transformers

Discussion in 'General Electronics Chat' started by doyler, May 2, 2013.

  1. doyler

    Thread Starter New Member

    May 2, 2013
    1
    0
    help please i bought a three phase ban saw, and a single phase to three phase transformer. there are 4 wires coming out of the transformer ,blue, black brown and green and yellow earth. but there are 5 wires to be conected on the band saw, green and yellow earth , red ,blue.black,yellow. Does any body know how i should wire this? thanks
     
  2. wmodavis

    Well-Known Member

    Oct 23, 2010
    737
    150
    Not sure what to assume about your claim of having bought a "single phase to three phase transformer" because there is no such thing as a transformer that will accept single phase input and produce a 3-phase output. There ARE other ways this can be accomplished but not a transformer.

    So you need to clarify what it is that you actually have so we can get past the guessing stage based only on your meger and inaccurate description.

    Pictures and/or manufacturers data could help.

    Without better information it is a real guessing game not too likely to be productive unless someone has a much clearer crystal ball than myself.
     
  3. Brownout

    Well-Known Member

    Jan 10, 2012
    2,375
    998
    There seems to be little reason to guess what he has, since it's clearly not what he thinks it is. He'll have to find some other way of running his say, or else trade it for one he can run on his home power.
     
  4. Brownout

    Well-Known Member

    Jan 10, 2012
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    998
  5. shortbus

    AAC Fanatic!

    Sep 30, 2009
    4,013
    1,531
    First one of these I saw, the guy used a rope wrapped around the pulley of the 3PH motor to get it spinning, like starting a lawn mower. Adding caps to the three phase motor also will get a better balanced out put.
     
  6. Brownout

    Well-Known Member

    Jan 10, 2012
    2,375
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    I saw several videos before where someone started a large 3-phase motor with a capacitor and momentary switch, then used the motor running on 1 phase to power his 3-phase motor. I tried to find a video showing that, but couldn't.
     
  7. WBahn

    Moderator

    Mar 31, 2012
    17,743
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    Interesting homework!

    @OP: In the future, something like this should be posted in the General Electronics Discussion forum. It will probably get more attention and responses.
     
  8. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    This is a bit unusual. Homework refers to school work, not to work you do at home. Since this did not belong in the Homework forum I have moved it to a more appropriate forum.
     
  9. rays

    New Member

    Mar 11, 2009
    4
    0
    in regard to the wires coming from the band saw
    do they come to the junction box on the motor or are they just at the end of a cut cord?
    green earth
    black newtral prob not used unless going to a 240v start run relay located in the stop go box
    the remainder going to each of the phases to the motor via possibly a start relay located in the stop go box
    you will have to generate the 3 phase from something more than a transformer!
    perhaps you have single to 3 phase converter and are calling it a transformer
    assuming this
    the three wires (not counting the earth )would be one to each phase
    of the motor
    when they are connected (presuming they are in fact 3 phase)the motor will run either forward or backwards to change its direction of rotation change any 2 of the 3 phase wires
    so befor starting!!!!!!!!:mad: please remove band blade as if run backwards it can run off the pulleys!!!!!!!!!
    now the black newtral wire
    if it is needed to operate the relay
    it will be conected to the coil that pulls the contactors closed and probably operates at 240v (assuming the 3 phase is 415v)
    so if you can provide an active and a newtral from before your converter
    this could be used to operate the coil in the stop go box BUT only play with this sort of voltage if you can get it checked by a licenced sparky as it can KILL you:mad::mad::mad:
     
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