Pool Bonding and Grounding Missing

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Dave Ferra

Member
Location
San Francisco
Occupation
Pool Repairs and Remodeling
I realize you must get inundated with calls about weird electrical findings and people asking what to do about it. I hope you might find the time to think about our results here.



We have an outdoor, in-ground, gunite and plaster pool at an apartment complex. There was a report (we were not able to get the report directly) from one of the bathers that they felt a “tinkle” when they believe they were in the area of the pool light. I believe the light was off at the time.



We decided to do a bonding and grounding test on the structure. Here is what we found on our initial arrival:

The pump and heater were bonded together with a #8 wire that also went to one of the copper suction lines of pool.

We did not see any copper wire going into the ground.

There was no #8 tied to the circuit breaker panel within the pump room.

There was normal ground leads within the breaker panel and the pump and heater.

The pool light junction box was not a normal “pool light” junction box. It was a usual 4 square box. The conduit containing the light’s cord was pvc and does not look original.

There is a #8 wire coming out of the ground outside the light conduit and ties to the 4 sq box.

There is a #8 insulated green wire within the light conduit coming into the 4 sq box and tied to the common electrical bar there.

There is a ladder and a handrail (metal) mounted to the deck and drop into the pool’s water.



We tested for both resistance and NEV. First we ran a cable from certain points of the equipment/ladder/handrail/light on the ohms scale. We then drove a screw driver into the ground, far from any electrical service, and took voltage measurements to various pieces of the equipment. We got what we considered to be very confusing results. I have list them below:



Voltage – Measuring from dirt/screwdriver to . . . . . .

Handrail 0.024 volt

Ladder 0.014 volt

Light body 0.014 volt

#8 bare copper

wire at light J box 0.014 volt

Pump and heater

#8 wire 0.014 volt

Time clock box 0.014 volt

Concrete decking

(wet) within 3 ft

of pool edge 0.012 volt

Water in pool 0.029 volt

Breaker panel 0.014 volt

Gas pipe 0.093 volt

Probe in air 0.005 volt



We then measured the resistance from various points to other points within the pool area. We got:



Water to:

Handrail 1.103 Mohm

Ladder 3.338 Mohm

Light body negative 0.293 kohm

Pump/heater negative 0.393kohm

Time clock negative 0.360 kohm

Breaker panel negative 0.324 kohm

#8 bond wire at

light J box first was at OL then went to negative 0.296 kohm



Then tried handrail to:

Ladder 2.95 k ohm

Light body negative 2.205 kohm

Pump/heater #8

bond wire Negative 2.206 kohm

time clock negative 2.150 kohm

Breaker panel negative 2.1665 kohm

#8 bond wire at

light J box Negative 2.205 kohm



The tried ladder to:

Light body Negative 3.305 kohm

Pump heater #8

bond wire negative 3.420 kohm

Time clock negative 3.42 k ohm

Breaker panel negative 3.470 kohm

#8 bond wire at

J box of light negative 3.305 k ohm



I am assuming there must have been some voltage present to give us a negative reading on the ohm scale. But I cannot make any meaning out of it. Off hand I can reasonably assume the deck, handrail, ladder and light body are not fully bonded. It also appears there is a break in the #8 wire that comes from the ground at the light’s J box for the pool light.



I am sure the pool was built prior to the rule establishing the need to bond the decking around the pool shell. So I am kind of ignoring that for now. There have not been any complaints other than the unsubstantiated report of the pool light tingle.



What pattern I am missing here?



Thanks in advance for your help.



Sincerely,



Dave Ferraresi

DF/mc
 
I think you are going to have to hire someone competent to deal with this situation. I do not think this is a situation you can handle on your own, based on some of what you wrote which uses terminology that suggests maybe your familiarity with this kind of thing is limited.
 
Dave Ferra said:
I realize you must get inundated with calls about weird electrical findings and people asking what to do about it. I hope you might find the time to think about our results here.

We have an outdoor, in-ground, gunite and plaster pool at an apartment complex. There was a report (we were not able to get the report directly) from one of the bathers that they felt a “tinkle” when they believe they were in the area of the pool light. I believe the light was off at the time.

We decided to do a bonding and grounding test on the structure. Here is what we found on our initial arrival:

The pump and heater were bonded together with a #8 wire that also went to one of the copper suction lines of pool.

