2011: Pool Grounding Grid - 07/05/09 11:26 PM
I see there are numerous proposals to change the requirements for the equipotential grid around pools. I daresay that few sections of the NEC have undergone a more furious amount of revision than 680.26 has in the last few cycles.
Some of the proposals seek to remove the requirement; others try to make it more specific. There is one proposal (17-172) which, while it addresses the shell rather than the deck surfaces, causes me some concern; IMO, it's one of those things that will take on a life of it's own, and greatly increase pool costs.
Also, IMO, none of these proposals address inaccessible surfaces.
My own research into this topic points to this entire issue arising solely from the advent of ONE type of pool - the shipped complete by truck, blow molded plastic pool shell. Another possible contender is the plastic encapsulated metal pool shell. In either instance, the real culprit seems to be the inadvertant insualting of the pool water from the surrounding grade. It appears to me that this is an issue better addressed by identifying those particular methods, rather than trying for a 'one size fits all' approach.
Some of the proposals seek to remove the requirement; others try to make it more specific. There is one proposal (17-172) which, while it addresses the shell rather than the deck surfaces, causes me some concern; IMO, it's one of those things that will take on a life of it's own, and greatly increase pool costs.
Also, IMO, none of these proposals address inaccessible surfaces.
My own research into this topic points to this entire issue arising solely from the advent of ONE type of pool - the shipped complete by truck, blow molded plastic pool shell. Another possible contender is the plastic encapsulated metal pool shell. In either instance, the real culprit seems to be the inadvertant insualting of the pool water from the surrounding grade. It appears to me that this is an issue better addressed by identifying those particular methods, rather than trying for a 'one size fits all' approach.