I had a previous thread, but ignore it as I have the details correct
this time.

To start the motor did spin when powered.

I helped my neighbor disassemble a pump motor, we needed to hold the
rotor in order to remove the broken impeller, so we pulled the stator
off to get access to the rotor. We had to remove the centrifugal lever
assembly from the shaft in order to remove the stator. We remover the
broken impeller and reassembled the motor. Reinstalled the centrifugal
lever assembly and the switch the it operates.

Now at power up the motor just hums.
The rotor spins freely.

We didn't unhook any wires, just pulled the stator off to get access to
the rotor. I marked the end plate and stator and put it back together
the same way.

Any ideas, why the motor hums.


I want to understand the operation of the motor.

First I'm aware of motors with a start winding, it is energized until
the motor spins fast enough to move the centrifugal lever assembly which
open the switch to de-energize the start winding.

On this motor the centrifugal lever assembly CLOSES a switch when it
gets up to speed. Opposite of what I thought would happen. The motor has
a start capacitor and another part I'm I not aware what it is.
Here is a picture of the same type motor. In the picture the wrench
is causing the centrifugal lever to swing and open the switch, it can't
be seen well in the picture.
Also the black part with three wires, white, yellow, and blue, what is
it's function.
http://s395.photobucket.com/user/Qma...426fb.jpg.html

Thanks for your help,
Mikek