Per 250.190(B), when grounding a 5kV rated service disconnect operating at 4.16kV, what is the minimum size grounding electrode conductor for this service to connect the non-current metal parts of the metal-clad enclosure to ground? Assume the largest service-entrance phase conductor is 350kcmil and the equipment involved is fixed equipment.
Per this new section of the Code, the minimum size of the grounding electrode conductor is based on the size of the largest ungrounded phase conductor. A quick check of Table 250.66 reveals that a 350kcmil copper phase conductor requires a minimum size 2 AWG copper grounding electrode conductor.
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