I am replacing the condenser fan on my Lennox unit. Got the new Emerson motor and new capacitor, but the old capacitor has 3 lugs on it- one to the motor, one to the compressor and one to the contactor. The new capacitor only has 2 lugs. Is this capacitor only for the motor? I'm pretty sure the old motor was bad since it would spin for a minute or two at roughly half speed before stopping. (I assume bad winding since this is a 220V motor) I just don't know if I should leave compressor hooked up to old capacitor, especially since it may have caused the motor failure?

Leave the compressor hooked up to the old capacitor (do not remove the wires going to the compressor or to the power supply).

Wire the new capacitor as per the motor manufactures wiring diagram on the side of the new motor.

The 3 lug capacitor is two capacitors in a smaller package with a common terminal. The common terminal goes to the contactor.

There is one cap for the compressor and one cap for the condenser fan.

The condenser fan has a specific capacitance value for the replacement.

Use the new cap with the new fan, but you may have to run an extra wire from the common(contactor) terminal.

Replacement condenser motors can have 3 or 4 wires as well.. Again, one wire is a common terminal.

Thanks fellas.

The wiring diagram on motor shows nothing about bringing power to the capacitor. Do you think it draws current through the motor then?

Also, how likely is it in your experience that the compressor capacitor has to be replaced? Not from a test standpoint, but from your experience as to life span. The unit is 6 years old. I will test it (which I will assume will show fine for now), but are we on a ticking clock so to speak?

Thanks again for your help. I will sleep much better now.

Then I'll bet you have a 4 wire motor. It's done internallly.

Age kills caps. So does the environment, particularly temperature. 5 years is not unusual. Always get a new cap with a new motor.