What is the purpose of a GFCI (Ground Fault Circuit Interrupter)?

The purpose of a GFCI (Ground Fault Circuit Interrupter) is to prevent electric shock by interrupting power to a circuit when a fault is detected. This device monitors the current flowing in a circuit and compares the outgoing current with the returning current. If there is an imbalance, which may indicate that some current is leaking to the ground (potentially through a person's body), the GFCI reacts quickly—typically within milliseconds—to cut off the electrical supply.

This protective measure is crucial in environments where there is a higher risk of electric shock, such as bathrooms, kitchens, and outdoor areas where moisture is present. By doing so, GFCIs significantly enhance safety for users and help to prevent accidents related to electrical shock, especially in wet or damp situations.