What happens when a GFI detects a ground current fault?

When a Ground Fault Interrupter (GFI) detects a ground current fault, it shuts down the circuit to prevent electric shock hazards. The primary function of a GFI is to continuously monitor the amount of current flowing to and from a specific electrical device. If it senses an imbalance, indicating that some of the current is leaking to the ground—commonly due to faulty wiring or contact with water—the GFI quickly interrupts the flow of electricity. This action is crucial because ground faults can lead to serious injuries, including electric shocks that may be fatal.

The other options suggest actions that are contrary to the safety measures a GFI is designed to implement. For instance, increasing voltage output would exacerbate the danger, while keeping the circuit active in the presence of a fault would also increase the risk of shock. Sending an alert signal, while potentially helpful in some contexts, is not the primary function of a GFI in immediate fault situations. Its most critical response is to shut down the circuit promptly to ensure safety.