At service equipment, what is the purpose of the main bonding jumper?
- AIt replaces the grounding electrode conductor
- It bonds the service neutral to grounding components
- CIt isolates the service enclosure from ground
- DIt carries normal neutral current to every downstream enclosure
Why B is correct
The main bonding jumper establishes the service bonding connection and the low-impedance fault-current path. Downstream enclosures normally remain isolated from the neutral, and the jumper does not eliminate the grounding electrode conductor.