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  • Electric motor question

    Please excuse my meagre electrical knowledge - it's all still magic smoke to me.

    I happened across an old Chinese aircon unit (well, swamp cooler) and dismembered it - as one does - to see if there were any useful bits. There was quite a sturdy looking motor which drove a squirrel-cage fan which pulled air through a sort of wet roller towel contraption. The motor has six wires coming out of it (seven, if you count the ground wire attached to the case) which bamboozled me as I am only familiar with two. Two of them go to a thing which I think is a capacitor.

    I found a rudimentary wiring diagram inside the case which said, of the remaining four, white was high, yellow was medium and blue was low, from which I cleverly deduced that the remaining black one was probably neutral.

    I have tried connecting blue & black to the power, then yellow, then white but the motor doesn't seem to go any different speed whichever live wire I use. Is it possible that I need to connect more than one wire at a time to live to make it go faster (maybe all three for top speed)? Thought I'd ask first as I don't want to cause sparks or make the magic smoke escape.

    Incidentally, the plate says 230V - 05 AMP, what would the power be?

    John C

  • #2
    Is that "5" or 0.5? Assuming it's 0.5, the motor is 0.5x230 = 115 watts, which is about 0.15 hp. That sounds about right to drive a blower.
    ----------
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    Don't believe everything you know. -- Bumper sticker
    Everybody is ignorant, only on different subjects. -- Will Rogers
    There are lots of people who mistake their imagination for their memory. - Josh Billings
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    • #3
      If the motor is 230v, the black wire goes to the other line lead not common. If you connect it to common, you're only feeding the motor 120v. No wonder it didn't do anything.

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      • #4
        This is in London, England. I'm not sure their electricity follows the same rules ours does.
        ----------
        Try to make a living, not a killing. -- Utah Phillips
        Don't believe everything you know. -- Bumper sticker
        Everybody is ignorant, only on different subjects. -- Will Rogers
        There are lots of people who mistake their imagination for their memory. - Josh Billings
        Law of Logical Argument - Anything is possible if you don't know what you are talking about.
        Don't own anything you have to feed or paint. - Hood River Blackie

        Comment


        • #5
          Are you trying it with or without a load on the motor? A lot of fan motors are variable power motors (A three speed might be something like 1/12hp, 1/6 and 1/4) and will run the same speed unloaded. Once you put a load (a fan) the motor will run slower.

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          • #6
            Originally posted by SGW
            This is in London, England. I'm not sure their electricity follows the same rules ours does.
            Ops, I missed that.

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            • #7
              Electric motor question

              Thanks, guys.

              Macona -- no, I haven't tried it under load.

              When I said I tried the different colour wires perhaps I wasn't clear. I did blue & black, yellow & black, then white & black. The motor seemed to run the same speed each time. I was wondering whether the switching on the machine might combine more than one wire at a time along with black, or is that unlikely?

              Incidentally, the plate says "05 A" without a decimal point so I'm guessing five amps. The thing weighs about 5 or 6 pounds.

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              • #8
                Originally posted by john clements
                I was wondering whether the switching on the machine might combine more than one wire at a time along with black, or is that unlikely?

                Incidentally, the plate says "05 A" without a decimal point so I'm guessing five amps. The thing weighs about 5 or 6 pounds.
                I have never seen any motor setup where they switch more then one coil on at a time. This does not mean they don't exist.. just that I have not seen them so its highly unlikey. Its much more likey macona is correct, It varys the HP of the motor, Not the peak unloaded RPM's. Ie, load will make it spin slower at the lower settings as it loses RPM's to maintain its HP settings (Less rpm's = less HP for same torque load)

                Peak unloaded RPM's is more a function of motor design and type, Not power.

                Even at 5lbs I would suspect 0.5A over 5A, 115W is just right for a small blower... 1150W (5A at 240v) is enough for.. uhhh.. this: http://wpsmedia.latimes.com/image/ba...-872-large.jpg

                Even a furness fan is only like 300~600W. Infact likey the only reason your fan is as high as 115W is because its so damn inefficent. (small electric motors are typicaly very poor efficency)
                Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

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