What device will de-energize a circuit if the current to ground exceeds a predetermined value?

A Ground Fault Circuit Interrupter (GFCI) is designed to protect individuals from electrical shock by monitoring the current flowing through a circuit. If it detects any imbalance between the incoming and outgoing current—specifically when the current to ground exceeds a predetermined value—it will quickly disconnect the power. This rapid response is crucial in preventing shocks that could occur in wet or damp locations where electrical equipment is frequently used, such as bathrooms, kitchens, or outdoor settings.

In contrast, a fuse and a circuit breaker are generally protection devices that stop the flow of electricity due to overloads or short circuits, but they do not specifically monitor for ground faults. A transformer, on the other hand, changes voltage levels in an electrical circuit but does not provide any protective function related to grounding. Understanding the purpose of a GFCI is essential for ensuring electrical safety, especially in environments where the risk of ground faults is heightened.