On Sun, 31 May 2009 14:15:02 -0500, -MIKE-
wrote:

Yeah, then I guess I just don't understand HP and how it's rated on
different machines and motors and whatnot.

1 HP = 746 watts.

When you're talking about AC motors, the "real" horsepower output of
the motor, regardless of the marketing hype, will be fairly close to:

HP = (.75 * Amps * Voltage)/746

Where Amps and Voltage are the dataplate values on the motor or
appliance. The .75 fudge factor is a ball park estimate to account for
electrical and mechanical efficiencies which are always less than 100%
and for the AC power factor which will vary with the load on the
motor. High load, higher power factor. Low load, lower power factor.

Overall motor efficiencies vary from type to type, and from model to
model within the same type, but when comparing two similar motors,
it's usually a good assumption that the higher amperage motor will be
the more powerful of the two.

Tom Veatch
Wichita, KS
USA