Types of Crane Duty Motors
The crane motors are duty type rated for developing high starting torque with low starting current. The motors are designed to withstand stresses due to frequent starts/stops and reversals. Also, a rapid acceleration is achieved by high pull out torque/rotor inertia ratio.
Why DC motors are used in cranes?
The starting torque of the DC series motor is proportional to the square of the armature current. … That is why DC series motor is capable to produce high starting torque, and it is preferred for driving heavy loads. The high inertia loads like cranes need a high starting torque. The DC series motor is used in cranes.
Which DC motor is preferred for crane and hoist?
Which DC motor is generally preferred for cranes and hoists? Explanation: DC series motor is used where high starting torque is required, thus in cranes and hoists DC series motor is used widely. Torque-speed characteristics of DC series motor suits perfectly to these applications.
Why 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.
How do you change the direction of a DC motor?
The direction of rotation of DC series motor may be reversed by changing the polarity of either field or the armature winding.
What is electric braking of DC motor?
The electric braking of a DC motor is of three types, (i) Rheostatic or dynamic braking, (ii) Plugging or reverse current braking and (iii) Regenerative beaking. … (ii) Plugging or Reverse current braking: In this method, armature connections are reversed and hence motor tends to run in opposite direction.
Which motor is used in traction?
The motors used are induction or asynchronous motors designed to have characteristics suitable for traction. The speed and torque of the motor are controlled by varying the frequency, voltage and current applied to the stator coils. Motors for a typical locomotive would be in the range 400 to 600 kW.
Which motor is used in lift?
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.
How do you choose a crane motor?
Most vital and primary technical consideration for selection of the motor for any particular application is the torque required by the load during starting and acceleration periods, especially the relationship between the maximum torque or breakdown torque generated by the motor and the start-up torque or locked rotor …
Which motor is comfortable within the crane?
Synchronous motor. For crane travel, trolley travel and boom hoist of traveling crane requires high starting torque and constant speed in operation. Hence slip ring induction motor is preferred.
What type of motors are there?
Types of Electric Motors
- AC Brushless Motors. AC brushless motors are some of the most popular in motion control. …
- DC Brushed Motors. In a DC brushed motor, brush orientation on the stator determines current flow. …
- DC Brushless Motors. …
- Direct Drive. …
- Linear Motors. …
- Servo Motors. …
- Stepper Motors.
Which DC motor is used in lift?
AC slip ring or DC compound motors are prefer for lifts. Shunt type commutator motors are preferred in case of single phase installation. The latest lift designs use 3-phase induction motors with variable frequency drive electronic controls.
Which motor is used in mixer?
For a mixer grinder, we use UNIVERSAL MOTOR. This motor is used in other home appliances too like refrigerators, fans, etc. The universal motor is an electric motor that can operate on either AC or DC power and uses an electromagnet as its stator to create the magnetic field.
What is AC motor & Types?
Operating principles. The two main types of AC motors are induction motors and synchronous motors. The induction motor (or asynchronous motor) always relies on a small difference in speed between the stator rotating magnetic field and the rotor shaft speed called slip to induce rotor current in the rotor AC winding.
Which motor is used in trams?
Dc motor (Ma) and induction motor (Mc) are currently manufactured and used in 105 N tram drive, their parameters are available. Dc motor (Mb), brushless motor (Me) and slip-ring motor (Md) pa- rameters have been determined by analysis.
Do trains use AC or DC?
Direct current, either directly supplied, or converted from AC onboard a train, is the most commonly used. This is because, according to railsystem.net, “DC consumes less energy compared to an AC unit for operating the same service conditions.
Are locomotives AC or DC?
Rectifier locomotives, which used AC power transmission and DC motors, were common, though DC commutators had problems both in starting and at low velocities. Today’s advanced electric locomotives use brushless three-phase AC induction motors.
What are the applications of DC motor?
Application of DC Series motor
- Air compressor.
- Winching system.
- Electric traction.
- Hair drier.
- Vacuum cleaner and in speed regulation application.
What are the types of DC motor?
4 Types of DC Motors: An Introduction
- Permanent Magnet DC Motors. The permanent magnet motor uses a permanent magnet to create field flux. …
- Series DC Motors. In a series DC motor, the field is wound with a few turns of a large wire carrying the full armature current. …
- Shunt DC Motors. …
- Compound DC Motors.
What happens during braking of DC motor?
Dynamic braking occurs when two things happen. One, it’s disconnected from the power supply, and two, the braking resistor is quickly connected across the armature. The kinetic energy that’s stored in the motor gets converted into electrical energy that turns into heat.
Can you reverse a DC motor?
DC motors, like AC motors, can be configured to turn in either direction. Their direction can be easily controlled by inverting the polarity of the applied armature voltage by reversing the armature leads.
How do you control the speed and direction of a DC motor?
Thus, the speed of a DC motor can be controlled in three ways:
- By varying the supply voltage.
- By varying the flux, and by varying the current through the field winding.
- By varying the armature voltage, and by varying the armature resistance.
What will happen when the DC motor is connected to AC supply?
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.