Wow, an off-the-wall question that I have experience with!!!  We have a
stationary crane where I work.  It has an automotive a/c unit run by an
electric motor.  It is geared 2:1 (2 turns of the motor to 1 turn of the
compressor)  We use a 1725 rpm motor. I currently has a 5 hp 3 phase motor on
it and come summer, it will, no doubt burn up yet another motor.  This year
I'll up the hp in hopes of precluding another melt down to a 10 hp motor.  A
10 hp THREE PHASE 480v motor draws about 20 amps. (Guessing... the NEC* is at
work.)  AFAIK they don't even make a 120v 10 hp motor.  If they did, it would
draw about 80 amps.  That's a lotta juice, my friend.  Not really practical.

Wait, I just found the 1999 NEC*...  10hp single phase, 120v motor draws 100
amps.  That's 4 ga. wire to feed it.  About the size of your jumper cables.
Definitely more than your local campground will have available.

Jim

* National Electrical Code

> Folks,
>  We are planning a 3 week x-country camping trip this summer. Although we will
> not be camping with access to power most of the time, it would be nice to have
> the option of A/C at night if it is really hot out.
>
>   Not wanting to lug around a household A/C unit or install an oversize R/V
> unit, I thought, why not use the existing refrigerant loop?
>
>   - Add second clutch to Compressor with belt to A/C motor
>     (or some other means to power the compressor off
>      another source)
>   - Add control electronics
>     - Interior Air temp sense
>     - Evaporator fan control (interior fan)
>     - Temp sense of Condensor and Fan speed control to
>       reduce noise emissions
>     - Control of A/C motor
>     - Safety sense (Low press. sensor,etc..)
>     - battery charger to maintain charge with all the
>       12V fans running
>     - etc..
>
> Questions:
>     - How much power does the A/C compressor use?
>     - What is the most efficient speed (RPM) for
>       compressor operation?
>
> Just an idea.... Opinions?
> Thanks,
>  Ezra
> '88 Westy
> '86 944