ELECTRONIC PRODUCTS ASSEMBLY AND SERVICING
EPAS
MAINTAIN AND REPAIR
CONSUMER ELECTRONICS
MOTOR CONTROLLED APPLIANCES
MANNASEH A. LINA
TVL-11
LESSON OBJECTIVES:
• To identify the external and internal parts of an electric
fan and explain its functions.
• Measure the resistance of motor winding using an
Ohmmeter.
WHAT IS AN ELECTRIC FAN?
•It is a type of electronic
appliances that is run by an
electronic motor.
WHATS THE PURPOSE OF AN ELECTRIC FAN?
• To convert electrical energy to mechanical
energy.
• To make consumers feel comfortable during
hot seasons or summer days.
EXTERNAL PARTS OF AN ELECTRIC FAN
EXTERNAL PARTS OF AN ELECTRIC FAN
1. Base. Supports the entire mechanism. Usually where you
will find the on-off switch (regulator), which may have 2
or 3 optional speeds - low, medium, and high.
2. Motor Housing. Contains the electric motor - the rotor
to which the blade assembly is attached.
EXTERNAL PARTS OF AN ELECTRIC FAN
3. Blade/Impeller assembly. Cuts the air and
pushes it forward.
4. Blade guard. Prevents curious fingers or
kitty cats from suffering injury.
5. Power cord with plug. Connects to your
home’s electric service power supply.
INTERNAL PARTS OF AN ELECTRIC FAN
1. Electric Motor - It is the main part of the electric fan
that produces mechanical energy to make the propeller
rotate.
2. The Stator - It is a non movable part of the electric
motor that provides electro magnetic energy to the rotor.
INTERNAL PARTS OF AN ELECTRIC FAN
3. Rotor – It is the movable part of the electrical
motor that rotates.
4. Copper Winding / Coil - It is a set of copper
wire that supplies electricity in the stator and rotor.
INTERNAL PARTS OF AN ELECTRIC FAN
5. Capacitor - The capacitor is used not only to
start the fan but also to make it spin. In simple
words, the capacitor creates a magnetic flux
(torque) which makes the fan rotate.
6. Thermal Fuse - a thermal fuse or thermal cutoff
is a safety device which open circuits against over
heat. It detects the heat caused by the over-current
due to short circuit or component breakdown.
INTERNAL PARTS OF AN ELECTRIC FAN
7. Selector Switch /Control Switch - It is a part of
electric fan that can intensify the produce air for
the consumers.
Push button switch
Rotary switch
MOTOR RESISTANCE
 The Higher Resistance means a Low Current
which will result slow rotation of the propeller.
• The Lower Resistance means a Higher Current
which will result in fast rotation of the propeller
FAN SPEED CONTROL
 Since that the no.1 in the selector switch has a
slow rotation of rotor it means that the
resistance needed is high.
 No.2 in the selector switch will have a
moderate resistance and the no.3 has a lowest
resistance
SCHEMATIC DIAGRAM
MOTOR TERMINALS /TEST POINTS
• There are six (6) colored wires in an electric fan motor.
These wires are connected to the winding or coil inside
the stator. These are called the Test points where you can
do resistance measurements of the winding/coil
• (Below is the pictorial and schematic diagram)
DIAGRAM
Pictorial
Wire terminals
Schematic
There are six (6) Test points
HOW TO MEASURE RESISTANCE OF MOTOR
WINDING/COIL
Instructions:
 Using a digital multimeter / tester, measure the
resistance of the winding by placing the test probes
between the two the Test points.
 Connect the multimeter test probes between two
test points and examine the resistance reading.
(As shown in Fig. 1.1)
Fig. 1.1 Testing the coil resistance by the
test points.
Testpoint
1
Testpoint
2
Resistance
Reading
468 Ohms
ACTIVITY 1
• Given an electric fan motor
• Measure the resistance between each Test Point. Complete the table by writing the
resistance measured between each Test points. Record each resistance reading.
Testpoint
1
2
3
4
5
Testpoint
2
3
4
5
6
Resistance
Reading