from the neutral wire at the pool breakers and found it to be .2 volts. There is a transformer within 100 yards of the pool that services my house only. This is county electric service. Nearest neighbor's transformer is over 200 yards away. Next on is 1/4 mile.
 
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Old 08-03-17, 10:23 AM
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I'll bet the issue may be related to the all day rain.

Is all the water piping to the pool PVC?
Is there a buried PVC pipe carrying power out to the pump via a shut off box? Is there a green covered grounding conductor inside that pipe?
Are there any other electrical devices within 20 feet of the pool?
Was the pool pump flooded due to this rain?

Forgive the simple minded questions, but we have no pix to work with here.
 
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Old 08-03-17, 10:31 AM
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Found underwater light circuit leaking 1.4 volts when breaker off. It was a GFI circuit breaker.
A GFI breaker disconnects both the hot and neutral in the off position.

A GFI would normally trip in a fault condition like you are experiencing if there was a voltage leakage to the water.

I still feel you have a bonding problem. Beyond that I'd just be guessing as testing with several meters is required. I think I'd call the town to see if there was an electrical inspection when the pool was installed.
 
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Old 08-03-17, 10:46 AM
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All piping is PVC. The pool pump is adjacent to the Pool pump Circuit box. An underground cable with ground wire runs to the pool circuit box from a second box for all outside power requirements - appx 100 ft distance. Pump is mounted outside on a concrete slab. the pump and slab are exposed to rain. This has never been a problem for the preceding 6 years. I do suspect the rain and wet concrete deck had something to do with my shock.

The only two electrical devices at the pool are the pump and underwater lights. Next closest is 100 ft distance Outdoor power box.

Pool pump is appx 40 ft away from pool.

I think the bare ground wire found under the pool pump concrete pad and connecting to the pool underwater light neutral wire at the circuit box was a poor effort at providing a ground.

I can post pics if you tell me what you want. Remember I have already removed the light GFI circuit breaker and wiring from the box. So no power can get to the lights from the box.
 
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Old 08-03-17, 11:06 AM
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I think the bare ground wire found under the pool pump concrete pad and connecting to the pool underwater light neutral wire at the circuit box was a poor effort at providing a ground.
verify this statement?? if true, bad, bad.

A picture inside the pool el box would be great. Need to show the grounding conductor(s)
 
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Old 08-03-17, 11:41 AM
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I think the bare ground wire found under the pool pump concrete pad and connecting to the pool underwater light neutral wire at the circuit box was a poor effort at providing a ground.
This could possibly be the issue if the neutral is bonded to ground at the pool subpanel.
 
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Old 08-03-17, 05:21 PM
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PVC IS the choice to use now. There should be an insulated green wire in the conduit the same size as the hot and neutral that connects to the light. There also needs to be a green solid #8 wire that goes to your pools bonding. That #8 is supposed to be connected to the metal pool light niche.

That #8 could have been run inside the conduit or is usually run on the outside but does get connected inside the wet niche.

This same #8 green wire gets connected to the pools framework...if metal, handrails... if metal, ladder... if metal and definitely to a lug on the pump motor and then back to the panel ground connection.


I thought the GFI circuit breaker was the culprit because with the hot lead disconnected, there was still a tingling when touching the hand rail. When I disconnected the 2 white neutral leads, there was no tingling. With the GFI breaker on it would not function when the test button was depressed.
If the breaker was on but the hot was disconnected..... the neutral is still connected. The test button wouldn't work without the hot connected.
 
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Old 08-07-17, 07:45 AM
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attached are pics.

The two open panel box pics show the GFI breaker for the two underwater pool lights removed along with the hot lead going to the front blue conduit and also the neutral going from the blue conduit to the neutral rail of the circuit box. These have all been removed by me to prevent any electricity from getting to the pool thru the lights.The first blue conduit goes to the lights and the second brings power from the outdoor circuit box 100 feet distant. The orange cable coming into the panel box on the lower left brings in the two power wires to the circuit breaker from the pool pump.

