# How the magnetic field rotates in an AC motor?

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The rotating magnetic field is produced radially around the rotor by the varying currents in the stator windings. The rotating magnetic field induces eddy currents in the squirrel cage’s vertical bars causing it to rotate. The rotation of the rotor and magnetic field are asynchronous.

## How does an AC motor rotate?

In an AC motor, there’s a ring of electromagnets arranged around the outside (making up the stator), which are designed to produce a rotating magnetic field. … The coils are energized in pairs, in sequence, producing a magnetic field that rotates around the outside of the motor.

## What is rotating magnetic field in induction motor?

A rotating magnetic field is a magnetic field that has moving polarities in which its opposite poles rotate about a central point or axis. … Rotating magnetic fields are often utilized for electromechanical applications, such as induction motors and electric generators.

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## What is the speed of rotating magnetic field?

Speed is important to the rotating magnetic field of an AC motor. It is known as “synchronous speed.” This speed is calculated by dividing 120 times the frequency (F) by the number of poles (P). As an example, the synchronous speed for a 2-pole motor operated at 60 Hz is 3,600 RPM.

## Why does the rotor of the induction motor rotate in the same direction as the rotating magnetic field?

The polarity of these rotor poles is such that they are attracted to the poles of the stator’s magnetic field, so they cause the rotor to follow the rotating magnetic field around in the same direction as the rotating magnetic field in the stator.

## What are the 6 parts of an electric motor?

These six components include:

• 1) The Rotor. The rotor is the moving part of your electric motor. …
• 3) The Bearings. The rotor in your electric motor is supported by bearings, which allow it to turn on its axis. …
• 4) The Windings. …
• 5) The Air Gap. …
• 6) The Commutator. …
• What Do All of These Components Have in Common?

## Is my motor AC or DC?

Look for the stator core construction and rotor. If there is no commutator, then it is a AC motor. If there is a commutator and brushes, it may be either a DC motor or an AC commutator motor (Universal motor).

## What are the advantages of rotating magnetic field?

• Rotating field type alternator is used in big power plants because of its high power rating.
• As the armature is stationary power can be get without using brush or slip rings.
• We can insulate the conductor as the armature is stationary.
• Insulation can be kept high in fixed armature type alternator.

## How do you rotate a magnetic field?

The rotating magnetic field is produced by the three-phase current of the stator in the actual three-phase induction motor. It can be replaced by permanent magnets in a permanent magnet synchronous motor. The three-phase windings of the inner stator are spaced 120° electrical degrees apart.

## Why do motors rotate?

Large AC motors (used in things like factory machines) work in a slightly different way: they pass alternating current through opposing pairs of magnets to create a rotating magnetic field, which “induces” (creates) a magnetic field in the motor’s rotor, causing it to spin around.

## What is slip speed?

The speed at which the induction motor work is known as the slip speed. … The difference between the synchronous speed and the actual speed of the rotor is known as the slip speed. In other words, the slip speed shows the relative speed of the rotor concerning the speed of the field.

## What is 120 in motor speed formula?

The equation for calculating synchronous speed is: S = 120 f/P speed = constant (120) times frequency of power source (60 Hz) divided by number of poles used in the motor (P). Where does the 120 come from and what units does it have? There is RPM on one side and Cycles/second divided by #of poles on the other.

## What two factors determine synchronous speed?

The frequency of the power supply and the number of poles of the machine determine the synchronous speed. A synchronous motor is one in which the rotor turns at the same speed as the rotating magnetic field in the stator.

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## When a motor is short circuited what causes the motor to still rotate?

A magnetic field with the poles facing out is produced in the rotor due to the stator induced current. This causes the rotor (motor shaft) to rotate. As long as the stator is supplied to a stable voltage supply, the motor shaft will continue to rotate. During a short circuit condition the system voltage will decay.

## Which type of motor has high starting torque?

DC Series motor has high starting torque. We can not start the Induction motor and Synchronous motors on load, but can not start the DC series motor without load. DC motor has high starting torque.In a series motor the same current flows through the armature and the field winding.

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