Services, Grounding & BondingQuestion 46 of 120
Where two rod electrodes are installed to make up the grounding electrode system, what is the minimum spacing between them?
a.3 feet
b.6 feet
c.8 feet
d.10 feet
Explanation
Rods that supplement one another must be separated by at least 6 feet so their earth shells do not overlap and defeat the purpose of the second rod. The 8-foot figure is the minimum rod length rather than spacing, and 3 or 10 feet are not the code minimum.
Law Reference: 2023 NEC §250.53(A)(3)Practice all 120 questions free — no signup required.
Related questions on this topic
- A 45 kVA, three-phase transformer has a 480-volt primary. If only primary overcurrent protection is provided at 125 percent, what is the maximum standard primary device rating?
- What is the secondary full-load current of a 75 kVA transformer with a 208Y/120-volt, three-phase secondary?
- What is the minimum length of a rod-type grounding electrode?
- A single ground rod does not have to be supplemented by a second electrode if its resistance to earth does not exceed what value?
- A metal underground water pipe qualifies as a grounding electrode only if it is in direct contact with the earth for at least what length?
- A concrete-encased electrode may be formed by at least 20 feet of which of the following?
Last reviewed: · editorial process
PrepPass Editorial Team · Verified against Journeyman Electrician Licensing Exam (NEC-based) · How we review