Final answer:
Grounding serves as a safety measure in electrical systems by establishing a conductor at zero volts through a low-resistance connection to the earth. It ensures that both the neutral wire and the appliance cases are safe to touch and provides an alternative current path in case of faults.
Step-by-step explanation:
Understanding Grounding in Electrical Systems
Grounding is a critical aspect of electrical safety and functionality in alternating-current (AC) systems. By creating a low-resistance path to earth, a conductor can be maintained at zero volts, ensuring safety and stability in the system. The three-wire grounding system typically involves a neutral wire, which is connected to the earth at both the voltage source and the user's location, effectively setting it to zero volts. This allows the neutral wire to act as a safe return path for current.
The inclusion of the third, or green ground wire, is for attaching to the case of an appliance, ensuring that the case is also at zero volts and thereby safe to touch. Furthermore, in the event of a short circuit, the grounding provides an alternative path for the current, preventing dangerous conditions like electrical shocks or fires. Circuit protection devices, such as fuses or circuit breakers, are placed in series on the live/hot wire to guard against thermal overload. It is essential to note that wire insulation colors can vary by region, necessitating the checking of local codes for proper identification.