For a 208 volt motor, what is the lowest allowable input voltage?

In determining the lowest allowable input voltage for a 208-volt motor, it is essential to refer to the specifications set by the National Electrical Manufacturers Association (NEMA) standards. These standards specify that a motor can safely operate within a certain range of input voltage.

For a 208-volt motor, the acceptable voltage range is typically around ±10% of the rated voltage. This means that the lowest allowable input voltage should be calculated as 90% of the rated voltage.

Calculating 90% of 208 volts gives us:

208 volts × 0.90 = 187.2 volts.

This calculation demonstrates that 187.2 volts is the minimum voltage that the motor should receive to function within safe operating conditions. If the voltage falls below this level, the motor may not start or operate efficiently, potentially leading to overheating or damage.

The other values provided do not align with this important guideline. While they may represent other operating conditions or voltages for different types of motors, they do not meet the established minimum requirement for a 208-volt motor as outlined by industry standards.