Shaded pole single phase induction motors

Shaded pole single phase induction motors

 · Shaded Pole Induction Motor is a type of single-phase motor consists of a stator and a cage-type rotor. It is a self-starting motor. It is also called as Shaded Pole blogger.comted Reading Time: 3 mins What is Shaded Pole Induction Motor: Shaded pole induction motor is nothing but a self-starting single phase motor whose main pole is shaded by the auxiliary winding or an external winding. This external winding is called a shaded coil or shaded band. The external winding does not have electrical contact with the input power supply  · Shaded Pole Single Phase Induction Motors. The stator of the shaded pole single-phase induction motor has salient or projected poles. These poles are shaded by a copper band or ring, which is inductive in nature. The poles are divided into two unequal halves

Shaded Pole Induction Motors - Working and Construction

Shaded pole motor is one of the types of single phase induction motorswhich are used for producing a rotating stator flux in order to make the single phase induction motor a self starting one.

Let us discuss the constructional details, diagrams and working of shaded pole motors in detail. Like any other motors the shaded pole induction motor also consists of a stator and rotor.

The stator is of salient pole type and the rotor is of squirrel cage type, shaded pole single phase induction motors. The poles of shaded pole induction motor consist of slots, which are cut across the laminations.

The smaller part of the slotted pole is short-circuited with the help of a coil. The coils are made up of copper and it is highly inductive in nature. This coil is known as shading coil. The part of the pole which has the coil is called the shaded part and the other part of the pole is called unshaded part. Now let us consider that an alternating current is passed through the excited winding which surrounds the pole.

Due to the presence of shaded pole single phase induction motors coil, the axis of the pole shift from unshaded part to shaded part. This shifting effect is equivalent to the physical movement of the poles, which is nothing but the rotation of poles.

So the rotor starts rotating in the direction of the shift from unshaded part to shaded part. Now let us discuss why the axis shaded pole single phase induction motors occurs when current is passed through the winding and how the shading coil aids in producing the shift.

The current carried by stator winding produces alternating flux. The distribution of flux through the poles is greatly influenced by the shading coils. When the alternating current through the coil increases, it induces a current in the shading coil. The direction of current in shading coil is such as to oppose the cause producing it from Lenz law.

The cause is the alternating current. So the flux in the shading coil decreases and it opposes the main flux.

Hence the flux mostly crowds or shifts towards the unshaded part of the pole, shaded pole single phase induction motors. So the magnetic axis lies along the middle of the unshaded part. It is denoted as NC in the picture below. Now consider that the alternating current has reached its peak or somewhere near the peak. Here the rate of change of current is low, as it has already reached the peak or it is very close to peak value. Since the change is current is so small, the induced current at shading ring is also small and negligible.

So the shading ring does not affect the distribution of main flux. Shaded pole single phase induction motors flux is distributed uniformly and the magnetic axis lies at the center of pole face. The magnetic axis is denoted as ND in the picture.

The alternating current, after reaching the peak starts to decrease rapidly and in turn decreases the main flux. The change in current induces a current in shading coil. According to Lenz law the direction of this current is so as to oppose the cause producing it the decreasing alternating current.

So the flux in shading coil opposes the decrease in main flux and strengthens it. This increases the strength of main flux in the shaded part. SO the magnetic axis shifts itself to the middle part of shaded pole. The magnetic axis denoted as NE in the picture below. So it is quite clear that during the positive half cycle of the alternating current, North Pole shifts from unshaded part to shaded part and during the negative half cycle, the South Pole shifts along shaded pole single phase induction motors unshaded part to shaded part.

This effect is nothing but the rotation of poles from left to right. Thus shaded coils aids in producing the rotating flux and thus the single phase Induction motor is converted into self starting one using the Shading coil. Due to fixed of position of shading coils, the direction of rotation of such motors cannot be changed. Due to their low starting torques they are mostly employed in small instruments, toys, small fans, electric clocks, hair dryers, ventilators, circulators etc.

Thus we have discussed in detail the working, constructional features and applications of Shaded pole Single Phase motors. Page content. Introduction Shaded-Pole SIngle-Phase Motors Why Magnetic Axis Shift Takes Place? Advantages, Disadvantages and Applications, shaded pole single phase induction motors. Introduction Shaded pole motor is one of the types of single phase induction motorswhich are used for producing a rotating stator flux in order to make the single phase induction motor a self starting one.

Shaded Pole Induction Motor | Working & Applications | Electricalvoice

Shaded pole motor is a split-phase type single phase induction motor. The shaded pole motor is very popular for ratings below HP (~ 40 W) because of its extremely simple construction. It has salient poles on the stator excited by a single-phase supply and a squirrel cage blogger.comted Reading Time: 4 mins  · Shaded pole motor is one of the types of single phase induction motors, which are used for producing a rotating stator flux in order to make the single phase induction motor a self starting one. Let us discuss the constructional details, diagrams and working of shaded pole motors in detail  · The stator of the shaded pole single phase induction motor has projected poles or salient. These poles are shaded by copper band or ring which is inductive in nature. These poles are devided into two unequal halves. The smaller portion carries band and is called as shaded portion of the pole