We did not see any copper wire going into the ground.--There is no need for the #8 to go to the panel or to ground although it basically would be connected to ground thru the panel and the equipment grounding conductor of the pump

There was no #8 tied to the circuit breaker panel within the pump room. #8 would not be tied to the breaker nor as mentioned tied to the panel

There was normal ground leads within the breaker panel and the pump and heater.

The pool light junction box was not a normal “pool light” junction box. It was a usual 4 square box. The conduit containing the light’s cord was pvc and does not look original. This is a violation

There is a #8 wire coming out of the ground outside the light conduit and ties to the 4 sq box. Correct but again the box is incorrect

There is a #8 insulated green wire within the light conduit coming into the 4 sq box and tied to the common electrical bar there.

There is a ladder and a handrail (metal) mounted to the deck and drop into the pool’s water. These should be bonded with the #8 that ties to the pump and heater



We tested for both resistance and NEV. First we ran a cable from certain points of the equipment/ladder/handrail/light on the ohms scale. We then drove a screw driver into the ground, far from any electrical service, and took voltage measurements to various pieces of the equipment. We got what we considered to be very confusing results. I have list them below:

Sincerely,



Dave Ferraresi

DF/mc
Click to expand...
 
I would be more than happy to turn this over to an Pro. Unfortunately, the ones I have tried to contact seem to have no idea where to begin. By the way, I am aware that some of the items listed (like the 4 sq box light j box) are violations and that #8 does not go to the breaker panel. But I wanted to point out that whoever came before us did not go crazy and try to bond everything on one grid. But on the other hand they did not bond handrails, ladders, pumps/heaters, etc.

Any ideas on what questions I can ask a potential electrical contractor to get an idea if they can handle the situation?

Thanks,
 
At at Mike Holt grounding and bonding seminar recently, he said to run not walk from any issues with stray voltage in a pool.
If you get involved and, and there is an incident, you would be liable.
 
tom baker said:
At at Mike Holt grounding and bonding seminar recently, he said to run not walk from any issues with stray voltage in a pool.
If you get involved and, and there is an incident, you would be liable.
Click to expand...
Thanks. I already getting on my running shoes; but need an idea of how/who to get too come out and look at it.
 
Dave Ferra said:
Thanks. I already getting on my running shoes; but need an idea of how/who to get too come out and look at it.
Click to expand...
The problem is the entire pool shell and perimeter need bonded together. You can bond the ladder, the light shell, and other somewhat easier to get to items, but just having a 10 foot x 10 foot hole in a random spot in the equipotential bonding of the pool shell still creates a hazard to pool users.

What some don't understand about this is we are not "grounding" all those items we are "bonding" them so they are all the same potential.

You can have a two volt to earth potential on incoming service grounded conductor - might not even be a problem with your premises, could be voltage drop on the POCO's primary neutral, but it is bonded to your service grounded conductor so that two volts is imposed on your service grounded conductor, which is also bonded to all your equipment grounding conductors and items associated with the pool.

So we bond everything in and near the pool to make everything the same potential, this means the user touches the ladder to climb out of the pool , it is same potential as the water and the pool shell which they may also be in contact with. Doesn't matter that there is 2 volts to earth, unless that pool shell isn't bonded, or there is one section in the shell that has a hole in the bonding then it is at earth potential and there is possibly 2 volts to it from the ladder or the water and the user crosses that when they touch it or it at least increases voltage exposure the closer they get to the shell.

Nobody that knows what they are doing wants to touch it without doing some extensive work to ensure they know what they left behind, owners likely want a quick fix, which there is none.
 

Yup, the 4x4 box no good. There are specific deck boxes for pool lights. They have a cord strain relief clamp to prevent the pool light cord from being pulled back toward the pool.

I would reach out to a local pool contractor and ask them for a reference on an electrician they use. They should know what to do. Some of the
electricians have a certification to perform a bonding test. You'll get a written report.

The rail set in the water on the step is doomed. The chemicals will eat it apart and you'll lose the bond. Most of them I see are aluminum. If we do set a handrail or ladder we'll use a bronze escutcheon. It'll take more abuse. And if a set of steps is very long, we'll have a custom rail made so we can deck mount it rather than mounting on the deck and the step.

I would shut the pool down until this is resolved.
 
We regularly test pools for bonding, grounding and voltage issues. Not sure where you are located but SOME NETA firms will have experience in testing POOLS,
 
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