Services & DistributionQuestion 7 of 521
A single ground rod is installed. Under what condition is a supplemental electrode NOT required?
a.The rod is 10 ft long
b.The rod is copper-clad
c.The rod's resistance to earth is 25 ohms or less
d.A GEC of 6 AWG is used
Explanation
Per 250.53(A)(2) Exception, a single rod, pipe, or plate electrode with a resistance to earth of 25 ohms or less needs no supplemental electrode. Rod length, cladding, and GEC size do not exempt the second-electrode requirement.
Law Reference: 2023 NEC §250.53(A)(2)Practice all 521 questions free — no signup required.
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