The ground wire I found coming from under the concrete pad is seen on the front of the blue conduit and is attached to the ground wires of the lights . Remember all wires attaching to the Light GFI circuit breaker have been removed.

The Pool pump area pic shows the circuit box and outside area of the pad. In the background is a propane water heater for the pool that had been disconnected prior to my buying the property. It has not been reconnected by me. You can see the propane distribution pipe sticking up in the background. There was no circuit breaker in the panel box for the heater although the power cable for the heater is still present. The only w2ire connected to the pool pump is the power wire coming from the panel box.

The wire to open box pic shows a metal wiring box that was present when I bought the property 6 years ago. Since only the one wire was connected to it, I had not looked at it until just the other day. Had to drill screws out to get top off. Don't know yet where the wires go. This could have been a connection for the heater. If so there were no wires connecting it to the panel box so it might have connected to the out door panel box mentioned earlier. Still checking on that. Could be another explanation.
 
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Old 08-07-17, 07:58 AM
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Yikes! This pool wiring is in pretty bad shape. I'm not surprised something is causing a shock. The bare neutral and no ground is certainly enough to cause it.

It could be a big project, but if it was my house I'd start over. Leaving this like it is would be too dangerous for my comfort.
 
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Old 08-07-17, 11:25 AM
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I have to agree.

From the picture it's extremely hard to tell what's going on. I'm not used to seeing that type flexible tubing used in pool wiring. It looks there may be a cable inside the tubing which is also incorrect. The ground wiring is to be insulated separately which it's not in a cable.

Looks like two white wires.... one large and one small feeding that box.

There are very detailed and specific methods to wiring a pool and it doesn't look they were used there.

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Old 08-07-17, 02:26 PM
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PJmax, ibpooks; I agree the wiring could be better. Sorry about the bad pics and explanation. However the bare wires are not the neutral. They are the ground wires from the cable going to the lights. Had I taken pics before removing the GFI breaker and wires you could have probably seen it easier.

The wires feeding the box are from one underground cable. It enters the box from the 2nd, blue conduit. The outer sheath has been removed from the white wire and the other black wire is still encases in the original gray sheathing but the light makes it look white. They are the same size wires and are in one cable.

Since I have seen the box so many times I did not realize the pics were so bad. I will make new pics and post them. I do appreciate your help.
I had been planning on replacing this box with a new box with a timer and moving it closer to the pool while maintaining safety limits, but had to do a major repair on my vinyl liner that took up the early summer. The shock to me occurred in the 1st week of having the pool open. I had been in the water many times but without the pool lights on.

I have been researching methods of wiring pools and also bonding and such. This is my current project. I will have a licensed electrician familiar with pools check it out. Still wondering why I got shocked when we had swam with the pool lights on many times in the past 6 yrs. Want to make sure I correct the problem. Could the pool water and liner/concrete act as a capacitor. Me kneeling on the wet concrete and touching the water then discharging it. Just an idea. The current has to be getting in there somewhere.
 
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Old 08-07-17, 03:02 PM
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If the pool light power is being returned into an open ground instead of an intact neutral, you can get an entire area charged including the water.
 
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Old 08-08-17, 07:28 AM
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telecom; I realize in my earlier post that I said the ground wire coming from under the pad was connected to the neutrals for the lights. This was wrong. The ground wire was connected to the ground wires for the lights and then to the neutral bus.

The neutrals for the light were returned to the grounding bus in the box. I removed the GFI breaker and all wires connecting the lights to the panel box. So you will not see a wire connecting the light neutrals to the bus.

What you see in the pic are the two neutral wires to the lights with a green cap in the blue conduit and the two hot wires to the lights with a red cap in the same blue flex conduit.

The bare wires are the grounds.

PJmax; The hot wires feeding the panel box are from one cable. the cable is split just as it comes out of the back blue flex conduit. Hard to see. The sheathing is not removed from the wires but was turned in the earlier pic so that it appears that way. You can see it better in this pic.

Anyway i am going to replace and move the panel box as i stated in a earlier post. Haven't decided if I will reconnect the lights then.
 
