What is a Shaded Pole Induction Motor?
A shaded pole motor is a type of self-starting, single-phase induction motor where a portion of a pole is shaded by a copper ring, creating a rotating magnetic field.
This “shaded ring” acts as a secondary winding, and the shading causes a delay in the magnetic flux in that part of the pole, enabling the motor to start.
Here’s a more detailed explanation:
Single-Phase Induction Motor
It operates on a single-phase AC power supply, unlike three-phase motors which typically require three phases.
Self-Starting
Unlike some single-phase motors that require an external starting mechanism, shaded pole motors can start on their own due to the shading effect.
Shading Ring
A copper ring or band is placed around a portion of the stator pole, creating a “shaded” area.
Rotating Magnetic Field
The shading effect causes a phase shift in the magnetic flux, creating a rotating magnetic field that drives the rotor.
Direction of Rotation
Shaded pole motors typically rotate in one direction, and reversing the direction is not possible.
Low power and Efficiency
These motors have relatively low starting torque and efficiency, making them suitable for low-power applications.