When bonding metal water piping systems, to what can they be connected?

When bonding metal water piping systems, connecting them to the service equipment enclosure is considered appropriate and effective. This connection ensures that the water piping system has a low-resistance path to ground, which helps enhance safety by reducing the risk of electric shock due to fault conditions.

The service equipment enclosure typically houses the main electrical panel, and by bonding the piping system to this enclosure, any fault currents can flow safely to the ground, mitigating the risks associated with unintentional current flowing through the water pipes. This is in line with current electrical codes and standards that aim to ensure a safe electrical system grounding.

While grounding conductors, nearby metallic objects, and dedicated ground wires could seem reasonable, they may not directly provide the level of safety and continuity achieved through the bond to the service equipment enclosure. Proper bonding directly links the piping system to the main grounding system of the building, creating a more effective electrical safety solution.