Equipotential Grid - Pool

[don_resqcapt19]

You would think they would have had to had some substantiation , i.e. testing, before they made it code. Now there are thousands of these pools out there that are a potential danger.

Not sure there was. Part of the substantiation for proposal 17-115 for the 2008 code.

Discussed during the 2005 cycle but not clearly addressed were pools that were unpaved within the 3 ft area around the edge of the pool. As the shock hazard potential exists with unpaved earth as well as concrete or various types of pavers, this section was expanded to clearly address bonding to all types of perimeter constructions. Proposed 680.26(B)(2)(b) text is a new bonding option. Due to the limited width of the perimeter surface, a single 8 AWG solid copper conductor should be sufficient to collect any ground currents circulating through the pool perimeter.

 

[don_resqcapt19]

I was not trying to say that the system needs to be part of the GES. I was just trying to show that the steel wire mesh is not located anywhere in the electrical code and just came out of left field. All other methods have some sort of place within the NEC in different places.

Why would it need to be in any other part of the code? This is a very specific rule for a specific purpose.

The oldest code on my computer is the 1999 and that includes reinforcing metal. Since they used the that term and not something that specifically indicates re-bar, I am including the welded wire mesh as reinforcing metal, as that is what it is and what it is used for when placed in concrete.

The conductivity of the metal is not the issue. The issue is the conductivity of the surface, and that is what triggered the requirement for a bonding grid, and not just a single bare conductor. The copper bonding grid is permitted to be 12" grids, but welded steel reinforcing mesh has a 6" grid. It probably does a better job than the 12" grid and we only need conductivity and not current carrying capacity.

 

[tortuga]

There was a Mike Holt video about how he went to someone’s house in NYC that was getting shocked by the pool. It was one of his videos in NEV (neutral earth voltage). Com Edison basically said we aren’t going to change anything and to solve this you need to provide better equipotential bonding.

That went on for a long time and I believe the homeowner sued and won in court, something like 2 million, its a budding area of law, "Electrical Trespass" or "stray voltage". they won because the utility did not have a 'easement' to run electric current thru their pool, thus the utility 'inversely condemned' the affected property, there were also other lawsuits from people without pools that just lived next to a substation.
I'd hate the be the attorney for the utility going up against Mike Holt as an expert witness.