Which statement about building-entry bonding is correct?

• A. Bonding should be as close as practical to the entry, using an EGB or grounding electrode system.
• B. Bonding should be far from the entry to minimize interference.
• C. Bonding should occur only at the tower base.
• D. No bonding is required at the entry.

Answer: (A)

Bonding at the entry creates a single, low-impedance path to earth where all equipment and the building ground meet. By tying the building’s entrance ground to an EGB or grounding-electrode system as close as practical to the entry, you establish a common potential for the equipment grounding conductor and the building ground right where cables and conduits enter. This minimizes potential differences during faults or surges, reduces the chance of energized enclosures or touch/step hazards, and helps limit interference by keeping the grounds at a consistent level.

Bonding farther from the entry would leave separate ground paths that can drift in potential relative to each other, increasing the risk of voltage differences and related safety and interference issues. Bonding only at the tower base or not bonding at all neither addresses the ground at the building entry nor ensures a unified equipotential path for the indoor equipment and entry conduits. Using the grounding electrode system or the EGB at the entry provides the proper, low-impedance reference point for the entire site.