What Is A 3-Phase Motor – Everything You Should Know

Three phase motors are the type of AC motors that work on alternating current. These motors are widely used in both high-grade and low-volume industries for accurate operations. 3-phase electric motors are available as 3 phase synchronous motors and three-phase asynchronous motors.

What Is a 3-phase motor?  The motor works on three phases of electrical power connection to provide high strength, efficiency, and reliability. 3-phase motors have an advanced working mechanism in which the rotor rotates around the output shaft to generate mechanical energy. Xinnuo Motor is the leading electric motor manufacturer in China that supplies premium quality motors worldwide.

Figure 1- 3-phase Motor

Figure 1: 3-phase motor

 In this article, we will discuss various types, advantages, and applications of 3 phase electric motors.

Types of 3 phase motors:

The three phase electric motors can be categorized into three general types based on their specifications and working principles. Let’s uncover the three major types of 3 phase motors.

Slip ring induction motor:

The Slip Ring induction motor is prominent in types of 3 phase motors because the speed of the motor and rotor is not synchronized. These motors contain a wound-type rotor, cylindrical steel core, and slip rings for connections. The slip rings are connected to a 3-phase external power source. These motors have star winding for extraordinary efficiency and resistance. These motors have high starting torque and speed control.

Figure 2- Slip Ring Motor

Figure 2: Slip Ring Motor

Squirrel cage induction motor:

The squirrel cage induction motor is the most commonly used 3-phase asynchronous motor. The rotor of this motor looks like a squirrel cage; therefore, it is called a squirrel cage motor. Stator induces rotating electromagnetic fields to produce power in the rotor. The rotor and stator windings together produce high torque in the squirrel cage motor. These motors are widely used in domestic and industrial applications.

Figure 3- Squirrel Cage Motor

Figure 3: Squirrel cage motor

Permanent magnets three-phase motor:

Another widely used type of 3 phase motor is permanent magnet motors are AC synchronous three phase’s motors that produce magnetic fields through the magnet. The rotor provides high torque and working efficiency. The permanent magnet 3 phase motors have a brushless structure that reduces internal friction to ensure smooth operation. The permanent magnet synchronous three-phase motor is utilized in various industrial operations for dynamic and continuous performance.

Advantages of 3 phase induction motor:

3 phase motors are superior quality motors with exceptional features. Some of the extraordinary advantages of 3-phase motors are as follows;

●        Efficiency:

The 3 phase electric motors have high standard efficiency. The efficiency rate of a 3 phase motor is 85% to 96%. The full load efficiency of these motors is high because these motors operate on a 3-phase power supply. Moreover, three-phase motors provide maximum torque rate and rpm (revolution per minute).

●        Power Output:

The power output and PF rating of 3 phase induction motors are high and reliable. These motors are self-starting and provide constant power. Moreover, the size of 3 phase motors is bigger; therefore, the output is more advanced.

●        Reliability:

The three phase motors are made with 100% raw material and stainless steel. These motors can operate effortlessly in harsh climate conditions; therefore, they are reliable and durable electric motors. Moreover, these motors are protected with high-grade protection and insulation class which further ensures long life.

●        3 phase motor price:

The price range of 3-phase motors is affordable for both industrial and domestic applications. The price of these motors is comparatively higher than single-phase motors, but the quality pays off.

Applications of 3 phase motor:

Due to advanced features and specifications, 3-phase motors are widely used in several industries. Some typical applications of three-phase induction motors are as follows;

  • Cutting and lathe machines: Three phase motors are widely implemented in the cutting, grinding, lathe, and pressing machines for accurate and reliable performance in the woodcutting industry.
  • Flour Mills: 3 phase electric motors are also used in the flour mills for grinding grains.
  • Lifting Industry: 3-phase electric motors have high load capacity; therefore, these motors are used in conveyors, compressors, elevators, and cranes.
  • Pumping Industry: 3-phase electric motors are also applied in the pumps, blowers, and propulsion machinery.

Xinnuo Motor also offers a wide range of industrial motors, single phase motors, and OEM motors.


If you are looking for a reliable and efficient motor, 3-phase motors are a perfect choice. Three phase electric motors are robust, economical, and self-starting. These motors work efficiently in severe climate conditions without malfunctions. Xinnuo Motor also provides 100% customization of induction motors. For further details, contact us.

What is a 3-phase motor? -FAQ

1: Can a 3 phase motor run on a single phase?

Yes, you can run a three-phase electric motor on a single-phase power supply with the VFD (variable frequency device). However, connecting a 3 phase electric motor with a VFD and then to a single phase supply can impact the overall efficiency and rated capacity of the motor.

2: Why 3 phase motor is self-starting?

Three phase motors are self-starting because they do not demand additional power supply for producing initial torque. Unlike single phase motors, three-phase motors work on their own.

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