ECN Forum Forums General Topics of the Trade General Discussion Area Pool pump 220 or 110

Have pool pump on 110v with a GFI breaker. Had heard it was cheaper to run as 220v. Is it worth it to rewire? 1 HP motor
Thanks

No,it is not worth it. You pay for electriity in watts (power). If you run it at high voltage (240 volts)the amps will drop about in half. But for quick figuring, Volts X Amps = Watts.
So lets say your motor draws 10amps at 120 volts. that is, 10 x 120 = 1200 watts. Now lets say you hook it up to 240 volts and it draws only 5 amps now. That is 5 x 240 = 1200 watts. same thing.
Hope this helps. Have a safe and shockfree time in your pool!

I was always taught to use the highest voltage rating on a motor nameplate when possible. Power savings (if any) is one reason, but, does the motor not run cooler (less stressed), last longer, and run more efficiently when hooked up 220 vs. 110?

When the motor is set up for 110 volts the windings are connected parellel. When the motor is connected for 220, the windings are connected in series. Therefore internally on the windings you have the same voltages and current flows on each set of windings.
That's the basic gist of it. I'm not a motor specialist by any means. Perhaps someone with more experiance would like to elaborate.

Joe is correct. This sketch might help illustrate what he said.



Ed

Your motor will not be cheaper to run, but it will run more effeciently at the higher voltage. The higher the voltage the lower the ampacity.

As some have already stated lower amps

the key to the higher voltage is you get lower amp draw on a circuit so you can run smaller wire and conduit which reduces cost of install

Is the start winding on the second drawing supposed to be in series with a run winding?

Yes, it is. It is a 115 volt winding so has to be in parallel with one half of the run windings (for the high voltage connection).

The two run winding sections in series act as a voltage divider to split the 230 volts into two equal voltages of 115 each.

It will draw it's current through one of the run windings for a few seconds during starting, but that doesn't cause a problem.

All three windings are rated at 115 volts.

Ed
PS - These comments and the diagram refer to the basic general purpose motor. There are many other winding arrangements.

[This message has been edited by electric-ed (edited 11-01-2002).]

The higher the voltage the less amperage equals smaller wire and OCP.

A little bit of savings I guess.