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I've just pulled apart an old russian washing machine to extract a couple of motors to use as in windmill generators I'm making. I don't know much about motors, so I'm kinda new to this but want to learn about it.

One motor has 4 wires coming out of it. 1 wire is copper, the other 3 I think are aluminium. The copper wire has red insulation, there's another red one, a black and a blue. There is also a 5th wire connected to the body which I'd guess is ground/earth.

I've read a few posts around the place like testing with a multimeter the resistance between the wires to find pairs.

The resistance between:

  • Red(copper) & red(aluminium) wires: 19.2ohms
  • Red(copper) & black: 1.4megaohms
  • Red(copper) & blue: 1.3megaohms
  • Red(aluminium) & black: .9megaohms
  • Black and blue: 51.2ohms
  • Red(aluminum) and blue: 1megaohms

So from what I've learned, whatever pair has the least resistance is connected to the Armature and therefore, the other 2 are for the field. In my case then, red and red are armature (brush?), black and blue are field

What I'm curious to know is, how would I connect these wires for using it as a generator? I saw a video of a guy connecting the 4 wires into 2 to 'induce some voltage' as he says.

If I connect mine the same (2 red wires together, and black and blue together) then connect it to a multimeter to test volts and give the motor a spin, I can see it's creating a AC voltage, but not much (.02v). I'm not using a drill. If I switch it to testing DC voltage, nothing changes when I turn the motor. So I'm assuming it is an AC motor but I really don't know. How can I be sure?

BTW, these are the details from what I've gathered reading the russian 180v, 1.5a, and I think 1350RPM. Here's a photo(s) if you happen to be able to read this:

enter image description here enter image description here

Any tips for this would be greatly appreciated! Thanks

willdanceforfun
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1 Answers1

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Washing machine motor (especially an old one) is most likely to be an asynchronous motor - they can't work as generator. The minimal voltage you see comes from residual magnetization of the rotor acquired over the years. A brand-new specimen wouldn't yield even that.

You should have noted how the motor was connected before you took it apart. One pair is probably the main phase and the other the startup phase, powered via a capacitor to achieve a phase shift. There is no winding for the rotor. Capacitor start induction motor on Wikipedia

About the photos you posted: I can see the word "kondensator" which means "capacitor", and "6mkF 600V" which seems to be "6μF, 600V". That most likely is the spec of the capacitor required for operation. I think it reads 50Hz, 180W, power factor 0.9 (cos fi), 220V, 1.5A.

/edit: Ah, I forgot about one thing. Washing machine motors usually are bit more complicated because they have twin windings to be ran in reverse and often have yet another, "high speed" winding for spinning. But that's all in the stator, the rotor is just a hunk of metal just like any other induction motor. If you want to learn more about your motor, google yields some schematics if you ask about this model: https://www.google.ru/#q=%D0%B0%D0%B2%D0%B5+071+4%D1%81

(A tip for future research on russian and soviet parts: open google.ru, it has Cyrillic on-screen keyboard so you can actually type the model you have)

Agent_L
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  • Thanks for that. I actually cut the wires instead of disconnecting so I can still see where they were joined. I'll update the question with a photo of that if it helps. – willdanceforfun Dec 10 '15 at 08:43
  • Where you said there is no winding for the rotor. What does that mean? Is that why it can't be used as a generator? I'm just looking at a video where an induction motor is converted to be used as a generator by adding magnets into the armature. Does that make it possible? See https://www.youtube.com/watch?v=jb-C4vYJxWE – willdanceforfun Dec 10 '15 at 08:53
  • @willdanceforfun I edited my answer a bit. Thanks, but I don't think more photos can really help - unless you think it's not really an async motor (eg there is no capacitor) and photos can disprove my hypothesis : ) – Agent_L Dec 10 '15 at 09:00
  • @willdanceforfun Yes, the induction (async) motor can't generate because the rotor has no magnetic field on it's own, it only reacts to stator field. It can be converted to a synchronous motor by replacing the rotor or by adding magnets to it. But it basically means you're building half of the motor from scratch. You'll likely get performance comparable to a toy motor (as the author of the video). To do it right, it would be many times more expensive than just getting a proper synchronous motor. – Agent_L Dec 10 '15 at 09:01
  • What you CAN do out of this motor is a lawn mower : ) – Agent_L Dec 10 '15 at 09:04
  • Hey thanks for your time and explaining anyways. I'll pull out the other motor now and see if it is the same. You really think it could be used for a lawn mower? How come though in the video link I posted in the question that guy has a similar motor (4 wires) and when he turns the drill it looks like he's getting 15v? My motor looks really similar to his. – willdanceforfun Dec 10 '15 at 09:07
  • @willdanceforfun Yeah, by adding magnets to the rotor he converted it into synchronous motor. But look at those big, expensive neodymium magnets he used - most likely one could buy a decent generator just for the price of those magnets! Plus, I don't like how he just hammered them in - they will be subject to heat, vibrations and strong centrifugal force. If one ever come bit lose - the motor will be destructively halted (explosion style!). Putting his converted generator into serious work is just an accident waiting to happen. – Agent_L Dec 10 '15 at 09:20
  • Yeah I don't want to have any exploding motors! And the point of using an old motor like this is so I can save money and not shell out for extra magnets etc. But the video I was asking about was the one in my question, not my comments (this one https://www.youtube.com/watch?v=M0_QG72ae2U). He doesn't appear to have modified his motor at all. Are there motors like this with 4 wires which aren't induction / asynchronous motors? BTW that is brilliant about the google.ru tip! I was wondering how I could search the russian part! Thanks! – willdanceforfun Dec 10 '15 at 09:59
  • @willdanceforfun ah, sorry, I missed that. Well, he's talking about brushes, so it must be an "universal motor". Those are usually found in smaller applications like vacuum cleaners, blenders, drills. Big or long-running appliances tend to have async motors, small ones which are turned on occasionally often do with universal motors that you want. Synchronous motors that work best as generators are pretty much impossible to be found in any popular devices, except for very small ones in turntables, magnetic tape players, floppy drives (where precise speed is the most important factor). – Agent_L Dec 10 '15 at 10:13
  • I'm getting a bit of an understanding now, thanks. This will help me when I'm sorting through old machines left behind in this house we bought to find something to be used for a generator. Actually, there is an old vacuum cleaner there as well, and now you mention it, a turntable and tape player also! I wouldn't have thought to look in them. Thanks again man! I'll these async motors aside in the meantime, maybe down the track I'll make a battery powered lawn mower. I just did some math though to workout horsepower of this one. (180v x 1.5a x 60%) / 746 = .26hp. Is that enough for mowing? :D – willdanceforfun Dec 10 '15 at 11:17
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    You can use an induction motor as a generator IF you already have electricity applied to it (rotor excitation) and IF you can control the speed to just above the synchronous speed, however, that may be very difficult or impossible in a windmill application. – Joel Keene Dec 10 '15 at 20:11
  • @JoelKeene Theoretically yes, but I've never heard about single phase induction generator. – Agent_L Dec 11 '15 at 09:59