Where the supplemental electrode is a rod, that portion of the bonding jumper that is the sole connection to the supplemental grounding electrode shall not be required to be larger than _____ AWG copper wire.

• A. 4
• B. 6
• C. 8
• D. 10

Answer: (B)

When a supplemental grounding electrode is used, the bond to that electrode doesn’t need to be as large as the main bonding path. If the supplemental electrode is a rod, the portion of the bonding jumper that is the sole connection to that rod is allowed to be up to six AWG copper. This recognizes that the rod serves as an auxiliary path to earth and isn’t the primary fault-current return path—the heavy current still flows through the main grounding electrode system and associated conductors. So the largest size permitted for that segment is six AWG copper, with smaller sizes (like eight or ten AWG) also acceptable for that connection.