What is the function of a ground fault circuit interrupter (GFCI)?

The ground fault circuit interrupter (GFCI) is specifically designed to enhance safety in electrical systems by cutting off power when it detects an imbalance in the electrical current. This imbalance typically indicates that some of the current is finding an unintended path to ground, which may occur in situations like a person accidentally touching a live wire or a faulty appliance. The GFCI continuously monitors the incoming and outgoing current and can react within milliseconds to stop the flow of electricity, thereby reducing the risk of electric shock and potentially preventing severe injury or fatality.

This protective function is crucial in wet areas such as kitchens, bathrooms, and outdoor settings where the risk of shock is heightened. It is distinct from devices that merely switch circuits on and off, prevent electrical fires through circuit protection, or monitor load, each of which serves different safety and operational purposes in electrical systems.