How to find the beginning and end of the motor winding

So... You have a three-phase motor. But for some reason, the ends of the windings are not connected either in a triangle or in a star.

There are 6 ends in front of you. Ultimately, you need to somehow connect them together so that the electric motor starts working. We have decided on the task - let's move on to action.

At the end of the article, as always, you can watch the video version of this topic on my YouTube channel

So that we can connect the windings into a star or a triangle, we need to find the beginnings and ends of the windings.

As a test subject, we will have this small three-phase motor:

With its characteristics, you can familiarize yourself by looking at this plate:

First of all, we need to find each winding and hang a tag on the corresponding ends. We do this with a conventional tester switched to the resistance measurement mode. This is probably the easiest step in the process.

We connect one of the probes to any output from the engine, and the second in turn touch the remaining five wires. One of the pairs will show some resistance (units or tens of ohms). This is our first winding. We hang tags with the letter "A" on the ends of the wire.

In the same way, we call the remaining 4 wires. We find two more pairs. On one of them we hang a tag with the letter "B", on the other - with the letter "C"

Now we assemble the circuit, according to this sketch:

We take one wire (any) from the “A” winding and one from the “B” winding. We connect them. To the remaining free ends, we connect a voltmeter. The measurement limit is 10-20V AC voltage.

We connect an alternating voltage source to the ends of the winding "C". I use 12 volts - it's safer for me and for the engine.

So ... If, when applied to the "C" winding, our voltmeter did not record anything. So we connected the winding "A" and "B" in the opposite direction - i.e. wrong (in the diagram above in the text). Swap the ends of one of the windings. For example - at the winding "B":

We again apply voltage to the “C” winding and ... we see that the voltmeter showed a certain value. If we apply 12 Volts, then we will “catch” in the region of 3-5 Volts.  

If there is voltage at the free ends of the windings "A" and "B" connected in series, then the windings are connected correctly. And now we need to draw numbers on the tags.

I suggest doing it like in the diagram above:

"A1" - at the point of connection to the voltmeter

"A2" - at the point of connection with the winding "B"

"B1" - at the point of connection with the winding "A"

"B2" - at the point of connection to the voltmeter

We will conditionally assume that all letters with the number "1" are the beginning of the windings, and with the number "2" - the ends of the windings.

We figured out the windings "A" and "B". Now you need to find out where the beginnings and ends of the winding "C" are.

We connect it according to the above technology with any of the windings (for example, with "A"). We supply our 12 Volt variables to the remaining winding (“B”).

As soon as we catch voltage at the free ends of the windings “C” and “A” connected in series, you can immediately add numbers to the “C” tags. 

It is most convenient to start from the point of connection of the windings "C" and "A":

- If at this point the winding "A" with the number "1", then at "C" we add "2"

- If "A" with the number "2", then "C" will have "1".

Now you can connect the windings in a star or delta. In my case, the engine is provided for 380/220V. I will use 220V. So I connect it into a triangle.

I connect "Phase" and "Zero" to any two points of the "triangle", and between the third point and the first or second one you need to connect a non-polar capacitor. In my case, you need 1uFx400V.

Unfortunately, I did not have this denomination. Nevertheless, you can demonstrate the operation of the engine: after applying single-phase voltage to two connection points, you need to “manually” scroll the engine shaft. Then he will pick it up.

The goal has been reached. The windings are connected correctly. (It remains only to buy a capacitor ...)

And now the video version of this article on my YouTube channel: