1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

Drum switch

Discussion in 'General Electronics Chat' started by Gregory, Nov 19, 2017.

  1. Gregory

    Gregory Member

    Joined:
    Nov 30, 2003
    Messages:
    367
    Likes:
    4
    Location:
    Australia
    I have a drum switch and a singel phase 240 v AC motor.
    I have the 2 wires I require to switch to obtain forward and reverse .
    Could you advise me how to wirer the drum switch to the motor to obtain forward and reverse.
    I have posted photoes of the motor and drum switch.
     

    Attached Files:

  2. dr pepper

    dr pepper Well-Known Member Most Helpful Member

    Joined:
    Oct 6, 2008
    Messages:
    4,763
    Likes:
    259
    Location:
    North west UK
    Firstly your switch doesnt look like a reversing dewhurst type switch, it looks like a 2 speed selector.
    Here in the Uk the colour code may well be different so what I say may not apply.
    The red & black or A & Az are usually the run winding, the other 2 wires going into the windings part of the motor are most likely the start winding, I see in the pic there is a centrifugal switch.
    Reversing the polarity of the start winding in respect to the run winding reverses a motor of this type, to do this you need a double pole change over switch, it may be possible to do that with the switch you have, you'd have to check it with a continuity tester to find out what contact arrangement it has.
    You should also meter out the windings of the motor before you try to run it.
     
  3. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

    Joined:
    Jun 21, 2006
    Messages:
    6,076
    Likes:
    524
    Location:
    Cleveland, OH, USA
    Since you are just reversing the start winding, the motor needs to be stopped before reversing it. Otherwise, it will continue to run in the original direction, perhaps with a little different sound.
     
  4. dave

    Dave New Member

    Joined:
    Jan 12, 1997
    Messages:
    -
    Likes:
    0


     
  5. Gregory

    Gregory Member

    Joined:
    Nov 30, 2003
    Messages:
    367
    Likes:
    4
    Location:
    Australia

    The blue and white wirer that are disconnected if they are swapped around then the motor will go from forward to reverse.
    I have connected the drum switch and I am able to go one direction and turn off.
    How do I wirer the drum switch now to revers the 2 wires .
    What information is require to enable you to help me with this problem.
     
  6. dr pepper

    dr pepper Well-Known Member Most Helpful Member

    Joined:
    Oct 6, 2008
    Messages:
    4,763
    Likes:
    259
    Location:
    North west UK
    I'm not sure you can as the switch looks as though its for 2 speed not reversing, the only way you could tell if it is possible is with a meter and some knowledge, you need to see if there is 2 sets of contacts that change over when you flip the switch.
    Its unlikely any problem would arise reversing direction whil the motor is running, the centrifugal switch disconnects the start winding while the motor is running, so long as you dont try and reverse while the motor is starting.
     
  7. Gregory

    Gregory Member

    Joined:
    Nov 30, 2003
    Messages:
    367
    Likes:
    4
    Location:
    Australia
    I have don a continuity test and documented to enable you to draw up a circuit for me.
     

    Attached Files:

  8. Les Jones

    Les Jones Well-Known Member

    Joined:
    May 15, 2015
    Messages:
    1,474
    Likes:
    191
    Location:
    Lancashire UK
    I am making the assumption that the switch has a centre off position where there is no continuity between any of the connections. If this is the case then this way of connecting the switch should work.
    201117.jpg

    This needs 6 wires between the switch and motor. If you can identify which terminals in the motor are the main winding, the start windin, the centrifugal switch and the start capacitor. (If fitted.) then only 4 wires would be required between the switch and the motor.

    Les.
     
  9. Gregory

    Gregory Member

    Joined:
    Nov 30, 2003
    Messages:
    367
    Likes:
    4
    Location:
    Australia
    You ar correct there is neutral position in the centre.
    Thank you for the drawing as I will wirer it up tomorrow.
     
  10. dr pepper

    dr pepper Well-Known Member Most Helpful Member

    Joined:
    Oct 6, 2008
    Messages:
    4,763
    Likes:
    259
    Location:
    North west UK
    I had prepared some more instructions on metering out the connections, but I see you already have answers.
    Super.
     
  11. Gregory

    Gregory Member

    Joined:
    Nov 30, 2003
    Messages:
    367
    Likes:
    4
    Location:
    Australia
    When the switch is in the neutral position both 10-9 and 11-12 are open
     
  12. Les Jones

    Les Jones Well-Known Member

    Joined:
    May 15, 2015
    Messages:
    1,474
    Likes:
    191
    Location:
    Lancashire UK
    As long as 9 to 10 and 11 to 12 are open in the off position it does not matter what state the other four contacts are in. I think you will be ablwe to use the metal strap removed from between 9 and 11 to connect 1 to 3. You can leave the strap between 5 and 7.

    Les.
     
  13. Gregory

    Gregory Member

    Joined:
    Nov 30, 2003
    Messages:
    367
    Likes:
    4
    Location:
    Australia
    Les Jones and other members thank you for your advice . I have wired up the motor and the motor workes very well.
    Have a merry Christmas and all the best for the new year
    Greg.
    This Forum is very helpful to me and others Well done
     

Share This Page