Which of the following describes the operation of a GFI breaker when it detects a fault?

The operation of a Ground Fault Interrupter (GFI) breaker is centered around its ability to protect against electrical shock by detecting ground faults. When a GFI breaker senses an imbalance in the electrical current—specifically when it detects that the current returning through the neutral wire does not match the current flowing through the hot wire—it interprets this discrepancy as a potential fault. The threshold for this imbalance is typically set at 5 mA (milliamperes). When this threshold is exceeded, indicating a fault condition, the GFI trips and interrupts the circuit to prevent electric shock and potential harm.

This characteristic is crucial for enhancing safety in environments where water is present or where there is an increased risk of electrical shock, such as kitchens, bathrooms, and outdoor installations. The GFI breaker effectively reduces the risk of injury by acting quickly in response to detecting even small amounts of leakage current. Consequently, the specific nature of this operation, where the breaker trips if the difference exceeds 5 mA, aligns perfectly with the core function of a GFI breaker.