What happens to a GFCI protection device when it fails?

A Ground Fault Circuit Interrupter (GFCI) is designed to protect against electric shock by interrupting the current flow when a ground fault is detected. When a GFCI fails, it does so by failing to perform its protective function. In this context, if the switching contacts were to remain closed, the device would continue to supply power but without the necessary ground fault protection.

This situation poses a significant safety hazard, as users may assume they are protected when in fact they are not. Such failures can often go unnoticed, leaving circuits unprotected against ground faults that could lead to electric shock or fire hazards.

In contrast, it is not typical for a failed GFCI to alert the user, cut off power, or reset itself, which aligns with the nature of its protective measures. Understanding these failure modes is crucial for recognizing the importance of regularly testing GFCI devices to ensure they are functioning correctly and to maintain safety in electrical systems.