21
|
Which type of capacitor is used in the two value
capacitor motor?
|
|
Electrolyte capacitor : Short duty
Oil capacitor : Continuous duty
|
22
|
How the optimum starting and running characteristics
is obtained in the two value capacitor motor?
|
|
Optimum starting and running characteristic
- The two capacitors are in parallel during starting
in the two value capacitor motor.
- When the motor speed reaches 75% of the
full load speed, the centrifugal switch open and only one capacitor of
continuous duty remains in the circuit.
|
23
|
What should be rating of starting capacitor as
compared to running capacitor in the two value capacitor motor?
|
|
The rating of starting capacitor ( Short duty rating
) is approximately 10 to 15 times that of running capacitor ( Continuous duty
rating ).
|
24
|
State the salient features of the two value
capacitor motor.
|
|
Salient
features of two value capacitor motor
- Noiseless operation
- High efficiency
- High power factor
- Overload capacity up to 125%
- Ability to start against heavy load
|
25
|
How the phase splitting is done in the shaded pole
induction motor?
|
|
The phase splitting in the shaded pole induction
motor is done by induction.
|
26
|
Which type of stator and rotor the shaded pole
induction motor consists of?
|
|
Shaded
pole induction motor
- Stator : Salient pole
- Rotor : Squirrel cage
|
27
|
Where the shading ring is placed in the shaded pole
induction motor?
|
|
Shading ring
- The stator of the shaded pole consists of salient
poles.
- The salient pole has small cut across the
lamination approximately one third distance from one end and shading ring is
placed on this cut.
|
28
|
State the direction of flux rotation in the shaded
pole motor?
|
|
Unshaded pole to shaded pole
|
29
|
State the salient features of the shaded pole motor.
|
|
Salient features
- Low efficiency ( 5% up to 35% )
- Low overload capacity
- Low starting capacity
|
30
|
State the applications of the salient pole motor.
|
|
Application
- Small toys
- Hair dryers
- Ventilators
- Electrical clocks
- Small fan
- Advertising display boards
- Phonograph turntables
|
31
|
Whether the direction of shaded pole motor can be
reversed? Why?
|
|
The direction of the shaded pole motor cannot be
reversed due to fixed position of shaded ring.
|
32
|
Describe the different types of repulsion motor.
|
|
Types of
repulsion motor
- Repulsion motor
- Compensated repulsion motor
- Repulsion start induction run motor
- Repulsion induction motor
|
33
|
Which type of construction does the repulsion motor
consist of?
|
|
Repulsion
motor
- Stator : Salient pole, non – distributed winding
- Rotor :
Similar to DC armature
- Commutator and carbon brushes
|
34
|
On which parameter the armature induced emf depends
in the repulsion motor?
|
|
The armature induced emf in the repulsion motor
depends upon the position of the short circuited brushes.
|
35
|
What is reason behind the name of motor called as
‘repulsion motor’?
|
|
Repulsion motor
- The rotor of the repulsion motor rotates due to
repulsion force between stator N pole and rotor N pole ( or stator S pole and
rotor S pole ) therefore it is called as repulsion motor.
|
36
|
On which parameter the starting torque of the
repulsion motor depends?
|
|
The starting torque of the repulsion motor depends
upon the amount of brush shift.
|
37
|
Which method is used to control speed of the
repulsion motor?
|
|
The speed control of the repulsion motor depends
upon brush shift.
|
38
|
Describe the function of compensating winding in the
compensated repulsion motor.
|
|
Function
of compensating winding
- Provides better speed regulation
- Improve power factor
|
39
|
Where the compensating winding is provided in the
compensated repulsion motor?
|
|
The compensating winding is provided in the inner
slot of the main pole and it is connected in series with armature winding.
|
40
|
How many brushes the compensated repulsion motor
consists of?
|
|
The compensated repulsion motor consists of two pair
of brushes.
|
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