In the NEC, a system over 1,000 volts that is solidly grounded at one point is referred to as what?

A system over 1,000 volts that is solidly grounded at one point is referred to as a single-point grounded neutral system. This terminology indicates that there is a specific point within the system where the neutral is connected directly to the ground, ensuring a defined reference point for voltage levels. This grounding technique helps to stabilize the voltage during normal operation and provides a path for fault currents, enhancing safety.

Solidly grounded systems have the advantage of reducing transient overvoltages, thus providing better protection for equipment. Additionally, they allow for effective operation of protective devices, which can significantly improve safety and reliability in electrical installations. This is essential in high-voltage systems where fault currents can be substantial, and proper grounding is vital for both personnel safety and equipment protection.

Other options do not accurately define the concept as described within the context of the National Electrical Code (NEC) for systems exceeding 1,000 volts.