to be honest Virgil
i can rarely cut 250.53(G), save for an 'oblique' angle myself.... (puff...puff..pant...) aw, just throw 'em in the ditch...
well, the NEC does not quite
come out and say it, but 250.52(A)(3)sounds Uferish
it almost sounds as if the 1-7 are in order of preference....
250.50 Grounding Electrode System.
If available on the premises at each building or structure served, each item in 250.52(A)(1) through (A)(6) shall be bonded together to form the grounding electrode system. Where none of these electrodes are available, one or more of the electrodes specified in 250.52(A)(4) through (A)(7) shall be installed and used.
Formal Interpretation 78-4
Reference: Article 250.50
Question: Is it the intent of 250.50 that reinforcing steel, if used in a building footing, must be made available for grounding?
Issue Edition: 1978
Issue Date: March 1980
right... ever try convincing the concrete dudes? i just did a ufer last month, & was dubbed loco sparky'
now the poco engineers recognize the efficy , seems the linecrew traditionally look for rods..... i guess you'll need to talk to the poco boss..
sometimes a 250.52(A)(4) "ground ring" is spec'd out by architects. i just don't know how to 'encircle' a structure with only 20' though...
Am I right to assume that ground rods are practically useless in these soil conditions?
comparitively i'd vote yes, useless...
i'm sure there's a Soares ditty about the efficy of 'made' electrodes, i've heard of some who drive excessive depths
and/or distances apart to achieve a decent ohmic value.
I also heard the IAEI did a study....
[This message has been edited due to blistered fingers}
[This message has been edited by sparky (edited 10-01-2002).]