AC machines

2. Shaded-pole motors
• are the original type of AC single-phase induction motor
• basically a small squirrel-cage motor in which the
auxiliary winding is composed of a copper ring or bar surrounding a
portion of each pole
• direction of rotation is from the unshaded side to the shaded (ring)
side of the pole

3. Parts and Function
• Shaded pole
• magnetic pole in an electric motor or solenoid with a shading coil that
encircles a portion of the pole face
• Stator Winding
• the stationary winding in an electric motor, either for rotary or
linear
• End Bell
• the cap at the end of the motor that houses the rotor bearing.
• Stator
• is the stationary part of a rotary (electric) system or a Civil defense
siren
• Shaft Bearing
• is a mechanical component used to support an applied load, and
allow rotational or sliding motion between two or more parts
• Rotor
• is the non-stationary part of a rotary electric motor, electric
generator or alternator, which rotates because the wires and

4. Principle and Operation
•“Starting Torque”
•the function of the shaded poles
•Out of phase magnetic field and
shifting field

5. Speed/Load Characteristics
• have low starting torque, low efficiency, medium high
running current, low power characteristics, no capacitors,
no starting switch and are low cost
• found on small direct drive furnace blowers, window fans
and other fan applications found in the residential
community
• motors should NOT be used to replace OTHER TYPES of
single-phase motors, mostly due to the low torque and
efficiency
• output capability of a shaded pole motor will range from
"sub-fractional HP" i.e. 1/30 HP to a maximum of 1/4 or
1/3 HP

6. Application
•commonly found in applications that require
light-duty fans such as small window air
conditioners and exhaust fans used in rest
rooms
•also used in the paddlewheel-level sensor
•mostly employed in small instruments, toys,
small fans, electric clocks, hair dryers,
ventilators, circulators etc.
•best suited to low power household
application because the motors have low
starting torque and efficiency ratings

7. •compatible
applications include
hair dryers,
humidifiers and
timing devices
•other applications
include Microwave
oven fan, cooling
fan, can opener,
nebulizer, oxygen
concentrator,
blower, mechanical
and fan duty