Why Is The Difference Between 208V Power and 230V Power Important?

Motors are rated for 10% over or under the nameplate voltage listed on the motor. This is a NEMA requirement. So, a 230 volt motor can operate as low as 207 volts. When a motor is rated at 208/230 volts this means the motor will operate at the 208 volt rating, not 10% under the 208 volt rating. The motors that are truly intended for 208 volts are nameplated for 200 volts. This motor would allow the minimum voltage to be 180 volts.

Running motors at a lower voltage will decrease the life expectancy by 50%. The motor will also have reduced acceleration torque and higher current draw.

Below is a representation of the difference between 208/230 volt wiring. Note that the 230 volt will have a wild leg (230 volts to neutral) on that particular leg.