Which section mandates the bonding of metal water piping systems installed within buildings?

The correct answer is based on the requirements set forth in Section 250.104 of the National Electrical Code (NEC). This section specifically addresses the bonding of metal water piping systems, emphasizing the need for bonding where these systems are installed within buildings to ensure electrical safety and mitigate shock hazards.

Bonding these metallic water pipes helps maintain a equipped grounding path and limits voltage differences that could pose a risk of electrical shock. This is especially critical in conditions where metal pipes could become energized due to faults or other electrical issues. Ensuring that these systems are bonded creates a pathway for fault current to safely return to the ground, reducing the potential for electrical hazards.

Understanding the context of bonding in water piping systems is essential in electrical installations, as it integrates the water piping into the broader ground fault protection strategy, enhancing overall safety within residential and commercial buildings.