What should be removed from a sub-panel to ensure proper operation?

Removing the bonding screw from a sub-panel is essential for ensuring proper operation because the bonding screw connects the neutral bus bar to the metal chassis of the panel. In a sub-panel, the neutral and ground conductors must be kept separate to prevent parallel paths for return current, which can create safety hazards.

In the main service panel, the bonding of the neutral to ground is necessary for safety. However, in a sub-panel, this bonding creates issues because if a fault occurs, it could potentially allow neutral current to flow on the grounding wire, which could lead to an electric shock hazard or fire risk. Therefore, by removing the bonding screw in a sub-panel, you maintain the separation of grounds and neutrals, ensuring compliance with electrical codes and enhancing safety.

Understanding this concept is critical for electrical safety practices and is a core principle within electrical installations.