On 6/26/2010 1:31 PM, Tony wrote:
I'm trying to figure the cost of running the central AC in my house.
Inside was fairly easy, a 1/2hp fan motor. Outside the numbers on the
plate from the factory are long gone. I found on the fan motor that it
is 1/8hp. Now the compressor.... On it is listed the voltage but not the
amps or watts but it does list the LRA (locked rotor amps) of 105.0 It
is a Copeland CR38K6-PFV-370.

I found this site but even this isn't very useful to me only giving me
the RLA of 19. I read the RLA is "rated load amps" and does not mean
"Running Load Amps". RLA being the most current it should draw under the
harshest conditions.

http://www.nordyne.com/literature/8569%20Compr.pdf
The best would be to compare the
electric meter with the unit running and
not running. This way you will have
actual watt-hours and you don't have to
think of things like power factor, etc.
But, it will change depending on
temperature. And the run time will vary
when the temperatures are cooler than
when it is just plain hot outside.