How to connect the electric motor 380?
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Sometimes in everyday life you may need to applythree-phase motor, however, as a rule, a three-phase 380 V power supply "on hand" is rarely available. It is not necessary to get upset, because a three-phase motor can be connected to a single-phase 220 V power circuit. In this case, of course, the engine will lose a little in power, but in the absence of a three-phase supply network one can not choose. In this article, we'll show you how to connect a 380 V motor to a 220 V power supply.
Scheme with a working capacitor
If the motor power is less than1500 W, for its inclusion in addition requires a so-called working capacitor. One capacitor contact is connected to zero, and the second to the third output of the triangle (see Figure 1).
The first contact of the triangle must be wound in phase.
Scheme with operating and starting capacitor
If the motor power is more than 1500 W, forits inclusion requires not only a working but also a starting capacitor. It is connected in parallel with the working one, and two capacitors are separated by a button (see Figure 2).
Important! Do not connect 220 V motors to more than 3 kW!
Selection of capacitors
Formula for calculating the operating capacitor -Cp = 4800 * I / U, where I - current consumed by the motor, U - voltage of the network. In our case, the mains voltage is 220 V, and the current consumed by the engine can be specified in its passport.
The formula for calculating the starting capacitor is Cn = 3 * Cp.
An important point! When buying a capacitor, you must tell the seller not only the necessary nominal capacity obtained as a result of the calculation, but also the voltage that the capacitor must withstand, because if you take a low-voltage capacitor, it will simply burn out and ruin your engine.
Attention! After the engine is switched off, the capacitors retain their charge for a fairly long time, do not touch them at all!
As you can see, the task of connecting a three-phaseengine to a single-phase circuit is not so difficult, it can be handled without professional help, but we strongly recommend that you take precautions!
Read also the article How to connect the engine to 380 from the Technique section.