How a shaded pole motor operates?
A Shaded Pole motor is an AC single phase induction motor. The auxiliary winding, which is composed of a copper ring, is called a shading coil. When power is applied to the stator, the flux in the main part of the pole induces a voltage in the shading coil, which acts as a transformer secondary winding.
How the shaded pole motor is started?
Definition: A shaded pole induction motor is a simple single-phase induction motor, which is self-starting with one of the poles shaded by the copper ring. The other name of the copper ring is a shaded ring, where it acts as a secondary winding motor. This motor is made up of stator and a rotor which is cage type.
What are the parts of the shaded pole motor?
Shaded Pole Induction Motor
- Definition: The shaded pole induction motor is simply a self-starting single-phase induction motor whose one of the poles is shaded by the copper ring.
- Stator – The stator of the shaded pole motor has a salient pole.
- Rotor – The shaded pole motor uses the squirrel cage rotor.
What is the capacity of a shaded pole motor?
They are built in power sizes up to about 1⁄4 horsepower (190 W) output. Above 1⁄3 horsepower (250 W), they are not common, and for larger motors, other designs offer better characteristics. A main disadvantage is their low efficiency of around 26 %.
What is the purpose of shading coil in shaded pole motor?
function in shaded-pole motor The shading coil delays the establishment of magnetic flux in the region that it encircles and thus produces a small component of rotating field at standstill.
What is the starting torque of a shaded pole motor?
about 50%
The shaded pole induction motor produces a very small starting torque about 50% of full load torque. The efficiency of the shaded pole motor is low because of continuous power loss in the shading coil. It is suitable for small devices which require low starting torque.
Why shaded-pole motor is suitable for low power application?
Shaded-pole motors are best suited to the low-power household application, because the motors have low starting torque and efficiency ratings. Because of the weak starting torque, shaded-pole motors are built only in small sizes ranging from 1/20 to 1/6 hp.
How does a shading coil work?
A short-circuited coil for partially delaying change in magnetic flux by using the current generated by mutual inductance between the magnetic pole of a DC electromagnet that has been partially encased and an excitation coil. Shading coils reduce the vibration of the moving parts.
What is the speed of a shaded pole motor?
A shaded pole motor is a type of induction motor, just using some neat magnetic tricks to generate a second phase. It runs at slightly below synchronous speed, the slip depends on the torque. For a simple 2 pole motor, you’d expect it to run at perhaps 90% of 3000 rpm (50 Hz countries), or 3600 rpm (60 Hz).
What is the disadvantage of shaded pole motor?
Disadvantages of Shaded Pole Motor : Low power factor. High losses. Less efficiency. Difficult in speed reversal as it requires expensive copper rings.
How does a shaded pole relay work?
Shaded Pole Type Induction Relay : A shading ring or coil is made of copper (Cu) and encircles the part of the pole face of each pole at air-gap. Thus, two alternating fluxes are produced and are displaced in time and space. This resultant torque rotates the disc, which in turn operates the relay contact mounted on it.