Which statement best describes the difference between grounding and bonding in electrical systems?

• A. Grounding is the same as bonding.
• B. Grounding provides a reference potential and fault path; bonding keeps conductive parts at the same potential.
• C. Bonding provides a reference potential and fault path; grounding keeps conductive parts at the same potential.
• D. Grounding provides a reference potential and fault path; bonding is unnecessary in most systems.

Answer: (D)

Grounding and bonding serve two different safety roles in electrical systems. Grounding provides a reference point for the system voltage and a low-impedance path for fault current to reach earth, which helps protective devices detect faults and keeps voltages stable during normal and fault conditions. Bonding connects all exposed, normally non-current-carrying metal parts—like enclosures, conduits, and equipment frames—to that same grounding system so they stay at the same electrical potential. This prevents dangerous voltage differences that could shock someone who touches different metal parts.

In practice, both are used together. Grounding gives the fault path and system reference, while bonding eliminates potential differences between conductive parts. Saying bonding is unnecessary in most systems isn’t accurate; bonding is a standard safety requirement in many installations to reduce shock hazards.