How do i test this

[Jerseydaze]

I have a customer that has a 30 year old pool .They switched to a salt water system .Since changing over they feel a tingle/shock when stepping out of the pool. How do I meter this to isolate it source or what do I do to resolve it?

 

[big john]

Figure out what points they are touching when they feel a shock: Use a high-impedance digital meter to look for voltage between those points. If you suspect the water itself is being energized, then put a conductor in the water to measure against; the larger the conductor the better the measurement.

Inspect any accessible grounding and bonding, including pump case bonds. Pay special attention to any new equipment installed for this setup. Check to be sure that GFCI protection is present and tests properly.

If possible to test or feel voltage, shut off all power and turn on circuits individually until the problem returns. The last circuit is the likely culprit.

Just be aware, sometimes voltage gradients are related to utility problems and have nothing to do with homeowner wiring, so shutting everything off may not even solve it. More bonding may reduce it, though.

 

[Smart $]

What two points is the person touching when they get shocked? That's the points to at least establish voltage, which will increase as you reduce resistance of pathway(s) to source and vice versa.

Does the pool have any conductive parts in contact with the water?

Does the pool have an equipotential ground grid?

In some cases, an off-premises fault will use on-premises earth and bonding as a pathway for fault current to return to its source.

 

[Fulthrotl]

I have a customer that has a 30 year old pool .They switched to a salt water system .Since changing over they feel a tingle/shock when stepping out of the pool. How do I meter this to isolate it source or what do I do to resolve it?

salt water, i am speculating here, is a bit better as an electrolite than
unsalted water, altho the salt content is pretty minimal in a salt/chlorine
system.

so instead of thinking the salt made the difference, i'm gonna think something
that got wired or rewired when the system was upgraded is leaking.... and there
most likely will be a gradient involved. a few years ago near where i live, two kids
were in a pool, and found that there was a tingling when they swam near the
pool light, so they, being 10 years old, decided to see how close they could swim
to it. it killed one of them.

my first thought is to megger between the pool equipment/ground, and the wet niche
fixture bezel. i've done this in the past by taking a fluke megger, and taping one lead
to a piece of PVC conduit, holding it on the bezel, and meggering to a wire attached to
the equipment ground. with a fluke, i'm looking to put it on 1000 VDC, and see only one
volt of potential maintained across the meter.

disconnect the timers, and pool controls before doing this. you want to see if there is
any difference of potential possible between ground and pool water. with that set aside,
start testing one thing at a time, until you find the leak....

 

[brantmacga]

Mike Holt posted a video of this exact thing a couple of weeks ago. I shared it on NEC forum; do a search and you'll find it


Sent from my iPhone using Tapatalk

 

[Little Bill]

I have a customer that has a 30 year old pool .They switched to a salt water system .Since changing over they feel a tingle/shock when stepping out of the pool. How do I meter this to isolate it source or what do I do to resolve it?

Start by checking the salt generator control box to see if its bonded. I say that because you said they noticed the shock after installing this. There should be a lug on the outside of the box. If there isn't a bond wire on the box then run a #8 solid conductor from it to the pump motor or to the existing bond wire.

If that isn't it search on YouTube for what Brantmacga said. Type in "Mike Holt swimming pool bonding" There are (I believe) 3 parts to it.

Warning! The customer might not like the outcome if tested and no bonding. They will have to bust up some concrete and bond the pool and equipment.

 

[mgookin]

Warning! The customer might not like the outcome if tested and no bonding. They will have to bust up some concrete and bond the pool and equipment.

I'd rather dig a hole 3' deep than 6' deep!

The first thing to do is immediately LOTO the pool so nobody gets killed.

 

[Little Bill]

I'd rather dig a hole 3' deep than 6' deep!

The first thing to do is immediately LOTO the pool so nobody gets killed.

Me too, I was just saying people get upset about small things and don't consider the larger if the smaller is left undone.

 

[brantmacga]

Start by checking the salt generator control box to see if its bonded. I say that because you said they noticed the shock after installing this. There should be a lug on the outside of the box. If there isn't a bond wire on the box then run a #8 solid conductor from it to the pump motor or to the existing bond wire.

Yeh, that's where I would start. That seems likely to be the problem.

If that doesn't fix it, you may check with the utility. Down here, GA Power has a power quality office that will send engineers out to help.