ECN Forum Forums Code Related Discussion NEC & other Code issues Equipotential Bonding Grid

It depends on how many people peed in it.

If I get some spare time I will set up my conductivity experiment again. It was a white bucket with two one foot #10 probes in contact with water and 8" apart in series with a 60w light bulb.

I did this a while ago and was surprised at how little salt it took to get the bulb to glow. I now have the ability to test for total dissolved salts content. I can't find my results but I did plot current and voltage drop for various solutions.

I have inspected many pools over the last 10 years as an AHJ and I have never seen stray voltage a problem with pools that have rebar in the gunite or pools with metal sides. The only time I have seen stray voltage problems is with the fiberglass pools. There have been at least 2-5 times I have heard about these problems. The one pool had 15-30 votlts between the handrail into the pool and the concrete deck. Another pool had over 50 volts from the deck to the wet niche light.

Harold (or others), What is the best way to check for these stray voltages?
I have done the meter trick with a probe in the water etc.
My inground liner pool (20+- yrs) has checked out fine to me.
Just looking for perhaps a more true measuring meens.
I think in the spring I will do the pool water bond thing to it.

Although it is not the best way to test it, actually getting a tingle while you are in the pool is usually what prompts the call.
If I was going to "probe" the water I would clip my lead to a foot or so of aluminum foil and drop that in the pool, then measure to anything you can touch. I would still be skeptical of any reading I got with a digital meter without a couple hundred k shunt.
You may already have some bonding going on if you have a regular pump (not double insulated). If you have a heater there is plenty of bonding going on.
Probably the most effective bonding would be a bonded metal ladder in the water.