What gauge conductor should be used to bond each leg of a self-supporting tower?

• A. #6 AWG
• B. #2 AWG
• C. #4 AWG
• D. #1 AWG

Answer: (B)

Equipotential bonding of a self-supporting tower requires a low-impedance path that ties each leg to a common grounding point so that metal parts stay at the same electrical potential during faults or lightning. Using a 2 AWG copper bonding conductor from each leg to the base ground point provides a robust, low-resistance path that can carry any fault or lightning-induced current and keep the legs at nearly the same potential. This minimizes voltage differences between legs, reduces arcing risk, and protects equipment.

Smaller gauges would have higher impedance and may not reliably carry fault currents or lightning surges, leading to potential differences between legs. Larger gauges are more than necessary for this application and add cost without added benefit in typical scenarios.