running 480v rated motor on 440 volts

Status
Not open for further replies.
L

larryskipper

Member
I have a 480 volt, 3 phase rated motor and only 440 volt service. Was wondering if I can run the motor on the 440 volt 3 phase service or do I need to install a stepup transformer.
thanks guys...
 
Your motor nameplate will be 460 as its intended to run on 480V system, and allows for voltage drop.
Motors have a tolerance of +/- 10%. 10% of 480 is 48 volts or 432 volts. Overvoltage on a motor saturates the magnetic field and increases the current. If you have 485-490, which is not uncommon, your motor won't be happy.
Plus its a code violation. See 110.4
If the motor is used a lot, consider a replacement that will be far more energy efficient.
 
Status
Not open for further replies.
Top