# How to connect a three-phase motor ?

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How to connect a three-phase motor?

Three-phase motors are widely used in solving a number of technical problems:.. They are indispensable in drives lathes, circular sawing machines, drilling machines, etc. The majority of three-phase motors are used inindustry, but sometimes you have to work and at home with them.

In this article, we'll show you how to connect the three-phase motor to a single-phase circuit.

## Three phases in one

The main problem that arises in this situation, to the user, - the absence of the three-phase network.Then you have to connect the three-phase motor to a single-phase 220 V. Of course, while there is a slight loss of power, but the engine turns out, one way or another, workable.

## rephasing capacitors

There are many ways to connect the three-phase motor in single phase, however, the simplest and therefore the most commonly used - a method that uses phase-shifting capacitor, which is powered by a third motor winding.

## Features inclusion

Before connecting the three-phase motor, see how connected to the motor winding.In that case, if they are connected in delta (see. Figure 1), the engine at the least to lose power, otherwise the engine power will be about 70% of capacity, he may provide when incorporated in a three-phase power supply circuit.

important point!In the picture you can see the terminal block, but in many cases, instead of them you will have to deal with bundles of wires, and to separate them from each other and understand which terminal applies each of them, you need to "ping" the contacts with the help of a special device,for example, a multimeter.As a result, the pairing is necessary to achieve a C1-C6, C2-C4, C3-C5 (see. Figure 2).

Connection To connect a three-phase motor in the network in addition to the engine itself, you will need two capacitor - starting and running, as well as a button.All these elements need to be soldered on the diagram (see. Figure 2).

## Calculation

capacitors To calculate the required nominal capacity of the run capacitor must use the formula - Cp = 4800 * I / U or Cp = 66 * P, where I, U, P - current, voltage, power circuit, respectively.Denomination starting capacitor is usually taken in more than three times the nominal working.By the way, if your circuit power less than a kilowatt, can do without the start-up capacitor.

## own or with professional help?

As you can see, the problem of connecting a three-phase motor in single-phase circuit is not that complicated, although a number of special tools you still need.Capacitors and key cost a penny, but the multimeter and soldering iron - it is a different story, so maybe better to call for help professional electrician?