Applications of Different Types of Motors
D.C. Series Motor
It has high starting torque and a variable speed range. Therefore, it is used for heavy-duty applications such as:
- Electric locomotives
- Steel rolling mills
- Hoists
- Lifts
- Cranes
D.C. Shunt Motor
It has medium starting torque and a nearly constant speed. It is used for driving constant-speed loads like:
- Lathes
- Vacuum cleaners
- Wood-working machines
- Laundry washing machines
- Elevators
- Conveyors
- Grinders
- Small printing presses
Three-phase Synchronous Motor
This is a constant-speed motor suitable for variable loads. Common applications include:
- Ammonia and air compressors
- Motor-generator sets
- Continuous rolling mills
- Paper mills
Squirrel Cage Induction Motor
Known for its simple and rugged construction, it has high overload capacity and nearly constant speed but poor starting torque. Applications include:
- Water pumps
- Tube wells
- Lathes
- Drills
- Grinders
Double Squirrel Cage Motor
This motor has high starting torque and large overload capacity. It is used in:
- Compressor pumps
- Reciprocating pumps
- Large refrigerators
- Crushers
- Boring mills
- Textile machinery
- Cranes
- Punches
- Lathes
Slip-ring Induction Motor
It has high starting torque, large overload capacity, and adjustable speed (up to 50% variation). It is used in:
- Lifts
- Pumps
- Winding machines
- Printing presses
- Line shafts
- Elevators
- Compressors
Single-phase Series Motor
With high starting torque and wide speed control range, this motor is ideal for small domestic appliances like:
- Refrigerators
- Vacuum cleaners
Repulsion Motor
It offers high starting torque and wide speed control. It is used in:
- Coil winding machines
- Applications requiring adjustable yet constant speed under high load
Capacitor-start Induction-run Motor
This motor runs at a constant speed and offers high starting torque. It is generally used in:
- Compressors
- Water pumps
- Refrigerators
Capacitor-start-and-run Motor
Similar to the above, but with better power factor and efficiency. It is used where: Quiet operation is essential
Conclusion
Different motors serve different purposes based on torque, speed characteristics, and load requirements. Understanding the properties and typical applications of these motors helps in selecting the right motor for industrial or domestic applications.
MCQs Based on Motor Applications
-
Which motor is best suited for electric traction like locomotives?
a) D.C. Shunt Motor
b) Squirrel Cage Induction Motor
c) D.C. Series Motor
d) Synchronous Motor
➤ Answer: c) D.C. Series Motor -
Which motor is used where constant speed operation is required regardless of load variation?
a) Slip-ring Induction Motor
b) Repulsion Motor
c) Synchronous Motor
d) D.C. Series Motor
➤ Answer: c) Synchronous Motor -
Which of the following motors is most commonly used in ceiling fans?
a) Capacitor-start-and-run Motor
b) D.C. Series Motor
c) Squirrel Cage Induction Motor
d) Slip-ring Motor
➤ Answer: a) Capacitor-start-and-run Motor -
Which motor has poor starting torque but runs at almost constant speed?
a) Repulsion Motor
b) Squirrel Cage Induction Motor
c) D.C. Shunt Motor
d) Slip-ring Motor
➤ Answer: b) Squirrel Cage Induction Motor -
Which motor is suitable for high starting torque and smooth acceleration?
a) D.C. Shunt Motor
b) Single-phase Series Motor
c) Double Squirrel Cage Motor
d) Synchronous Motor
➤ Answer: c) Double Squirrel Cage Motor