motor and generator

[MaxHeadRoom78]

The shading ring causes a phase shift in that part of the stator, WRT the main winding, effectively achieving a similar effect to a start capacitor in a larger motor.
Essentially what was stated.
Max.

 

[dr pepper]

Yes I understood that, it was the effect of the shade on current I was wondering about.

 

[MaxHeadRoom78]

The effect of the shading ring produces a current which ideally is 90° shifted from the main winding, as it is essentially a shorted turn, it also gets quite hot.
The shading ring current is not in phase with main winding current so it is not additive.
Just not considered an efficient motor due to the waste heat, low starting torque, and power factor very low, hence the low power applications
Max.

 

[PG1995]

Thank you.

That is the reason a 4 pole induction motor operating from 60 Hz will not run at 1800 RPM, but at a lower speed, like 1725 or 1750 RPM.

Are you talking about single phase or three phase induction motors? I have read that when it's said something like 2-pole three phase induction motor, it really means that there are two poles per phase; total 6 poles. Thanks.

 

[MaxHeadRoom78]

The same applies to 3ph or 1ph motors.
With a 2 pole motor there is one electrical revolution per mechanical rev.
Max.

 

[dr pepper]

Yes there is a magnetic phase shift, however there are 2 magnetic fields produced to turn the rotor as only one field has very low starting torque, so current draw is going to be affected too, so are you saying there will be 2 current peaks?

Edit: I looked into it, the shade delays the magnetic field using eddy currents, and electrically acts as a large inducatce, so there will be 2 current peaks per the motors electrical rotation.

 

[MaxHeadRoom78]

Late replying, I was locked out of the site for some reason?
As I posted in #23, there is a phase difference (peaks) of 90° between the two waveforms.
Max.