What is a three-phase motor?

Are you looking for a three-phase motor? We know that choosing which electric motor to use can be complicated: between mounting types, power, rotational speed, and other characteristics, the choice of an electric motor is important as it must meet your expectations and your application. That's why, in this article, we explain what a three-phase motor is.

What is the principle of an electric motor?

Before explaining what a three-phase motor is, we want to tell you about how an electric motor works.

An electric motor is equipment that converts electrical energy into mechanical energy to drive industrial, agricultural, or domestic machines. This three-phase electric motor consists of several components.

We have the stator, which is the fixed part of the motor and consists of a winding.

Then, we have the rotor, which is the rotating part and is composed of a coil, electromagnets, or permanent magnets.

The electric motor of an industrial, agricultural, or domestic machine operates from an electrical power supply. Once the 380V electric motor is powered, the electrical energy will supply the stator coil and then allow the rotor to rotate.

This stator has magnetic poles composed of North and South poles. When these two poles are in the presence of each other, an attraction is created. Thus, when electrical energy enters, the two poles attract and reverse as they cannot stick together, thus creating a magnetic field.

This magnetic field will allow the rotor to rotate, thus generating mechanical energy that enables the electric motor to function.

An electric motor can have a different number of poles. 2 poles in the electric motor correspond to a rotor reaching 3000 rpm. 4 poles are equal to 1500 rpm, 6 poles correspond to 1000 rpm, and finally, 8 poles are equal to 750 rpm.

This rotational speed will define the size of your electric motor, which depends on your application.

We have just explained the principle of an electric motor. There are either single-phase electric motors or three-phase electric motors. We will now explain what a three-phase motor is.

What is a three-phase motor?

We talk about a three-phase motor because it operates with a three-phase power supply voltage. This consists of 3 phases and is mainly used in the industrial and agricultural sectors.

In contrast, a single-phase power supply voltage is primarily used by individuals for domestic applications.

A three-phase electric motor is used by many manufacturers for the following reasons: it is robust, economical, durable, and has a standardized design.

You can find our article on the use of a three-phase motor here for more information.

For industrial and agricultural applications with large machines, we will rather use a three-phase motor; it is perfectly suited for these applications because they need a powerful electrical current to function.

Each motor has a different rotational speed, a different mounting, a different power, etc. This is why, before choosing which electric motor to use, you must first define your needs.

What is a three-phase motor? This is the explanation we have just given you. There are two elements left to define: what are the different mounting types? An asynchronous electric motor or a synchronous electric motor?

A three-phase asynchronous motor or a three-phase synchronous motor?

The difference between a three-phase asynchronous motor and a three-phase synchronous motor is located in the rotor, a component whose explanation is at the beginning of this article.

Regarding a synchronous motor, the rotor has the same rotational speed as the magnetic field. As for the asynchronous motor, the rotor has a rotational speed that is slower than the magnetic field.

An asynchronous motor has a rotor consisting of a winding, while a synchronous motor has a rotor composed of permanent magnets or electromagnets.

The difference between a three-phase asynchronous motor and a three-phase synchronous motor shows the important role of the following components: the rotor and the stator, explained previously.

What are the different mounting types?

The mounting of a three-phase motor depends on its installation. There are 5: B3, B5, B14, B34, and B35.

B3: foot mounting

B5: flange mounting with smooth holes

B14: flange mounting with tapped holes

B34: foot and flange mounting with tapped holes

B35: foot and flange mounting with smooth holes

Our article on "What is a three-phase motor?" is finished, and we hope it has answered your questions.

Choosing the right electric motor can seem complicated. In this choice, there are advantages and disadvantages. That's why you need to determine your needs and your environment beforehand. We invite you to read our article to learn about the importance of having a good electric motor manufacturer.

If you need more information, do not hesitate to contact us and browse our blog, which can guide you in your choice of electric motor.