Single-Phase Motor: Everything you need to know for your Industrial and Domestic Applications

The single-phase motor plays a crucial role in many applications, whether industrial or domestic. Do you truly understand the single-phase motor?

In this article, you will find a detailed explanation of the single-phase motor, as well as recommendations for its use and purchase.

What is a single-phase motor?

The single-phase electric motor, also known as a 220V electric motor, is designed to operate with a single alternating current power source. Unlike three-phase motors, which require three current phases, single-phase motors only need one phase. This makes them simpler and more compact, suiting them for a wide range of industrial and domestic applications.

What applications can a single-phase electric motor be installed on?

Single-phase motors are generally used in a multitude of industrial and domestic applications due to their versatility and very simple operation.

- Pumps or compressors: They can power water pumps, pumping systems, and air compressors.

- Machine tools.

- Air conditioning and heating systems: Compressors, fans, heat pumps.

- Air compressors and car lifts in automotive garages.

The versatility, compatibility with domestic electrical networks, and cost-effectiveness of single-phase motors are highly valued.

Is it possible to connect a three-phase motor to a single-phase supply?

It is possible to connect a three-phase motor to a single-phase supply. However, some modifications need to be made for it to function correctly. Two methods exist, each with its advantages and disadvantages:

- Using a permanent capacitor: A capacitor is added between one of the phases and the motor terminals, allowing it to start and operate. This solution is simple and quick to implement. Nevertheless, it is commonly accepted that this solution leads to a 30% reduction in starting torque. To determine which capacitor to use, you need to take the horsepower (hp) of your motor and multiply it by 50. This will give you the capacitor's capacitance in microfarads (µf).

- Using a frequency inverter: This will convert the single-phase current into three-phase current, which is then sent to the motor. It also allows for varying the motor speed. Unlike the permanent capacitor, the frequency inverter will not cause any power loss to the motor. However, they are more expensive than all other systems.

Single-phase motor: Difference between permanent capacitor and dual capacitor.

Capacitors play an important role in the operation of single-phase motors. Two types of capacitors exist: permanent capacitors and dual capacitors.

The permanent capacitor is continuously connected to the motor (both during starting and continuous operation of the motor). It has a maximum capacity of 100µf (microfarads).

The dual capacitor consists of a permanent capacitor and a starting capacitor. The starting capacitor will be used exclusively to start the motor, which will provide a high starting torque. After starting, it will disconnect. Its capacity is higher than that of the permanent capacitor (between 50μf and 400μf).

The type of capacitor will be determined by the motor's power, but especially by the application it will be used on, and according to the expressed needs.

You can find our article for explanations on how to connect a single-phase motor to your application.

Where to buy a 220V single-phase motor?

Dymatec Industries, a supplier of single-phase electric motors, has a wide range of motors available in stock. Are you a professional or an individual? You can order directly on our website. Your order will be prepared within the hour.

We are located in Cambrai, in the Hauts-de-France region. You have the option to pick up your motor directly at the store, or we can ship it the same day for delivery within 24-48 hours.

Do you have an electric motor but don't know how to identify it? Don't panic, you can send an email to contact@dymatec-industries.com or call 03.27.74.11.65, an advisor can help you find the right solution for your needs.