Ground-fault protection of equipment is generally required for which of the following?

Ground-fault protection of equipment is an important safety measure designed to minimize the risks associated with electrical faults that can lead to fatal shocks or fire hazards. The correct answer focuses on grounded electrical services that are solidly grounded and fall within a specified voltage range.

In general, equipment that operates at more than 150 volts to ground but does not exceed 1,000 volts phase-to-phase is required to have ground-fault protection. This is because faults in this voltage category can pose significant risks, and the protection mechanisms are designed to detect ground faults and interrupt the electrical supply quickly to mitigate those hazards. Solid grounding specifically helps in ensuring that any fault current has a clear low-resistance path, which is critical for effective operation of protective devices.

Understanding the voltage thresholds and grounding methods is key in electrical safety practices, which is why the characteristics of solidly grounded services in this voltage range are crucial. This regulation ensures that the system can operate safely under fault conditions, ultimately protecting both equipment and personnel.