Which of the following statements is true regarding bonding of lightning protection ground terminals?

• A. They must be bonded to the building grounding electrode system
• B. They should be isolated from the building grounding electrode system
• C. They must be connected to the neutral conductor
• D. They must be connected to the equipment grounding conductor

Answer: (A)

Bonding the lightning protection ground terminals to the building’s grounding electrode system creates a single, low-impedance earth reference for the entire structure. This ensures that during a lightning strike, the current has a direct path to earth and all metal parts share the same potential, reducing the risk of dangerous voltage differences, arcing, or side flashes that could injure people or damage equipment. Isolating the lightning protection system from the grounding electrode system would leave it floating at a high potential relative to the building, defeating the safety purpose. Connecting to the neutral is inappropriate because the neutral is not a dedicated grounding path for lightning currents, and tying the LPS to it elsewhere in the system could create hazardous conditions. While the equipment grounding conductor is part of the overall grounding network, the essential requirement is integration with the building’s grounding electrode system to maintain a common earth reference.