On Wed, 09 Feb 2011 15:10:56 -0600, Ignoramus25972
wrote:

On 2011-02-09, Jon Danniken wrote:
If an electric motor with 80% efficiency is pulling 16A at 120V, what is the
horsepower?

Going by (16)(120)(0.8)/746, I get about 2 HP.

Is this right?


Sounds right to me.

i
Pretty close for 16 amp running current - but how much does it draw
on startup??? Most motors that will draw 16 amps on startup will draw
closer to 7 under normal running conditions - which is 1 HP.
Not 2 many real 2HP motors will start on a standard 15 amp breaker or
fuse, and many will not start on a standard 20 amp breaker or fuse. A
20 amp slow-blow fuse will GENERALLY start a 2HP motor under a
reasonable(light) load like an unloaded compressor or a 10" table saw.