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What is the range of the starting torque of shaded pole induction motor?
4
5
5
0.2-0.3
0.2-0.3
A shaded pole induction motor is a self-starting single-phase motor that utilizes a short-circuited copper ring (shading coil) to produce a rotating magnetic field ┬╖ Due to the high losses and low starting torque produced by the shading ring, its starting torque is extremely low, typically ranging from 0.2 to 0.3 times the full-load torque.
A shaded pole induction motor is a self-starting single-phase motor that utilizes a short-circuited copper ring (shading coil) to produce a rotating magnetic field ┬╖ Due to the high losses and low starting torque produced by the shading ring, its starting torque is extremely low, typically ranging from 0.2 to 0.3 times the full-load torque.
TsтАЛтЙИ(0.2┬аto┬а0.3)├ЧTflтАЛ тАФ The relation between starting torque and full-load torque
The stator has salient poles with a portion of each pole covered by a copper ring ┬╖ When an alternating current flows through the main winding, the shading coil induces a current that lags behind the main flux, causing the flux in the shaded portion of the pole to lag the flux in the unshaded portion ┬╖ This phase displacement creates a weak rotating magnetic field sufficient to generate a small starting torque.
It is a single-phase motor that does not require a centrifugal switch or capacitor.
The rotation is fixed from the unshaded to the shaded part of the pole.
Efficiency is very low due to copper losses in the shading ring.
Simple and robust construction
Extremely low cost
Maintenance-free operation
Very low starting torque
Low power factor
Low efficiency (5-35%)
Small fans
Toys
Hair dryers
Table clocks
The shading coil creates a phase difference by delaying the magnetic flux change in the shaded region.
The starting torque ratio is significantly lower than that of capacitor-start motors which can reach 200-300% of full-load torque.
D is correct тАФ The starting torque of a shaded pole motor is relatively weak, specifically between 0.2 and 0.3 times its full-load torque rating.
Always remember that shaded pole motors are only suitable for low-power applications (typically under 50W) due to their poor starting torque and low efficiency.