Final answer:
The text explains the three-wire system used to ensure electrical safety in household wiring, consisting of zero volt grounded neutral and appliance casing, and a live/hot wire supplying power. Proper coloring coding for wire insulation is vital for safety, and colors can vary by region.
Step-by-step explanation:
The passage describes an electrical safety feature known as the three-wire system used in household wiring. This system includes a neutral wire, which is grounded at two points to create a zero-volt reference and provide a return path for current. Additionally, there is a safety mechanism in place, which connects the appliance casing to the ground through a green wire, ensuring that the casing is also at zero volts to prevent electric shocks. The live/hot wire is responsible for supplying the voltage and current required by appliances. When properly implemented, this system facilitates the tripping of a circuit breaker in case the live/hot wire comes into contact with the appliance case, due to worn insulation or other faults, thus preventing potential electric shocks and forcing a repair of the appliance, as depicted in Figure 23.32.
The importance of coloring coding for wire insulation is mentioned, with the reminder that these colors can vary by region, and it is critical to verify local codes and standards to ensure proper and safe electrical installations.