Re: (ET) Fw: E20 motor at 48V

["Konstanty, Walter (GE Indust, ConsInd)" <Walter Konstanty ge com>]

T = (HPx5252)/RPM

  Gas engines are rated in PEAK HP and develop rated torque at high
speed.  Ex: 4.3 ftlb @ 3,600RPM
  Electric motors are rated in CONTINUOUS HP and typically develop that
at 0 RPM which drops off above base speed.

 Marketeers over-rate things like that 3.5HP vacuum that only draws 5
amps......it's the high starting current converted to HP and not what it
can really put out.....check the motor rated amps and that will tell you
the real story on those vacuums and compressors.

  It's torque you want......a rule of thumb is about 3:1 on electric vs
gas.  The Elec-Trak numbers were based on gas tractor sizes and not
comparative gas to electric motor HP's.

...Walt
-----Original Message-----
From: elec-trak-bounces cosmos phy tufts edu
[mailto:elec-trak-bounces cosmos phy tufts edu] On Behalf Of Jerry
Rhodes
Sent: Thursday, January 03, 2008 11:20 AM
To: Elec-trak Mail List
Subject: (ET) Fw: E20 motor at 48V
>I sure hope everyone is taking notes, this is the best lesson i've seen

>on dc motors sense school, and has that been a long time ago, THANKS 
>Walt, question, is there a way to equate electric hp to ICE hp  i.e...a

>3hp electric to = to a xx hp ICE ??? my old brain recalls an old 
>prof'er at UWi saying 5.5 to 1  i.e... 3hp DC = 16.5/17 hp ICE or 
>about... I know it's not that easy....
>
> Jerry
>