According to the NEC, the minimum circuit operating voltage for a 240-volt circuit with a 3% voltage drop is approximately what value?

• A. 232 Volts
• B. 240 Volts
• C. 235 Volts
• D. 226 Volts

Answer: (A)

Think of voltage drop as the loss from the supply to the load. If you allow a 3% drop on a 240 V circuit, the voltage at the far end is 240 × 0.97 = 232.8 V. The minimum circuit operating voltage is therefore about 232–233 V. The closest option is 232 volts. The other values either ignore the drop, imply a smaller drop, or imply a larger drop than 3%.