According to NEC, the voltage on non-power-limited circuits may not exceed?

According to NEC, the voltage on non-power-limited circuits may not exceed?

• A. 120 V
• B. 240 V
• C. 600 V
• D. 480 V

Answer: (C)

The voltage on non-power-limited circuits is kept to a maximum of 600 volts. This threshold defines a safety boundary in the NEC: circuits that aren’t restricted as “power-limited” must still stay within a voltage range that equipment, insulation, and protective practices are designed to handle. Exceeding 600 volts would move the installation into a higher-risk category that requires stricter rules and ratings for wiring, equipment, and safety procedures. So while common voltages like 120, 240, or 480 volts appear in practice, the NEC sets 600 volts as the upper limit for non-power-limited circuits.

The voltage on non-power-limited circuits is kept to a maximum of 600 volts. This threshold defines a safety boundary in the NEC: circuits that aren’t restricted as “power-limited” must still stay within a voltage range that equipment, insulation, and protective practices are designed to handle. Exceeding 600 volts would move the installation into a higher-risk category that requires stricter rules and ratings for wiring, equipment, and safety procedures. So while common voltages like 120, 240, or 480 volts appear in practice, the NEC sets 600 volts as the upper limit for non-power-limited circuits.