On Wed, 22 Dec 2004 04:13:56 GMT, "BillyBob"
vaguely proposed a theory
.......and in reply I say!:

remove ns from my header address to reply via email


"Duane Bozarth" wrote in message
...

What a testament to the failure of science education in the general
populace (Bob, not you Nova)...

Are you saying my statement was wrong?

I feel that the quote below is because of two factors (rusty memories
struggle up through the ooze):

- The motor is not running at synchronous spped eve with no load, so a
larger HP motor wil draw fractioannly more.

- The motor will run at near-synchronous until it stall, then it will
start to draw the (much) heavier "starting" current, although it's
failing to do the job. Because it;s running at near-synchronous while
it's working properly, the correctly-matched motor will use less power
even when fully loaded. Less wastage.

However, if I had the choice as a hobbyist between a free 2HP motor
and a $100 1 hp one, I woud use the free one for sure! G

http://www.eng-tips.com/gviewthread..../237/qid/18465

"4.2.2. Efficiency at Low Load
When a motor has a greater rating than the unit it is driving
requires, the motor operates at only partial load. In this state, the
efficiency of the motor is reduced (see Figure 4.2 ). The use of
oversized motors is fairly common because of the following
conditions:"


"Replacement of underloaded motors with smaller motors will allow a
fully loaded smaller motor to operate at a higher efficiency. This
arrangement is generally most economical for larger motors, and
only when they are operating at less than one-third to one-half
capacity, depending on their size"