In a residential installation, how should the grounding terminal and neutral bar of a subpanel be configured?

In a residential installation, the grounding terminal and neutral bar of a subpanel should indeed be configured with the neutral isolated from the ground and only the grounding terminal bonded to the enclosure. This is critical for several reasons.

The primary purpose of separating the neutral and ground at the subpanel is to prevent parallel paths for neutral current. If the neutral is bonded to the ground in a subpanel, neutral return current could flow on the grounding system, which poses safety risks such as creating a shock hazard. It can also lead to electromagnetic interference and can damage sensitive electronics.

By isolating the neutral, it ensures that the return current only flows through the neutral conductor back to the main panel, where it is properly bonded. The grounding terminal, on the other hand, provides a safety path for current in the event of a fault condition, helping to trip breakers and clear faults effectively.

Moreover, the grounding terminal must be bonded to the panel enclosure to create a direct path to ground. This bonding helps in the case of fault current, ensuring that the panel itself does not become energized.

Overall, this configuration enhances safety and compliance with electrical codes, ensuring the system operates correctly and minimizes hazards.