Help with an old motor

Discussion in 'General Electronics Chat' started by Garurumon, Jul 26, 2013.

  1. Garurumon

    Thread Starter Member

    Mar 17, 2013
    99
    1
    I found an old motor from some kind of water pump, but some of it's wires are missing.

    There are two (AC input?) wires in one base of cylindrical start capacitor (says 250V 2A 0.07uF), and two wires on the other side of the cylinder, on the other base, and they go to one stator coil each (there are 2 stator coils).

    I counted 8 poles on the rotor, and it's induct is wound, not permanent magnet.

    Now, the problem, brushes are completely disconnected, and I have no idea where they go. I can't see to find any torn wires sticking out form the stator coils. Where do I connect those?

    Thanks in advance :)
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,549
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    Start capacitor usually implies a split phase (AC) induction motor? But if it has a wound stator & rotor and the rotor has a commutator, it could be a Universal motor, (armature and stator in series), if shunt connected then it would be DC.
    Is there any kind of label on the motor?
    Are you sure it was previously AC fed?
    If it is a Universal motor, careful about running it off load, they operate in a runaway condition and require a load to govern the maximum rpm.
    Max.
     
  3. PackratKing

    Well-Known Member

    Jul 13, 2008
    850
    215
    Max is right...
    Pictures would be a good idea... not too many clairvoyants on these forums...:D
     
  4. Garurumon

    Thread Starter Member

    Mar 17, 2013
    99
    1
    Well it mentions frequency rating on the capacitor, so i guess so... I'll draw you the only inscription:
     
  5. PackratKing

    Well-Known Member

    Jul 13, 2008
    850
    215
    you really need to post some pictures of this... your thumbnail lists far too small of a capacitor value for any motor I ever worked with...
     
  6. Garurumon

    Thread Starter Member

    Mar 17, 2013
    99
    1
    It's kinda disassembled right now cause i was removing the parts I will not need for my project (propellers), but here you go:

    http://i210.photobucket.com/albums/bb204/n00blord1/motorce_zps5e000404.jpg

    I hope it's visible... rotor is in the casing on the left, at the bottom is capacitor, and on the right is stator.

    EDIT:

    I made a mistake on the picture, it's 0,07u!!!

    My electronic English just isn't good enough to google it, sorry :/
     
  7. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Definitely looks like a Universal motor, especially AC fed.
    The cap (L/C R/C) is for noise/arc suppression.
    Max.
     
  8. Garurumon

    Thread Starter Member

    Mar 17, 2013
    99
    1
    And the brushes, where should they be connected?
     
  9. MaxHeadRoom

    Expert

    Jul 18, 2013
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    On a Universal motor, the armature/brushes and the field are connected in series with the AC source, to reverse the required direction you will need to swap one pair with respect to the other, IOW swap the field wires over.
    The suppressor would be connected in the AC source L & N.
    Looks like a vacuum cleaner motor?
    Max.
     
  10. MaxHeadRoom

    Expert

    Jul 18, 2013
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    It looks like the conductors have been removed from the brushes??
    In some cases the wires are attached to spring clips that go over the brass portion of the brush holder.
    Max.
     
  11. Garurumon

    Thread Starter Member

    Mar 17, 2013
    99
    1
    Pffff, I don't really know much about motors.

    Could you please explain me what wire goes where? :)

    What should I connect to the pair of green wires, and what should I connect to brushes?

    I don't think it's a vacuum cleaner motor, it has aluminum water pumps on it's "working end" :)
     
  12. Garurumon

    Thread Starter Member

    Mar 17, 2013
    99
    1
    Yeah, that's what I'm trying to tell :D That's why I have no idea what goes there :D
     
  13. MaxHeadRoom

    Expert

    Jul 18, 2013
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    The AC supply would be fed into the spade terminal end of the suppressor.
    From the pair on the other end, one would go to a motor brush, then from the other brush to a field conductor, the other field conductor would be the return to the other suppressor terminal.
    Look up series connected.
    Max.
     
  14. Garurumon

    Thread Starter Member

    Mar 17, 2013
    99
    1
    By armature, do you mean laminated steel plates on the rotor, or...?
     
  15. Garurumon

    Thread Starter Member

    Mar 17, 2013
    99
    1
    And field conductor, is that stator windings?
     
  16. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Armature - rotating part, field - stationary part.
    Max.
     
  17. Garurumon

    Thread Starter Member

    Mar 17, 2013
    99
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    Get it, thank you very much for your help :)!
     
  18. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Keep in mind that without a load, ~20krpm is possible?
    Max.
     
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