Which conductor type must be present in each switch box or enclosure according to NEC requirements?

Which conductor type must be present in each switch box or enclosure according to NEC requirements?

• A. ungrounded
• B. designated
• C. grounded
• D. grounding

Answer: (C)

The main requirement here is that every switch box or enclosure must include an equipment grounding conductor. This grounding conductor—typically a bare copper or green wire—bonds the metal box and any devices to the building’s grounding system. Having this path provides a safe route for fault current, so if a hot conductor accidentally contacts the metal box, the fault current returns to the source and trips the overcurrent device, reducing the risk of shock. A neutral (grounded) conductor is not required in every box—many switch boxes only carry hot conductors—so the presence of a grounding conductor is the essential NEC requirement.

The main requirement here is that every switch box or enclosure must include an equipment grounding conductor. This grounding conductor—typically a bare copper or green wire—bonds the metal box and any devices to the building’s grounding system. Having this path provides a safe route for fault current, so if a hot conductor accidentally contacts the metal box, the fault current returns to the source and trips the overcurrent device, reducing the risk of shock. A neutral (grounded) conductor is not required in every box—many switch boxes only carry hot conductors—so the presence of a grounding conductor is the essential NEC requirement.