Is a 1 AWG grounding conductor acceptable for a system over 4,000 volts?

A 1 AWG grounding conductor is not acceptable for systems over 4,000 volts due to the requirements set forth in the National Electrical Code (NEC). For higher voltage systems, the size of the grounding conductor must be adequately proportionate to ensure that it can safely handle the fault current and provide effective grounding. The NEC specifies minimum sizes for grounding conductors based on the voltage of the system, and typically, larger conductors are required for systems operating at higher voltages to ensure proper safety and protection against electrical faults.

In this case, for systems over 4,000 volts, the grounding conductor must be larger than 1 AWG, as smaller conductors would not provide the necessary capacity to handle potential fault conditions effectively. This ensures that both personnel and equipment are protected from electrical hazards. Therefore, the response indicating that a 1 AWG grounding conductor is not acceptable for such systems aligns with NEC guidelines and the fundamental principles of electrical safety.