Hi all! Today I will show you how to get a three-phase network from a regular single-phase 220 V network, and at no particular cost. But first, I’ll tell you about my problem that preceded the search for such a solution.
I had a powerful Soviet table saw (2 kW), which was connected to a three-phase network. My attempts to power it from a single-phase network, as is usually customary, were not possible: there was a strong power drawdown, the starting capacitors got hot, and the engine itself got hot.
Fortunately, at one time I spent due time searching for a solution on the Internet. Where I came across a video where one guy made a kind of splitter using a powerful electric motor. Next, he installed this three-phase network around the perimeter of his garage and connected to it all other devices requiring three-phase voltage. Before starting work, he came to the garage, started the dispensing engine and it worked until he left. In principle, I liked the solution.
I decided to repeat it and make my own splitter. As an engine, I took an old Soviet one with 3.5 kW of power, with star-connected windings.
Scheme
The whole circuit consists of just a few elements: a general power switch, a start button, a 100 uF capacitor and a powerful motor itself.
How does it all work? First, we supply single-phase power to the distributing motor, connect the capacitor with the start button, thereby starting it. Once the motor has spun up to the desired speed, the capacitor can be turned off. Now you can connect a load to the output of the phase splitter, in my case a tabletop circular and several more three-phase loads.
The body of the device - the frame is made of L-shaped corners, all equipment is fixed to a piece of OSB sheet. Handles for carrying the entire structure have been redesigned on top, and a three-pin socket is connected to the output.
After connecting the saw through such a device, there was a significant improvement in operation, nothing gets hot, there is enough power, and not only for the saw. Nothing growls or buzzes like it did before.
It is only advisable to take the distributing motor at least 1 kW more powerful than the consumers, then there will not be a noticeable drop in power under sudden load.
No matter who says anything about the sine not being pure or it will give nothing, I advise you not to listen to them. The voltage sine wave is clean and split exactly 120 degrees, as a result the connected equipment receives high-quality voltage, which is why it does not heat up.
The second half of the readers who will speak in the 21st century and the large availability of three-phase voltage frequency converters, I can say that my solution is several times cheaper, since the old motor is quite easy to find. You can even take one that is unsuitable for the load, with weak and almost broken bearings.
My phase splitter in idle mode does not consume so much: 200 - 400 W somewhere, the power of the connected tools increases significantly compared to the usual connection scheme through starting capacitors.
In conclusion, I would like to justify my choice of this solution: reliability, incredible simplicity, low costs, high power.
