What is the purpose of a ground wire in an electrical system?

• A. Provide a path to earth to dissipate fault current
• B. Carry normal operating current
• C. Serve as a neutral conductor
• D. Increase system voltage

Answer: (A)

Grounding gives exposed metal parts a safe, low-impedance path to the earth. When a fault occurs—like a live wire touching a metal enclosure—the fault current can flow through the ground wire to the earth, creating enough current to trip the overcurrent protective device (fuse or breaker) quickly. This protects people from shock and helps equipment stay safe by preventing sustained fault conditions. The ground wire also helps keep metal parts at earth potential, reducing potential differences that could cause shocks.

Normal operating current travels through the circuit’s insulated conductors, not through the ground conductor. The neutral conductor is a separate return path for current during normal operation, and while it is bonded to earth at the main service, grounding conductors and neutral conductors are not the same thing. Grounding does not serve to carry normal current or to raise system voltage; its purpose is safety and fault current return to allow fast fault clearing.