A little OT but can someone explain why small electric motors are rated only
in amps while slightly larger ones are rated in HP? My Dad is looking at
buying a new bench grinder and is having trouble figuring out how to compare
various models from Delta, Ryobi etc. He isn't going to be happy with the
performance of the smaller ones but won't be happy paying for the larger
ones. He's looking for an 8" grinder. Any thoughts on brands/models?

Everything's rated in amps, it's just in larger motors where companies go to
the trouble of publishing HP figures in addition. Of course, you also have to
remember that lots of small or cheap tools are sold with inflated "peak HP"
ratings. Basically meaningless in the real world.

746 watts (or a little over 6 amps) equals one US horsepower. However, you
won't get that on this planet due to efficiency, power ratings, etc. I think
it's along the lines of 10A to every HP in modern induction motors. More power
out of universal (brush) types. Just use it as a basic guide to know that a 12
amp shop vac doesn't make 6.5HP, no matter what Sears says.

Baldor, Milwaukee, Dayton, Wisotta (sp?) are some of the best grinder makers.
Pricy, though. Among the imports, Delta, Jet, and DeWalt are good. Ryobi and
Sears (frquently the same tool) grinders get worse every time a new model comes
out.

GTO(John)

A little OT but can someone explain why small electric motors are rated only
in amps while slightly larger ones are rated in HP? My Dad is looking at
buying a new bench grinder and is having trouble figuring out how to compare
various models from Delta, Ryobi etc. He isn't going to be happy with the
performance of the smaller ones but won't be happy paying for the larger
ones. He's looking for an 8" grinder. Any thoughts on brands/models?

1 HP = 746 watts

If you want to have some fun with math, see:
http://www.engineersedge.com/electrical_equations.htm

I think I would check around and see what has been doing the job for others
rather than buy based on the numbers vs. $$.

Parts availability, customer service etc need to be included in the equation
also.

DexAZ

"Colin Butler" wrote in message
...
A little OT but can someone explain why small electric motors are rated
only
in amps while slightly larger ones are rated in HP? My Dad is looking at
buying a new bench grinder and is having trouble figuring out how to
compare
various models from Delta, Ryobi etc. He isn't going to be happy with the
performance of the smaller ones but won't be happy paying for the larger
ones. He's looking for an 8" grinder. Any thoughts on brands/models?

I could post the table from NEC article 430 but I amy already have the
copyright police closing in ;-)