If anything else, the depth and detail of the responses are worth reading in the IAEI BB. Many lead me to investigate the current ROP's , where said issues may be in the process of being addressed. This is testimonial to the 'chat level' there, so i understand why it's a 'take no prisoners' room.
So Virgil,
I've been struggling with 250 for some time, ask a lot of Q's, that's all. what's 'voltage gradient', i suppose the term implies that stray voltage could not exist in different readings given the amount of bonding.
note the same term is applied to pools in 680-22 and the intent of it being an isolated entity.
Consider also the theory, in that only energized equipment can constitute a return path, the point being that the bonding of such items, and/or it's direct line of sight back to the power source would be what is most pertinent to bond. Note rop # 3720 mentions Mich State U as having done studies on the topic, that would be good info if we could access it.
The pad being poured, i would simply make the best of the situation here. There is no harm in running a #2cu around the pad, loop it thru as many G-rods as you can, maybe a bag or 2 of bentonite, and hit at least all 4 corners of the pad's rebar via J-hammer at points where the sill plate will hide the damage. Note the article does not go into detail on HOW this bonding is done....
Note 250-32(e) is for a reason, probably to exclude any opportunity for parrallel paths.
hope this helps, maybe others will comment on the fix for this, i call this the NEC's "field of dreams" mentality, assuming other trades ( or manufacturers)will acknowledge their wishes.
It would seem this requirement would be just as easy as requiring cows to sing the national anthem on sunrise..
have you ever said "equpotential plane" to a farmer? most would probably tell you to land it elsewhere....
[This message has been edited by sparky (edited 05-24-2001).]