Augment the supplement?
Augment the supplement?
read on to 250.53(D) and you will the water pipe ground must be supplemented: one perhaps two rods might be needed.
. . . 250.56 requires an installer, if using a ground rod to supplement the water, to augment the single rod with an additional electrode if it is not found to be 25 ohms or less. Hence the second rod.
250.53(D) does require the
supplemental electrode of a rod, pipe, or plate type to comply with 250.56.
250.56 specifies that the resistance of a
single electrode consisting of these types to have a resistance of 25 ohms or less to ground, or to be augmented by another.
Do you consider that a driven rod, which is supplementing the underground metal water pipe used as the main grounding electrode, is itself a
single electrode? :-? No matter the wording of 250.53(D), it does seem that the (first) electrode in 250.56 is not a "single electrode consisting of a rod, pipe, or plate" if bonded to a metal underground water pipe.
Your thoughts?