Track feeder wires for dummies

Discussion in 'FAQs' started by ExtremePCs, Apr 2, 2006.

  1. EngineerKyle

    EngineerKyle Member

    Well, I don't have the brain for this, but, generally, is it possible to NOT have a reversing section but STILL get a short?

  2. EngineerKyle

    EngineerKyle Member

    Jayson and Ron,

    I'm getting more curious and love solving problems.... I don't think the layout in your pic has a reversing section or would ever cause a short. With a careful eye, I copied your schematic, omitting the "dead end" spurs, with a single red pencil line. Then I started a second "inside" line in blue. As I paralleled the first line, sometimes the blue line seemed to become the outside rail, but this is because of the nature of figure eights, as they obviously double back on themselves. After correctly following the routes and turnouts with the second line, I ended up back where I started. No shorts, no reversing section. I'm sure of this.

    Now you say this is a physical layout and it always shorts in the same spot. Is the physical layout exactly the same as the picture you've included in this thread? Do you agree that there are only six turnouts that control the main routes? Maybe you have a bad turnout or crossover somewhere? Anyway, I'm confident that the layout plan you've shared is a ONE WAY only.

    Good luck and please keep us posted.

  3. EngineerKyle

    EngineerKyle Member

    announce1 feeder wire crossed?
  4. Gary Pfeil

    Gary Pfeil Active Member

    I haven't read the replies to this thread, so maybe I'm missing something, but looking at the last drawing posted, I see two reverse blocks. Basically the layout is a double tracked circle, in a figure 8 configuration. The two turnouts on the extreme right hand side, one on each track, are the leads to the two reverse blocks, which extend to the turnouts at the other end.
  5. ExtremePCs

    ExtremePCs Member

    Yes, my layout is exactly as pictured. One thing that does not show up in the picture though are the bridges. Sorry... I should have mentioned this sooner for those of you who are not familiar with this particular track plan. The green areas indicate the bridges (i.e. they do not touch the track below)

    View attachment 26251

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  6. EngineerKyle

    EngineerKyle Member

    OK, I thought the bridges were crossovers.... doesn't matter for the problem at hand. Maybe I'm missing something, but as I said, I see no reversing section. I really respect Gary, but I don't see it. Did you try the experiment with a marked box car yet? Love to know what that reveals, my guess is you will not be able to get it to reverse, no matter what route you try. You are shorting out when the loco crosses a certain turnout? what happens when you push the loco along a little ways farther down the route? Is there a certain point where it starts to run again? If it does run further down the line, then it would seem to me that if you have a reversing loop polarity problem, The loco would short out again at a SECOND point, the other "end" of the reversing section. I'm just thinking out loud now, hoping that something might click for you that you haven't tryed yet.

    By the way, I made a big copy of the layout on my blackboard with colored chalk. Still looks like it should work with no polarity issues.

    EK :rolleyes:
  7. pgandw

    pgandw Active Member

    Here are some likely causes for the short.

    - Wiring error. Are you using common rail and just insulating one rail for each block? Or did you insulate both rails? If the short circuit occurs without any train on the track, then it is likely you have crossed your feeders.

    - Another possibility for a short in the area without a train is an internal short at the turnout. Yoou would have to remove the turnout and see if the short is still present.

    - Another gotcha that happens more often than you would think (at least to me) is something metal across the track. My Kadee couple height gauge is my downfall. A track nail, spike, or sliver of metal is all it takes, especially in the turnout. Go through the track in that area with a drop light and magnifying glass and/or vacuum the track.

    - If the short happens only when a train is going through the affected area, chances are very good a wheel set is shorting across the frog rails of an Atlas turnout (Peco Insulfrog sometimes have this problem, too.). Remove/add cars and change locomotives to see if you can identify the offending culprit(s) and exactly where the short takes place. Check the wheel gauge of the offending locos/cars very carefully with an NMRA gauge. Also check the turnout carefully with the NMRA gauge. Adjust anything that is not within spec. Last check is to put finger nail polish where the closure rails of the frog come close to each other, and where the rails come together at the frog point. Sometimes the plastic wears there and a metal wheel (especially out of gauge) bridges the gap.

    Hope this helps.
  8. MasonJar

    MasonJar It's not rocket surgery

    Fred's comment about the metal wheels reminded me of this story...

    A friend's operating session was completely shut down by a short caused when metal wheels in a poorly sprung truck touched the underside of the car, which was a cast metal part. Took about an hour to find the cause... The kicker in the story was that the car had been "bad-ordered" before the session, but the owner of the layout put the car back on the rails...! :rolleyes:

    He has not heard the end of it yet! :D

  9. farmer ron

    farmer ron Member

    The next step is one of process of elimination..take everything off the tracks and like it has been mentioned before, ensure EVERYTHING is off the track. turn power there a short..with still nothing on the track throw each switch separately, is there a short at any one of these spots if so it is either the switch or wired improperly..if no problem continue by putting on your locomotive. I noticed mentioned the area of problem is outlined in blue, there is a switch with bridge over top. Run your loco slowly on the layout and into the problem area..when you have the short..STOP..SHUT POWER OFF..DO NOT MOVE LOCO !!!!. With lots of light take a good look at where each one of the wheels are in conjunction to what they are touching and the area around the loco, this will isolate your problem location. By the way, does each loco do this or just one have this problem? See if you can spot the problem, if not mark beside each wheel location beside it with a small pin pushed into the roadbed beside the track, remove the loco, turn the power back on and check you powerin that spot and area with a volt tester, you will find out that you may have inadvertenly got your feeder wires mixed or your wheels touch another track and short out..Ron.
  10. Gary Pfeil

    Gary Pfeil Active Member

    Doh. I assumed the double tracks were wired the same polarity, in which case there would be two reversing blocks. If they are wired opposite each other there are no reverse blocks, sorry. So if you are having a short at the turnout circled, it is either a turnout or wiring problem. What turnouts are being used?
  11. ExtremePCs

    ExtremePCs Member

    I have not actually hooked up a power pack yet. I "see" the short when I join two section together and the wire colors are reversed. I verified that there is a short by usng a short detector, built from a 9V battery and an old computer speaker. The speaker goes off when I connect the rails. I verified the short detector is working correctly by hooking it up to a single section and the speaker remains silent until I cross the rails with a screwdriver.

    Someone sent me this picture (hard to see the + and - signs in the small format) showing how they wired their layout. He said he has no shorts, no insulators, no problems. I'm going to play aroud with it tonight, using colored pins first BEFORE I solder. :)

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  12. Gary Pfeil

    Gary Pfeil Active Member

    My eyes don't allow me to see the polarities marked. However, here is my suggestion, based on an assumption that you are talking dc and want to have blocks to be able to hold trains on, and are using Atlas turnouts. The two parallel tracks forming the double track figure 8 should have opposing rails connected to one ploarity, ie, the two rails of each track closest together ought to be connected to the same polarity, with the outermost rails connected to the other polarity. For now, gap both rails of what I had previously assumed to be reverse blocks at each end and disconnect all feeders. See if you still have a short. Let us know what happens and we'll go from there.
  13. 60103

    60103 Pooh Bah

    In post 19, the red line that snakes down through the middle should be on the other side of the track. As someone said, the double tracks should be wired opposite to each other -- opposite direction running.
    Try the exercise again, but start one line and continue it around.
  14. EngineerKyle

    EngineerKyle Member

    My assumption is that you are going DCC, and if you are, You should consider removing all insulators and isolate nothing. It will REALLY simplify things in my mind.


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