What is the purpose of bonding continuity testing during commissioning?

• A. To confirm color codes
• B. To verify bonding continuity ensures a low impedance path to earth
• C. To measure insulation resistance
• D. To ensure the building's lighting circuits operate

Answer: (B)

Bonding continuity testing checks that every protective bonding conductor and exposed conductive part is connected to the earth return network with a continuous, low impedance path. This guarantees that, if a fault makes a metal part live, the fault current has a ready path to earth and the protective device will trip quickly, keeping touch voltages at a safe level. In other words, it verifies the safety earth network is intact and capable of carrying fault current without resistance that’s high enough to prevent rapid disconnection. Color codes, insulation resistance tests, and verifying lighting operation are separate checks that serve different safety and performance purposes.