Question regarding a 12v DPDT switch

Discussion in 'General Electronics Chat' started by loydt, Mar 2, 2009.

  1. loydt

    Thread Starter New Member

    Mar 2, 2009
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    I have an RV with a power awning. There is a momentary switch inside on the wall for extend, retract. I decided to add a second switch for this in the outside storage area so I could put the awning up from outside as well. On the back of the existing switch, there are 4 pins and 4 wires. Orange is the hot wire, White is the ground, Red is the "extend" and Black is the "retract". The only dpdt switch I could find for the addition had 6 pins on it. I found a wiring diagram on here for wiring a dpdt switch for reversing motor polarity (which I assume is what they are doing here) and wired the new switch accordingly. I tried the new switch while the existing one was disconnected and it worked fine. I then reconnected the existing switch and tested it and it also worked. However, when I try the newly added switch WITH the existing one connected it pops the fuse. I don't know where the issue could be?
     
  2. wr8y

    Active Member

    Sep 16, 2008
    232
    1
    The problem is with the way you wired it! (Obvious, huh? :D )

    You are saying that red is one direction, black is the other - are you saying that the motor has three wires - red, black and a ground wire? That is, you put 12 positive volts on the wire of the direction you want to go and leave the other open?

    Or...

    does the motor just use red and black - reversing their polarity to change directions?

    This question is fundamental to how to wire this up. Once we get this established, we can proceed!
     
  3. loydt

    Thread Starter New Member

    Mar 2, 2009
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    Well, I used a test light to determine the wiring. While grounding the test light, the Red was hot while holding the switch in the "extend" position and the Black was hot while in the "retract" position. I friend of mine said it made no sense for the switch to have a ground wire unless they were using it as a "short" to keep the motor locked while going down the road?
     
  4. wr8y

    Active Member

    Sep 16, 2008
    232
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    The test light does not tell me what the other lead is doing. I have GOT to know if there are two separate windings (one for each direction) or one winding that you reverse polarity on to get the two directions.

    I THINK it's the second way (underlined above). In this case, the negative lead is there along with the positive lead to provide for reversing.

    I don't see how a ground will lock a motor. But then, RF and radio is my thing, not motors... no, just dont buy that one.

    I'll see if I can draw this out and post the drawing... but gotta run for about 2 hours ... got an economics paper to turn in online tonight!

    Mark
     
  5. wr8y

    Active Member

    Sep 16, 2008
    232
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    Hey, the switch you bought - does it have a center off position?

    That is, three positions? Or just two? If it just has two - WRONG SWITCH!!!!
     
  6. loydt

    Thread Starter New Member

    Mar 2, 2009
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    No, is a 3 position with center off. It's momentary also.
     
  7. wr8y

    Active Member

    Sep 16, 2008
    232
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    Ok, here's how I'd do it. Let's assume that the motor uses two wires and that we reverse polarity to reverse direction.

    As you look at the back of the switch, you will see six terminals:

    Term 1 Term 2

    Term 3 Term 4

    Term 5 Term 6

    Step 1:
    Connect the positive power lead to Term 1 and the negative power lead to Term 2

    Step 2:
    Connect the wires to the motor to Term 3 and Term 4.

    Step 3:
    Connect Term 1 to Term 6
    Connect Term 2 to Term 5

    That is it. Try moving the switch and seeing which way it moves. Label the switch accordingly.
     
  8. loydt

    Thread Starter New Member

    Mar 2, 2009
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    so there should be no issue with having two switches wired the same in that circuit?
     
  9. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    I think the reason that the actuator has a red/extend and black/retract wires is due to internal travel limit switches.

    Perhaps our OP (loydt) can tell us - does the awning, when controlled by the original switch, stop automatically when it is fully extended or fully retracted? Or do you have to release the switch to keep the motor from stalling?
     
  10. loydt

    Thread Starter New Member

    Mar 2, 2009
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    You have to release it when extending. It does seem to stop on its on when it reaches full retract.
     
  11. wr8y

    Active Member

    Sep 16, 2008
    232
    1
    I believe not. When either switch is in it's "off" position, it should be "open" in all directions. But the limit switch question is a good question... I was hoping someone other than ME would post.
     
    Last edited: Mar 3, 2009
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