Which NEC section governs the main bonding jumper requirement between the grounding electrode conductors and the grounded conductor?

Which NEC section governs the main bonding jumper requirement between the grounding electrode conductors and the grounded conductor?

• A. NEC 250.24(B)
• B. NEC 230.70(A)(1)
• C. NEC 300.5(D)(4)
• D. NEC 250.94(A)

Answer: (A)

The main bonding jumper is the connection that ties the grounded conductor (neutral) to the grounding electrode system at the service equipment, creating a single reference point for the electrical system. NEC 250.24(B) specifically covers bonding the grounded conductor to the grounding electrode conductor, which is the requirement for the main bonding jumper. This bond ensures that all grounding electrodes and the neutral sit at the same potential, which helps fault current return properly and prevents dangerous voltage differences on metal parts. Other sections address different topics—service disconnect location, how conductors areRun, or general bonding or equipment grounding rules in other contexts—so they don’t establish the specific neutral-to-ground bonding at the service equipment.

The main bonding jumper is the connection that ties the grounded conductor (neutral) to the grounding electrode system at the service equipment, creating a single reference point for the electrical system. NEC 250.24(B) specifically covers bonding the grounded conductor to the grounding electrode conductor, which is the requirement for the main bonding jumper. This bond ensures that all grounding electrodes and the neutral sit at the same potential, which helps fault current return properly and prevents dangerous voltage differences on metal parts.

Other sections address different topics—service disconnect location, how conductors areRun, or general bonding or equipment grounding rules in other contexts—so they don’t establish the specific neutral-to-ground bonding at the service equipment.