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-   -   Rotary switch question (https://www.askmehelpdesk.com/showthread.php?t=829898)

  • Jan 14, 2017, 11:30 AM
    frmig
    2 Attachment(s)
    Rotary switch question
    This shouldn’t be that hard but I can’t figure it out.

    I have an old European combination woodworking machine with three separate and identical single phase 220v 3hp AC motors. The motor is selected with a drum switch with settings for motor #1 saw, motor #2 jointer/planer, motor #3 shaper, motor #2 reversed for mortiser.

    The selected motor is turned on with a manual rotary switch that is held until the motor gets to operating speed and then released (each motor starts around 32amps, goes down to 11.5amps on the start windings, and runs w/o load at 4amps after the starter switch is released.

    I wanted to also be able to reverse motor # 3 shaper. I was able to accomplish this by identifying the two start winding wires in the motor, and exchanging them. Now I simply want to install a reversing drum switch in the control panel to exchange these two wires to make the shaper run forward and backward.

    I purchased a suitable reversing switch, but the directions assume I want to use the switch to start the motor and reverse the motor at the same time. All I want to do is exchange the polarity of the two starter winding leads.

    I’m not good at the boolean logic required. The switch has 8 terminals, and three positions left, middle, right. On the right side 2 and 4 are common. When the switch is in the middle no circuit is complete except for continuity between 2 and 4. When the switch is turned to the left, 1 and 2, 1 and 4, 5 and 6, 7 and 8 are connected. When the switch is turned to the right, 2 and 3, 3 and 4, 5 and 6, 7 and 8 are connected.

    Anybody got an idea how to get the two starter winding wires from the motor to connect to the rotary switch so that two wires will leave the switch with the polarity changed one way and back? Jumpers needed?
  • Jan 17, 2017, 08:00 AM
    Stratmando
    Yes, it is wired like a Polarity Switch. Hard to describe with that switch. Can do if in my hands or schematic of switch and terminal numbers.

    It is commonly done with a Double Pole, Double Throw switch. Looking at the bottom of the switch six terminals, Connect top left to bottom right, and connect top right to bottom left. Should look like an "X". Then connect the 2 windings to the center, the remaining 2 wires to either end. This will Swap the 2 connections.

    With the Rotary switch, you need to have hot disconnect in off position.

    A 4 way switch has 4 terminals and swaps 2 wires.


    Only reverse direction when motor is stopped.

    Good Luck
  • Jan 19, 2017, 09:18 AM
    Stratmando
    This may help:
    https://www.google.com/search?q=pola...w=1366&bih=638

    This is only the reversing part of the switch
  • Feb 24, 2017, 07:49 AM
    Stratmando
    Sorry I didn't read bottom of you post, I had been looking for a diagram of terminals.

    Have to head out, will provide answer later, need to head out. Will have to decipher what you wrote to Each of the S.P.D.T. actions. Take care
  • Feb 25, 2017, 09:16 AM
    Stratmando
    Does that switch have positions to allow starting.
    They may make that switch. Most I do are 3 positions, forward, off, and reverse. Sounds like you need 2 more positions. Have tried to find diagram of terminal connections. This Company makes it Very Very difficult, see if you can make sense out of the connections. You say left position is 1 and 2 and 1 and 4. is that the same as 1, 2 and 4 connected?:

    http://www.lovatoelectric.com/Handle...switches_01_14
     
     
    http://www.koncar-nsp.hr/en/products...ches/Series_GN
    Let me know what you find. May be there, I can't find, Thanks
    Good Luck

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