If a cable has any metallic components at termination point, what does the NEC require?

If a cable has any metallic components at termination point, what does the NEC require?

• A. grounding IAW NEC 250
• B. insulation only
• C. no special requirement
• D. bond to neutral conductor

Answer: (A)

When there are metallic parts at the termination point of a cable, the safety rule is to bond those parts to the equipment grounding conductor in accordance with NEC Article 250. This creates a low-impedance path for any fault current to return to the source, which makes the overcurrent device trip quickly and keeps metal surfaces at ground potential, reducing the shock risk to anyone touching the cable or device. Insulation alone cannot protect against shock if a fault energizes the metal components, and saying no special requirement would ignore the hazard. Bonding to the neutral conductor is not allowed in normal branch-circuit practice (neutral-to-ground bonding is only at the service equipment), so that option isn’t appropriate. Bonding metal parts to the grounding system ensures a reliable path for fault current and proper operation of protective devices.

When there are metallic parts at the termination point of a cable, the safety rule is to bond those parts to the equipment grounding conductor in accordance with NEC Article 250. This creates a low-impedance path for any fault current to return to the source, which makes the overcurrent device trip quickly and keeps metal surfaces at ground potential, reducing the shock risk to anyone touching the cable or device.

Insulation alone cannot protect against shock if a fault energizes the metal components, and saying no special requirement would ignore the hazard. Bonding to the neutral conductor is not allowed in normal branch-circuit practice (neutral-to-ground bonding is only at the service equipment), so that option isn’t appropriate. Bonding metal parts to the grounding system ensures a reliable path for fault current and proper operation of protective devices.