Leading 3 Phase Motor Manufacturers

A 3-phase motor refers to an electrical-to-mechanical energy conversion mechanism that can convert an input of 3-phase electrical power to produce an output of mechanical energy.

What Is a 3-Phase Motor?

The motor consists of a rotating rotor and a stator. The stator winding receives the 3-phase supply of electrical energy and drives the rotor windings through electromagnetic induction.

How 3-Phase Motors Function

As the 3-phase stator winding receives a balanced supply of 3 phase electrical energy, a rotating magnetic field is produced in the motor. The rotating magnetic field rotates around the stator at a synchronous speed that is denoted by:

Synchronous speed = 120 f / P

Where f is the frequency of rotation and P is the number of poles.

Since the rotors carry a current and are in the magnetic field produced by the stator winding, they experience a mechanical force. The combined forces experienced on all the rotor conductors result in a torque which drives the rotors in the direction of the rotating magnetic field.

Types of 3-Phase Motors

There are two main types of 3-phase motors: the squirrel cage and the slip ring motors. The differences are mainly based on rotor windings.

Squirrel Cage Motor

The structure of this rotor assembly resembles the shape of a squirrel cage. The construction is simple and rugged and consists of a cylindrical laminated core rotor with slots on the external periphery. The squirrel cage has rotor bars instead of the expected rotor windings.

The bars are made of aluminum, copper, or brass. The rotor bars are welded or braced with the end rings for mechanical support. Normally the bars are short-circuited to add external resistance to the circuitry. This type of motor does not use slip rings or brushes, making construction simpler and very robust.

Slip Ring Motor

Slip ring induction motors are also referred to as wound motor rotors. It consists of a laminated cylindrical core with slots on the outside periphery and the rotor winding placed within them. The winding is wound so the number of poles in the rotor winding is equal to the stator winding. The end terminals of the rotor windings are then connected to the slip rings. An external resistance can be connected easily to the rotor circuit through the brushes and slip rings. This is important in controlling the speed and torque of the motor.

Applications of 3-Phase Motors

Slip ring motors are usually used for devices like plunger pumps, cranes, conveyors, crushers, or elevators. In addition, slip ring induction motors are commonly used for loads that need a very high initial torque and usually for cases where the starting current is low. They are also ideal for the carriage of loads that require speed control and altering the spin rate. Squirrel cage motors have a normal initial torque with a high starting current. The motors are commonly used in appliances like electric blowers, fans, and centrifugal pumps.

Advantages of 3-Phase Motors

• 3-phase motors have a simple and rather rugged construction. Once set up, they do not require extensive maintenance and are therefore less expensive.
• 3-phase motors have very high efficiency and a favorable power factor. Thus, for a given load, they draw fewer volt-amperes.
• 3-phase motors also have a self-starting torque.
• These types of motors, if accurately set, can be left out to work automatically without the need for human control but rather scheduled maintenance after a specified duration.
• Typical examples are the case of conveyor belts and building elevators that can function automatically without constant control.
• Single-phase systems can yield pulsating power, but 3-phase systems yield a more stable power supply.

Choosing the Correct 3-Phase Motor Supplier

For the most productive outcome when purchasing a 3-phase motor from a 3-phase motor supplier, it is important to compare several 3-phase motor suppliers using our directory of 3-phase motor companies. Each 3-phase motor supplier has a business profile page highlighting their areas of experience and capabilities, along with a contact form to directly communicate with them for more information or request a quote. Review each 3-phase motor business website using our proprietary website previewer to get an idea of what each company specializes in. Then, use our simple RFQ form to contact multiple 3-phase motor companies with the same form.