Distinguish between equipotential bonding and protective bonding.

• A. Protective bonding ties exposed conductive parts to protective earth only
• B. Equipotential bonding ties exposed conductive parts to a common potential; protective bonding connects exposed conductive parts to the protective earth to guarantee fault clearance.
• C. Equipotential bonding ties to neutral
• D. Both terms mean the same thing

Answer: (B)

The important idea is how each bonding type handles potential differences and fault currents. Equipotential bonding aims to keep exposed conductive parts and other conductive items at the same electrical potential, by linking them with bonding conductors so there’s no significant voltage difference between metalwork that a person might touch. This reduces the chance of a shock if one part becomes energised or if two parts could be touched simultaneously.

Protective bonding, on the other hand, is about providing a low-impedance path to earth for fault currents. By tying exposed conductive parts to the protective earth conductor, any fault current has a clear route to earth, which causes protective devices (like fuses or breakers) to operate and disconnect the supply, ensuring fault clearance and safety.

So equipotential bonding focuses on preventing hazardous voltage differences between conductive parts, while protective bonding ensures faults are cleared quickly by delivering current to earth. The statement that equipotential bonding ties exposed conductive parts to a common potential and protective bonding connects exposed conductive parts to the protective earth to guarantee fault clearance expresses that distinction accurately.