Journeyman Electrician Exam (NEC)Grounding and BondingEasy
A residential electrician is installing a new 200-ampere service. What is the minimum size copper grounding electrode conductor required for a driven ground rod, according to NEC® 250.66(A)?
- ANo. 2 AWG
- BNo. 4 AWG
- CNo. 8 AWG
- DNo. 6 AWG
Show answer & explanationAnswer & explanation
Correct answer: D. No. 6 AWG
NEC® 250.66(A) specifies that a grounding electrode conductor for a rod, pipe, or plate electrode shall not be required to be larger than No. 6 AWG copper. The service size does not affect this minimum for driven rods.
Why the other options are wrong
- A. No. 2 AWG is significantly larger than the minimum required and would be acceptable but not the minimum.
- B. No. 4 AWG is larger than the minimum required and would be acceptable but not the minimum.
- C. No. 8 AWG is permitted for concrete-encased electrodes, but not typically for driven rods as a minimum.
Grounding Electrode Conductor Sizing (Driven Rods)
The minimum size for a copper grounding electrode conductor connected to a driven ground rod is No. 6 AWG, regardless of the service size, as per NEC® 250.66(A).
- Applies to rod, pipe, and plate electrodes.
- Minimum size is No. 6 AWG copper.
- Service size does not increase this minimum for these specific electrodes.
Memory trick: Six Gauge for Sticks and Plates, no matter the Amps.