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In shaded pole motor, the direction of rotation of motor is
From shaded pole to unshaded pole
From the unshaded to shaded pole
Either 1 or 2
How supply terminal connected with the stator winding
From the unshaded to shaded pole
Quick Summary: In a shaded pole induction motor, the direction of rotation is always from the unshaded pole portion to the shaded pole portion. This is due to the phase lag created by the short-circuited shading coil, which causes the magnetic flux in the shaded portion to lag behind the flux in the unshaded portion.
In a shaded pole induction motor, the direction of rotation is always from the unshaded pole portion to the shaded pole portion. This is due to the phase lag created by the short-circuited shading coil, which causes the magnetic flux in the shaded portion to lag behind the flux in the unshaded portion.
╬жshadedтАЛ=╬жmaxтАЛsin(╧ЙtтИТ╬╕) тАФ represents the lagging magnetic flux in the shaded section
The shading coil acts like the secondary of a transformer, inducing a current that opposes the change in main flux according to Lenz's law. This creates a time-phase displacement between the magnetic fields in the unshaded and shaded sections of the pole. The net result is a progressive shifting of the magnetic field across the pole face, creating a weak starting torque that pulls the rotor from the unshaded part toward the shaded part.
The rotation direction is determined by the physical placement of the shading ring.
It is a non-reversible motor; changing supply polarity does not change direction.
The starting torque is very low due to the small phase angle difference between fluxes.
Extremely simple construction
Low cost and maintenance-free
Self-starting capability without auxiliary components
Very low starting torque
Low efficiency and power factor
Limited to small power ratings (typically below 50W)
Table fans and small exhaust fans
Hair dryers and electric clocks
Small toys and record players
The shading coil is a heavy copper ring placed around a small portion of the pole piece.
Option A is incorrect because the rotor is pushed away from the leading flux (unshaded) toward the lagging flux (shaded).
B is correct тАФ The rotation is always directed from the unshaded pole toward the shaded pole due to the phase lag induced by the shading coil.
Always remember that in shaded pole motors, physical modification of the shading ring position is required to reverse the direction, as standard supply lead swapping has no effect.