NEC Commercial Electrical Practice Test

What is the minimum size of copper wire required for the bonding jumper to a rod, pipe, or plate supplemental electrode?

1. 4 awg copper

2. 6 awg copper

3. 8 awg copper

4. 10 awg copper

The correct answer is: 6 awg copper

The minimum size of copper wire required for the bonding jumper to a rod, pipe, or plate supplemental electrode is indeed 6 AWG. This requirement is established in the National Electrical Code (NEC), which aims to ensure adequate grounding and bonding for electrical safety. Specifically, 6 AWG copper wire is used for bonding jumpers because it provides a sufficient current-carrying capacity and strength to handle fault currents while maintaining effective conductivity. This size also helps to minimize the voltage drop during abnormal conditions, which is essential in protecting equipment and ensuring safety for personnel. Larger sizes, such as 4 AWG, may be used in certain scenarios, but the minimum specified size for general applications regarding bonding jumpers is 6 AWG. Smaller sizes, like 8 AWG or 10 AWG, do not meet the necessary conductivity and current-carrying standards required for effectively connecting to supplemental electrodes. By adhering to the NEC guidelines, practitioners can reduce risks associated with electrical faults and improve the overall safety of the electrical system.