On Nov 30, 12:59*am, Sjouke Burry s@b wrote:
wrote :

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....

Thanks

1. Skimpy design.
2. The waterpump may be cooled a bit by the pumped water.
3. The designer might have counted on short runs with
* *enough cooling down in between.
All that allowes a smaller motor.

I think that the water cooling may be a big part of it. Heat buildup
is part of the reason regular continuous-duty electrical motors are so
large - for example, an automotive starter motor develops more power
than likely anything in your workshop but is relatively small -
because it's not designed for continuous usage, so heat buildup is
pretty much neglected as a design consideration. But try to use one
under load for more than a couple minutes at a time, and see what
happens...

nate