In article , " wrote:
On May 5, 12:30=A0pm, Chris Friesen wrote:
On 05/05/2010 10:59 AM, wrote:

On May 5, 11:48 am, Chris Friesen wrote:
A good rule of thumb for most "normal" induction motors is 10A per HP =
at
120V.

Higher quality motors can do better, of course, but a "premium
efficiency" 1HP Baldor motor that costs $500 is still rated at 8.6A.

My bet is that a "normal" motor isn't much less. =A0There is more in
that motor than a few (more) pounds of copper (like a name plate).

I was curious, so I went and checked on Baldor's site.

I checked a few 3450rpm 1HP "general purpose" induction motors and the
FLA at 120V ranged from 11.8 to 15A. =A0Worse than I thought. =A0

Gack! You're right. I looked up a few sites and found 12-15A for a
general purpose 1-HP 120V motor (I thought motors were far better than
50% efficient). Nothing less than 12AWG!

Why? 14AWG wire will safely carry 20A. The NEC limits the *overcurrent
protection* on a 14AWG circuit to 15A, but also specifically lists the
ampacity of 14AWG copper as 20A with 60degC and 75degC insulation, and 25A
with 90degC insulation. [2008 NEC, Table 310.16]