How is ground-fault protection defined in Article 690?

Ground-fault protection is defined in Article 690 as a feature that detects and interrupts ground faults. This is crucial for enhancing the safety of solar photovoltaic (PV) systems. Ground faults occur when there is unintended contact between an energized conductor and ground, potentially leading to electric shock hazards or fire risks. Ground-fault protection systems monitor the electrical circuit for such faults and, upon detection, they act quickly to isolate the affected circuit by interrupting the electrical supply, thereby mitigating risks associated with electric shocks and equipment damage.

This feature is especially important in outdoor and exposed installations, where moisture and environmental conditions can increase the likelihood of ground faults. Proper implementation of ground-fault protection is mandated by the NEC to ensure that both personnel and property are safeguarded against these types of electrical faults.

In contrast, the other options focus on unrelated concepts. Preventing signal interference does not pertain specifically to ground faults, protection against lightning strikes involves different protective measures, and methods for improving efficiency are not directly related to detecting and interrupting ground faults in electrical systems. Hence, the focus of ground-fault protection in the context of NEC Article 690 is primarily about detecting electrical anomalies to protect circuits and personnel from hazards.