wrote in message
...
I have a 1/2HP electric motor on a power saw, and that motor is fairly
large. I just bought a portable pump for transferring water from
items such as a flooded washing machine, bathtub with clogged drain,
etc. That motor is only about 35% of the size of the motor on my
power saw, yet the tag says it's a 1/2HP motor.

How can one 1/2HP motor less than half the size of another 1/2HP motor
produce the same horsepower? Is there another factor to take into
account besides the HP? Is it torque, or some other factor? Somehow
I cant see how this small pump motor could power my saw....

From:

http://machinedesign.com/article/gre...nt-motors-0619

Six factors account for most of the energy lost in an ordinary induction
motor: iron-core losses, stator resistance, rotor resistance, windage and
friction, and stray load losses. NEMA Premium motors minimize these factors
in a variety of ways, usually through use of high-grade steel and increased
use of active materials. For example, high-grade steel in the rotor lets
manufacturers use thicker laminations that take less time to manufacture,
but which still reduce ironcore losses caused by circulating currents.
Similarly, manufacturers reduce stator resistance by boosting the amount of
copper in the stator windings.

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Bobby G.