Name common grounding electrodes used in homes.

• A. Copper wire, plastic conduit, glass insulation, and wooden studs.
• B. Aluminum wiring, stainless steel, PVC piping, fiberglass.
• C. Grounding is done by the circuit breaker alone.
• D. Ground rods, metal water piping, concrete-encased electrodes, and building steel.

Answer: (D)

Grounding electrodes are metal items that provide a real path to earth and establish a stable reference for fault currents in a home’s electrical system. The common ones used are ground rods driven into the soil, the metal water service piping, a concrete-encased electrode (the Ufer electrode) embedded in the building foundation, and building steel. These are specifically recognized as grounding electrodes by the NEC and must be bonded to the grounding electrode conductor that connects to the main service equipment. Nonconductive items like plastic conduit, glass insulation, wooden studs, or fiberglass don’t serve as grounding electrodes, and materials like copper wire aren’t electrodes by themselves. Also, grounding isn’t accomplished by the circuit breaker alone—the breaker protects, but the grounding path to earth comes from these electrodes and their proper bonding.