On Sep 11, 1:06 pm, Chris Friesen wrote:
wrote:
My new edge sander was delivered today, Grizzly 6x80. In the version
of the manual on the website they list it as 1.5 HP 16A/8A. But in
the manual that came with it and on the nameplate on the motor it says
1.5 HP 20A/10A.

Now I should probably run a dedicated 220V line to it regardless, but
for the time being I thought I was going to be fine on my 20A 110V
circuit. I just think it's very weird because if it's really drawing
20A then why are they calling it 1.5 HP? 20A should give 2 HP.

Horsepower ratings aren't always all that precise, and motor efficiency
can lead to higher max draw.

But marketing departments making specs sound as good as they can is
right up there with death and taxes. The Sawstop contractor saw
actually says 1-3/4 HP which I've never seen anything say.

I suspect it's simply an inefficient motor.

I found this link which says the minimum efficiency for a NEMA "Design
B" should be 79%. I don't know what a Design B is.

http://www.engineeringtoolbox.com/el...ncy-d_655.html

Even at 75%, 20A at 115V is well over 2 HP. Or going the other way,
1.5 HP at 75% is 13A, which is exactly what my table saw says.

Also, it's likely that the
motor will hardly ever actually draw the rated amount. Most shop tools
(except for dust collectors) aren't running anywhere near full load.

The manual actually has a page where it says the machine will draw 10A
on 220V under normal use. Which doesn't make any sense, but that's
what it says.