12. Motors Flashcards
1
Q
What are the different types of motor?
A
- Series Universal
- Induction motor
- Three phase wound rotor motor (slip ring motor)
- Synchronous Motors
- Split Phase
- Capacitor start
- Capacitor Start capacitor run
2
Q
Applications of a Series Universal motor.
A
- Portable drills
- Hair dryers
- Grinders
- Table fans
- Kitchen appliances
3
Q
Advantages of Series universal motors
A
- High running speeds are available.
- Provides more power for its size than any other AC motor.
- High starting and running torque.
- Relatively cheap to produce.
4
Q
Disadvantages of Series Universal Motors
A
- Heat is produced where the carbon brushes make contact with the commutator.
5
Q
Applications of Three Phase induction motors
A
- Industrial Pumps
- Industrial drives
- Drilling machine
- Cranes
- Lifts
6
Q
Advantages of Three phase induction motors
A
- Simple construction (cheap)
- Self starting
- Mechanically strong
- High efficiency and reasonable PF.
- Low maintenance requirements.
7
Q
Disadvantages of Three phase induction motors
A
- Constant motor speed which cannot be easily changed.
- Always operate under lagging power factor.
- Poor power factor under light load conditions.
- Poor starting torque
8
Q
Applications of Three phase synchronous motors
A
Often used where precise constant speed is required.
- Clocks
- Timers
- Crushers
- Grinding mills
- Belt conveyors
9
Q
Advantages of Three phase synchronous motors
A
- High efficiency
- Ability to control the PF.
- Constant speed under load variations.
- High torque
- Low starting currents
- Low operating and maintenance costs.
10
Q
Disadvantages of three phase synchronous motors
A
- Cannot be started on load
- Zero starting torque
- Cannot be used for variable speed.
- Need a DC supply.
- Not self starting.
- Can’t be used for frequent starting
11
Q
Applications of a Split phase induction motor
A
- Used with light starting conditions
- Agitators
- Tumble dryers
- Washing machines
12
Q
Disadvantages of a Split phase induction motor
A
- Low starting torque.
- Speed can’t be controlled due to the centrifugal switch
13
Q
Applications of a capacitor start motor
A
- Applications involving a hard starting load.
- Compressors
- Refrigerators
14
Q
Advantages of capacitor start motor
A
- Quiet running
- Good starting torque
- Good power factor
15
Q
Applications of capacitor start capacitor run motor
A
- High pressure water pumps
- Auger motors
- Vacuum pumps
- other high torque applications
