A motor used in an electric furnace is rated at 230 VAC. What is the acceptable range of voltages?

In the context of electric motors, including those used in electric furnaces, the acceptable voltage range is typically defined by industry standards that take into account potential variations in supply voltage. When a motor is rated at 230 VAC, the National Electrical Manufacturers Association (NEMA) standards indicate that a typical acceptable voltage tolerance is ±10% of the rated voltage.

Calculating this range:

• The lower limit is 230 volts - 10% of 230 volts, which equals 207 volts.

• The upper limit is 230 volts + 10% of 230 volts, which equals 253 volts.

This provides a range of 207 to 253 volts, which falls within the acceptable operating conditions for the motor. Operating a motor within this specified voltage range ensures efficient performance and reduces the risk of damage due to voltage fluctuations.

In contrast, the other options either fall outside of this acceptable range or do not conform as closely to the ±10% standard expected for a 230 VAC rating. Thus, identifying 207 to 253 volts as the acceptable voltage range confirms its adherence to established electrical standards for motor operations.