On 01/27/2013 08:28 PM, Donald H Locker wrote:
> John Popelish's response is most comprehensive. Power
> consumption is affected by a number of factors, including
> power required by the fluid moved but also by the chain
> of efficiencies leading to that moving fluid. All effects
> must be considered.
I forgot to include the efficiency of the speed circuit
feeding the motor. The answer is very different for a big
resistor in series with the motor or a variable frequency
drive. Switching motor windings to change the number of
effective poles), for an AC induction motor, eliminates this
consideration. Changing pulley sizes does, also.