What principle does ground fault protection use to ensure safety?

Ground fault protection uses the principle of current imbalance detection to ensure safety. This system monitors the flow of electrical current in a circuit, both the incoming and outcoming currents. Under normal conditions, the current entering a device and the current leaving should be equal. However, if there is a ground fault—meaning some of the current is leaking to the ground, which can happen through damaged insulation or other malfunctions—there will be an imbalance in the detected currents.

The ground fault protection system quickly identifies this imbalance and can promptly disconnect the circuit to prevent shock hazards, electrical fires, and equipment damage. This proactive detection is critical in environments where safety is a primary concern, especially for workers around electrically powered equipment.

Other options, such as voltage isolation, amplifier output, and resistance measurement, do not address the critical requirement for immediate detection of current flow discrepancies that indicate a ground fault. While they might play a role in different safety measures or equipment functions, they do not directly serve the essential purpose of ground fault protection.