What must SPDs protecting communications systems be grounded and bonded to?

Grounding and bonding surge protective devices (SPDs) that protect communications systems is critical for ensuring effectiveness in mitigating the risk of lightning and surges. The correct answer emphasizes the importance of connecting SPDs to the same grounding system used for the electric service in the building.

This connection ensures that all systems operate from a common reference point, helping to prevent potential differences that could lead to damaging surge voltages. By grounding and bonding the SPDs to the electric service's grounding point, it enhances the system’s ability to channel surge currents safely to the ground without causing harm to the communication equipment or other electrical systems. This method also complies with industry standards and electrical codes, which mandate such practices for safety and reliability.

The other suggested grounding options, such as grounding SPDs to a water pipe or a facility's lightning rod, may not provide the same level of safety or code compliance. These alternatives may not adequately ensure the necessary low-impedance path to ground, which is essential for the effective operation of SPDs. Similarly, using any available grounding source could lead to inconsistent protection levels and compromises in safety, as different grounding systems may not be bonded together or might have different potentials. Thus, grounding SPDs to the electric service's grounding point is both