In a typical electrical system, where should the neutral be bonded to ground?

In a typical electrical system, where should the neutral be bonded to ground?

• A. At the service disconnect or main service equipment
• B. At the branch circuit panel in each room
• C. At the transformer substation
• D. At the grounding electrode conductor near the water pipe

Answer: (A)

Bonding the neutral to ground should happen at the service equipment—the main service disconnect. This creates a single, well-defined earth reference for the entire installation and provides a low-impedance path for fault current back to the source. With this one-point bond, fault currents trip the overcurrent protective device quickly, keeping the system safe. If the bond were made elsewhere—at branch panels, at the transformer substation, or at a grounding electrode near a water pipe—multiple bonding points would appear, causing neutral currents to flow on grounding conductors, energizing metal parts, and creating safety risks and nuisance currents. The grounding electrode system is connected to this bond to establish earth reference, but no additional neutral-to-ground bonds are desired beyond the main service equipment.

Bonding the neutral to ground should happen at the service equipment—the main service disconnect. This creates a single, well-defined earth reference for the entire installation and provides a low-impedance path for fault current back to the source. With this one-point bond, fault currents trip the overcurrent protective device quickly, keeping the system safe. If the bond were made elsewhere—at branch panels, at the transformer substation, or at a grounding electrode near a water pipe—multiple bonding points would appear, causing neutral currents to flow on grounding conductors, energizing metal parts, and creating safety risks and nuisance currents. The grounding electrode system is connected to this bond to establish earth reference, but no additional neutral-to-ground bonds are desired beyond the main service equipment.