Which DC motors is preferred for elevators?
Which D.C. motor is preferred for elevators?
- A. Shunt motor.
- Series motor.
- Differential compound motor.
- Cumulative compound motor.
Which motor is preferred in elevators?
Lifts are preferred by AC slip ring or DC compound motor. In case of single phase installation, the commutator motors are preferred. Variable Frequency drive electronic controls are used in the latest lift designs.
Why is a DC motor preferred?
Higher Starting Torque Than AC
DC motors have higher starting torque than their AC counterparts, making it easier to get things moving. … Without a load to slow them down, DC motors can burn out quickly. For applications that need constant low-speed or variable-speed torque, DC motors are ideal.
What is the main advantage of a DC motor?
The primary advantage of the DC motor is that it can develop constant torque over a wide speed application. Power supply is an important consideration in the application of DC motors. The most common way to provide DC voltage to a motor from an AC line is through the use of an electronic drive.
Which DC motor has maximum self loading property?
Series motor. Shunt motor. Cumulatively compounded motor.
Which motor has the poorest speed control?
1. Which of the following DC motor has the poorest speed control? Explanation: DC series motor at no load condition gives infinite speed ideally. Practically it will damage all the armature circuit.
What will happen when the DC motor is connected to AC supply then?
1. What will happen if DC shunt motor is connected across AC supply? Explanation: In case of parallel field connection, it won’t rotate at all and will start humming and will create vibrations, as a torque produced by positive and negative cycle will cancel out each other. DC motor will be heated up and it may burn.
What are the disadvantages of DC motor?
Disadvantages of DC motors
- High initial cost.
- Increased operation and maintenance cost due to the presence of commutator and brush gear.
- Cannot operate in explosive and hazard conditions due to sparking occur at brush (risk in commutation failure)
Which is the DC motor preferred over AC motor?
Because DC motors have higher starting torque compared to AC motors, they are preferred for applications like electrical traction. They are considered ideal for dealing with heavy loads for starting conditions in machines such as locomotives and cranes.