Final answer:
Bonding copper water pipes forms a low-impedance path to the voltage source to assist in triggering a circuit breaker. The purpose is to instantly disconnect power in the event of a fault, thereby preventing electric shock or thermal hazards.
Step-by-step explanation:
Bonding the copper water pipes in a house provides a low-impedance fault current path back to the source of the voltage to facilitate the tripping of a breaker. This is crucial for preventing potential electrical hazards. When a fault occurs, such as a wire that allows contact with the case of an appliance, the bonding and grounding system ensures that the fault current has a path to flow towards the earth, which helps in the immediate tripping of the circuit breaker or activation of a ground fault interrupter (GFI). With an intact ground connection, the flow of fault current through the bonding system causes a significant enough difference in the currents in the live/hot and neutral wires, prompting the GFI to trip swiftly and immediately cut off the power supply, thereby reducing the risk of electric shock or thermal overload.
The three-wire system plays a vital role in electrical safety. It connects the neutral wire to the earth at the voltage source, ensuring it is at zero volts and provides an alternative return path for the current through the earth. The system includes the live/hot, neutral, and earth/ground wires, and both the neutral wire and the case of the appliance are grounded, with zero potential to earth.