Motor Power Supplies

<...WHAT WILL BE MOTOR PERFORMANCE...>

1. Someone will object to the use of Caps Lock
2. The motor will turn slower
3. Therefore the cooling fan will not be so effective
4. If delivering the same torque then it will run hotter, though only the load characteristics can determine this
5. It will be less efficient
6. It may have a shorter working life
7. It will be a poorer choice than selecting the correct motor for the job at hand.

GA, you get a vote form me.

1. Someone will object to the use of Caps Lock... OK, I'll do it. DON'T USE ALL CAPS! It makes it harder to read.
   
2. The motor will turn slower... Specifically, 20% slower. However you are also reducing the voltage by 6% and the torque is reduced by the square of the applied voltage, so .94² means you will have 88% of rated torque. But because HP is a function of torque AND speed, the lower speed buys back SOME of the HP. So 20% lower speed, but 12% lower torque still equals lower HP capacity. Your 300HP motor has become a 272HP motor.
   
3. Therefore the cooling fan will not be so effective... Check, so lower power capacity, less effective cooling = more heat in the motor = shorter life. For every 10 degree increase in motor operating temperature over rated, the motor winding insulation life is cut in half.
   
4. If delivering the same torque then it will run hotter, though only the load characteristics can determine this... Not to be too picky, but what he means is that if the LOAD requires the same amount of torque, the motor will be incapable of delivering it, so the slip will increase, the motor will draw more current to attempt to do the same work (see above) and the extra current will raise the temperature and cause the motor to die sooner than later.
   
5. It will be less efficient... Yes, especially if you describe efficiency in relation to being able to perform the job at hand! The motor may not work at all!
   
6. It may have a shorter working life... I think that is a given. It WILL have a shorter life.
   
7. It will be a poorer choice than selecting the correct motor for the job at hand.... Bingo.