What is the purpose of an equipment grounding conductor (EGC)?

• A. To carry normal current
• B. To connect the equipment to the neutral conductor
• C. To shield against EMI
• D. To provide a low-impedance path to ground for fault currents and to enable overcurrent protection devices to operate

Answer: (D)

An equipment grounding conductor is there to give fault current a low-impedance route to earth, so any fault that makes metal parts live will drive enough current back to the source to trip the overcurrent protection promptly. This keeps exposed surfaces close to earth potential and reduces the chance of shock if a fault occurs. In normal operation it doesn’t carry load current; it’s not used to connect equipment to neutral, and it isn’t for EMI shielding. Grounding conductors are typically bare or green-insulated copper (or metallic conduits) that bond equipment and enclosures to the building’s grounding system, ensuring a reliable path for fault current to trip protective devices quickly.