What is the purpose of bonding metal water piping to the grounding system?

• A. To increase water flow through pipes.
• B. To ensure a continuous bonding path that minimizes shock hazards and helps clear faults.
• C. To reduce corrosion of metal piping.
• D. To improve water heater efficiency.

Answer: (B)

Bonding metal water piping to the grounding system creates a continuous, low-impedance path for any fault current back to the source. This keeps the pipe at the same electrical potential as the rest of the grounding system, so if a hot conductor contacts the pipe, the fault current has a direct route to trip the protective device and shut off the fault quickly. It also reduces the chance that a person touching the pipe will encounter a dangerous potential difference. This bonding path helps ensure that faults are cleared and shock hazards are minimized.

Bonding is not about increasing water flow, reducing corrosion, or improving water heater efficiency, so those are not the purposes of tying the piping into the grounding system.