What kind of electrical fault does a GFCI protect against?

A GFCI, or Ground Fault Circuit Interrupter, is specifically designed to protect against ground faults. A ground fault occurs when there is an unintended path for electrical current to flow to the ground, which can happen if a person accidentally contacts a live wire or if moisture creates a conductive path. This scenario is particularly dangerous as it can lead to electric shock or electrocution.

The functionality of a GFCI is based on the detection of imbalance between the outgoing and incoming current. If it senses that the current flowing through the circuit is not equal—indicating that some of it has found an unintended path to ground—it will quickly disconnect the power to prevent potential harm.

Other types of electrical faults, such as overload or short circuit faults, are addressed by different protective devices like circuit breakers or fuses, which are designed to interrupt the circuit when excess current flows, rather than specifically monitoring for ground faults. Surge faults, often caused by transient voltage spikes, are commonly mitigated by surge protectors but do not fall within the protective capabilities of a GFCI. Therefore, a GFCI plays a critical role in safety by specifically targeting ground fault conditions.