John, series on 240, parallel on 120.
When you have sag and current goes up, it's up in the feed as well as in the
motor, so you actually do consume more power from the box, and a little more
in the motor (the IR heating).

Wilson
"John Sellers" wrote in message
. ..

wrote in message
...
The power is the same I (current) x E (voltage)
110V x 20 amps = 2200 watts
220V x 10 amps = 2200 watts. Period!
There are other loss that come into play (power factor) but lets
leave that stuff
alone!
Also, You are "using" the same current in the motor (at 110 Vs 220)
but since the
voltage drop doing to the motor increases (less voltage at the
motor), it draws
more current to make up for the power loss (2200 watts)! So it works
harder and
the power lines get hotter (that where the loss is going.)

Frank


This is almost correct, but your wording has me confused about what
exactly you meant to say.

At 120V, when the current is approximately 2x, the voltage drop is
greater in the feeder cable, so there's less voltage across the motor.
That equates to less current per winding (they're in series here).

At 240V, since the current is roughly half, there's less voltage drop
in the feeder, so more voltage is allowed across the motor, which will
slightly increase the current per winding (which are now paralleled).

Of course, these variables all change with each incremental bit of
developed power. So it's kinda moot.

And (to mention what others have alluded), it gets more detailed when
you start considering the counter-EMF, mutual inductance, load rate of
change, and power factor.

If you have the means to use 240V, just do it. It's advantageous.

Hope this helps.
John Sellers