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Old 08-08-17, 07:33 PM
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Yikes! This pool wiring is in pretty bad shape. I'm not surprised something is causing a shock. The bare neutral and no ground is certainly enough to cause it.
Agreed! This is definitely a half fast job! In addition, the blue flex, ENT,is not to be direct buried in earth nor is it to be exposed where subject to physical damage. Even if an inspector would allow it, it must be terminated in a PVC connector and cannot just be stubbed into the subpanel. I see a big PIA job coming up for someone.
 
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Old 08-09-17, 07:45 AM
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I really do appreciate everyone's comments. This Pool is located in North east Alabama. Not within any municipality. No building permit required. No inspection required. I want to fix it but i don't want to fall prey to the same problem the last home owner did when he installed the pool. Allowing substandard work since no permits/inspection. I want to know as much as possible and fix this. I will then get a pool company or a qualified electrician to inspect the work. But i want to know what he is talking about when he tells me something isn't right. Plus I want to be able to tell if he knows his stuff. I should have done this several years ago.

BTW I had the local pool company out when I bought the house and although the pool looked OK had them clean and inspect the pool. Also had a home inspection done before I bought the property. No problems with the pool identified. No mention of bonding or any other inappropriate things that have been pointed out.

Again thanks again. Please continue to comment as I post new info and pics.
 
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Old 08-09-17, 08:14 AM
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How far is the pool panel from the panel which feeds it (I assume the house main)? This is really the biggest part of the job as there needs to be a new feeder installed in rigid PVC conduit with four insulated wires. Unfortunately the UF-B cable they used only has three and one is uninsulated, and that's the real root of this problem. Pool equipment needs the separate ground and neutral in the feeder and also needs the bonding wire to the pool equipment, surroundings and water itself. I don't see any other way to get there than replacing the feeder back to the house.

As somebody mentioned a ways back there also needs to be a water bonder, which is essentially a piece of stainless or brass which is mounted in the water and also connected to the bonding wire which lands on the pump frame, metal ladders and concrete deck rebar if you have it. This keeps all conductive parts of the pool system at the same electrical potential so even if there is some stray voltage in the pool system you have a much lower chance of shock for example grabbing the ladder when you climb out of the water as both the water and ladder should be at the same voltage potential.
 
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Old 08-09-17, 09:34 AM
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ibpooks; Thanks for your response; the box for the pump is 30 ft or so away from a 100 amp panel box that services other outdoor items. No problem with running buried conduit with 4 wire service. Will replace the panel box and pump breaker. Will also do the bonding somehow. Been thinking about it. Will leave lights unpowered until I am satisfied the wet niche and transformers are OK. Then will put in GFI breaker for lights if I decide to power them.
 
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Old 08-09-17, 09:43 AM
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No problem with running buried conduit with 4 wire service.
Just a note alll ground wires must be insulated which you have written is not the case there.
The bare wires are the grounds
Also had a home inspection done before I bought the property. No problems with the pool identified.
Even on residential electrical they often miss even the obvious. They are not trained electricians and pool electrics are even more complicated.
 
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Old 08-09-17, 10:53 AM
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ray2047; Thanks for your comment. Those bare wires in pic are insulated along with the hot and neutral in the gray sheath. the sheath has been cut away for them to be twisted together. My cmt about the bare wires was meant to only differentiate them from the neutrals in the other posts. Some one thought the bare wires were the neutrals. I had miss-stated that earlier.

Again the bare wires in the pic are the ground wires and are insulated in gray sheathing.

I will replace this entire box and wiring.

Agree on the home inspection.
 
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Old 08-09-17, 11:20 AM
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Again the bare wires in the pic are the ground wires and are insulated in gray sheathing.
That sounds like UF cable. Cable can not be used because it has a bare ground. The gray sheath does not count as insulation. Insulation would be a green jacket on the wire itself.
 
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Old 08-09-17, 01:37 PM
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It is UF cable. Are you referring to wiring underwater lights?
 
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Old 08-10-17, 09:03 AM
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That's true Ray, UF cable cannot be used for any outdoor portion of a pool or spa wiring.
 
 

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