What is the role of ground-fault circuit interrupters in electrical systems?

Ground-fault circuit interrupters (GFCIs) play a crucial role in enhancing safety within electrical systems, specifically by preventing electrical shocks. They achieve this by detecting imbalances in electrical current — for example, when the current flowing through a circuit deviates from the intended path, such as when it flows through a person. Upon sensing this imbalance, a GFCI interrupts the circuit almost instantaneously, significantly reducing the risk of shock or electrocution.

To provide a clearer context, consider the functions not chosen. Enhancing power supply is generally related to increasing efficiency or capacity, which is not the function of a GFCI. Protection from overloads usually involves circuit breakers or fuses that monitor current flow and cut off power if it exceeds safe levels. As for voltage regulation, that function is performed by devices like voltage regulators and transformers, not GFCIs. Thus, the primary and most critical role of GFCIs is indeed to prevent electrical shocks, ensuring a safer environment for users when working with or around electrical installations.