In a subpanel, what is the recommended approach regarding the bonding jumper between neutral and ground bars?

• A. A bonding jumper must be installed between neutral and ground bars
• B. A bonding jumper must not be installed between neutral and ground bars
• C. The neutral bar must be removed entirely from the subpanel
• D. Both bars must be bonded to the enclosure

Answer: (B)

The main concept here is isolation of neutral and grounding paths in a subpanel. In a subpanel, neutral and grounding conductors must stay separate from each other and from the enclosure. A bonding jumper between the neutral and ground bars would effectively re-bond neutral to ground inside the subpanel, creating a current path on the grounding conductor and defeating the purpose of isolation. This can cause stray currents on the grounding system, interferes with protective devices, and compromises fault clearance.

Therefore, the recommended approach is not to bond neutral to ground in the subpanel. Instead, bond the ground bar to the enclosure and connect all equipment grounding conductors to that bar. The neutral bar remains isolated from the enclosure. The neutral and ground bonding only occurs at the main service disconnect, not in subpanels.

The other options aren’t appropriate because they either reintroduce a neutral-ground bond in the subpanel, remove the neutral bar entirely, or bond both bars to the enclosure, which would again create a neutral-to-ground bond within the subpanel.