Service raceways threaded into metal service equipment such as bosses (hubs) are considered to be effectively _____ to the service metal enclosure.

• A. Bonded
• B. Grounded
• C. Connected
• D. Insulated

Answer: (A)

Bonding is the intentional electrical connection that keeps metal parts at the same potential and provides a low-impedance path for fault currents. When a service raceway is threaded into metal service equipment bosses, the metal-to-metal contact creates a direct conductive path that ties the raceway to the service enclosure. This makes the raceway effectively bonded to the enclosure, so it shares the same electrical potential and contributes to the system’s fault-current path. It isn’t the same as grounding to earth, which involves the grounding electrode system; it’s about maintaining continuity among metallic parts. It isn’t insulated, and simply saying it’s connected doesn’t emphasize the continuous, low-resistance bond.