What is the purpose of a bonding jumper?

• A. To join two circuits in series to share current.
• B. To increase the impedance of the grounding path.
• C. To connect metal parts to create a continuous path for grounding and reduce potential differences.
• D. To indicate a fault with an audible alarm.

Answer: (C)

Bonding jumpers create a low-impedance connection that ties metal parts together so they are at the same electrical potential. This equipotential bonding keeps conductive surfaces at a common voltage, which minimizes dangerous voltage differences if a fault occurs and ensures any fault current has a clear path to the grounding system. That way, the protective device can operate quickly to disconnect the fault and reduce shock risk. In practice, bonding jumpers are used to connect metal water or gas piping, equipment enclosures, and structural metal to the building grounding system so these metal parts don’t develop dangerous potential differences relative to one another.

This isn’t about putting circuits in series or increasing the impedance of the grounding path, and it isn’t about signaling a fault with an alarm.