What is the purpose of grounding rods and bonding jumpers in a distribution system?

• A. Ground rods create a reference to earth.
• B. Bonding jumpers ensure all metallic parts are at the same potential.
• C. Ground rods store energy for fault currents.
• D. Ground rods and bonding jumpers ensure all metallic parts are at the same potential and provide a stable ground reference.

Answer: (D)

The key idea is to keep all metal parts at the same electrical potential and provide a solid path for fault current to return to the source. Grounding rods give the system a reference to the earth and help dissipate fault energy into the soil, but the earth alone is not a reliable low-impedance return path. Bonding jumpers connect all metallic components—enclosures, conduits, structural steel, water piping, and other equipment—to the grounding system so they share the same potential. This minimizes dangerous voltage differences, reduces touch and step hazards, and ensures fault currents have a clear, low-impedance path back to the source. When both grounding and bonding are used, you get a stable ground reference and effective fault clearance, which is why this combined purpose is the best description.