Re-winding of an old Brook Motors Ltd.

Discussion in 'General Electronics Chat' started by Vakse Viggo, Jun 20, 2017.

  1. MaxHeadRoom

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    Jul 18, 2013
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    Motor winding copper has much better enamel now with modern materials, it usually takes quite a bit of effort to get it off even when you need to intentionally.
    Max.
     
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  2. KeepItSimpleStupid

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    Mar 4, 2014
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    Very nicely done. If you have time, maybe a brief synopsis and the difficulties you encountered summarized.
     
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  3. shortbus

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    I agree, there is so little information out there on how it is done even a small step by step would probably give others the confidence to try it.
     
  4. Vakse Viggo

    Thread Starter Member

    Jun 15, 2017
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    Absolutely...I will make small guide with everything 'I' encountered.
     
  5. shortbus

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    What would be very interesting to me is how you came up with the "steps" on the winding form. I know that's how they are made and look like, but how you determined the sizes. And again this was a very professional looking job. Hard to believe it's your first one!
     
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  6. Vakse Viggo

    Thread Starter Member

    Jun 15, 2017
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    I was quite surprised myself to be honest. :)

    The size of the windings, I just copied from the old ones...so that was nice and easy. About the form...I have looked at so many factory winding videos on youtube, and saw how they did it. Then I just scaled it down a bit, and made one end of the form loose, so the winding could be removed from the form.

    Just want to share how they connected it, back in the days...no crimp, solder, shrink or earth on the mains! I doubt that this was done by Brook Motors in England. I am sure it was done in Copenhagen, where they also removed the capacitor housing on top, because it would get in the way of the large cover.

    I need to redo the shrink tubing on some of the 1,5 mm2 silicone wire, because I ran out. The spacer for the last bearing will arrive tomorrow, and then it's assembly time.

    DSC_0081.JPG DSC_0082.JPG DSC_0801.JPG
     
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  7. Vakse Viggo

    Thread Starter Member

    Jun 15, 2017
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    I have now put everything together and it does run, and in right direction, but only for about 10 seconds...then the automatic breaker shuts down (fuse box). It can handle 10 amps.

    It also gets very varm, very fast.

    First I thought it was the start windings that did not turn off, but thats not the case.

    I meassured both start and run windings, and they both have the same steady resistance....Run 2 ohm. Start 16 ohm.

    Could it be that the Speed Switch and the Start Capacitor have to be changed around?

    Here is the diagram again...

    Vikling forbindelser - 2i.jpg
     
  8. Vakse Viggo

    Thread Starter Member

    Jun 15, 2017
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    Tomorrow I will try to wire it up to my 16 amp connection and use some ground on the motor, and see if that makes a difference. On the spec. plate it says Start 20.0 and Full Load 4.1 amp.

    That could explain the heat it generates...?

    DSC_0139.JPG
     
  9. cmartinez

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    Does it run at the rated rpm's when you start it?
     
  10. Vakse Viggo

    Thread Starter Member

    Jun 15, 2017
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    I dont own a RPM counter, but it starts really easy, comes up to speed and the speed switch goes off. After about 10 seconds, the breaker goes off.
    I did order a tachometer from China, but it wont arrive anytime soon.
     
  11. Vakse Viggo

    Thread Starter Member

    Jun 15, 2017
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    Okay...so after I connected it to the 16 amp fuse, it did not trip the breaker. BUT....it got so hot, so fast, that a little smoke came out...hardly anything, but still.
    The windings still meassure the same resistance, so looks like I just got away with the scare. :eek:

    Now I got a 230 volt micro switch installed, instead of the speed switch. My suspicion is still on the old speed switch. Lets see how it works when it's done manually....
     
  12. Vakse Viggo

    Thread Starter Member

    Jun 15, 2017
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    Okay...that did not work either.

    I am going to try and switch the Positive and Neutral around on the run winding. What happens if the Start and Run windings, have a different Fase and Neutral?
    Is it not the Start windings that decides in what direction the Rotor have to turn?
     
  13. GopherT

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    Nov 23, 2012
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    Are you using the same old original capacitor? Do you have a photo of the new one?
     
  14. Vakse Viggo

    Thread Starter Member

    Jun 15, 2017
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    The new one at the left...sorry for the angle. But it is not the Start windings thats the problem now, its the Run windings that are running super hot, very fast.

    I am just letting the motor cool down, and see if switching Fase and Neutral on the Run side will do any difference?


    DSC_0814.JPG
     
  15. Vakse Viggo

    Thread Starter Member

    Jun 15, 2017
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    I did an inspection of the windings, and could see some magnet wire gave the insulation paper some color. This is how the two run poles look like, one at Fase and one at Neutral...the other two seem fine.

    On the other picture is how the run windings looked like when I took them out, and that matches this drawing of a similar motor. But thats not the same as it looks like now. By me the Beginning and End, is switched around...could that be the problem?

    It is possible to reverse this, if that is the case.

    ælmælmæ.jpg

    DSC_0122.JPG

    4 pole connection.jpg
     
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  16. cmartinez

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    Yes, there's a strong possibility that that's indeed the problem ... it won't hurt (any worse) to try
     
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  17. MaxHeadRoom

    Expert

    Jul 18, 2013
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    If you have a coil winding reverse connected then it will cause that symptom.
    Max.
     
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  18. Vakse Viggo

    Thread Starter Member

    Jun 15, 2017
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    Thank you....it's nice to know before I take everything apart.

    It didn't take long at all, to expose the four run connections....but I do hope that this will do the trick. All four poles meassured excatly 1.1 ohm's...so that must be a good sign. :)
     
  19. Vakse Viggo

    Thread Starter Member

    Jun 15, 2017
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    Okay, so now the Run windings look like the ones from the drawing. Before it measured 2.0, but now it says 3.8?

    I am very interested to know why it's not the same as before...my logic says it have to be. :)
     
  20. cmartinez

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    That's an interesting observation ... to measure resistance, a MM applies a small voltage to the device being measured, and by measuring the current going through it, it then calculates the resistance. To be honest, I'm not sure if it's the other way around. That is, that it applies a small current, and then measures the resulting voltage. But the principle is the same.

    Anyway, an MM applies this signal in a periodic manner, and not continuously. That means that it works at a certain frequency, and it's trying to measure a resistive (as opposed to inductive) load. If the resulting inductance of your coil arrangement has changed due to the rewiring that you've just done, then maybe that's why the measurement is not the same.
     
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