Feeder Wire

Discussion in 'N / Z Scale Model Trains' started by SeriousSam, Sep 21, 2006.

  1. SeriousSam

    SeriousSam Member

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    howdy all. I am wondering how Feeder Wire is hooked. I am planning a 32 foot section of single track and I would like to add feeder wire every four or five feet. I will be using just regular DC. Where do I hook up all the extra wires? What kind of wires should I use? Any info would be appreciated. Thanx
  2. pgandw

    pgandw Active Member

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    Serious Sam

    I urge you to consider creating electrically isolated blocks of track so that you can run 2 trains or run 1 and park 1. See the thread in the Technical section on setting up blocks.

    At each power pack, mount 2 terminal blocks (screw barrier terminal blocks are easy to use). Connect 1 terminal on the power pack to 1 terminal block (using 18 gauge wire), and connect the other power pack terminal to the other terminal block. Hook up a jumper (18 gauge is nice here too or Radio Shack has metal bridge strips that do the same thing) to all the screws or lugs on the same side of the terminal block as your power pack connection. The terminal blocks serve as the distribution point for your track power.

    For each block, you need a block toggle switch (DPDT center off, at least 12V 1 amp, can be a slide switch but toggles look nicer and are easier to mount). Run a wire (18 gauge) from one terminal block of power pack A to the SAME corner of all the block toggles. Run wires from the other power pack A terminal block to the other corner on the SAME end of the block toggles.

    Now run wires from the power pack B terminal blocks to the other set of end terminals on the block toggles, just like you did for power pack A. If you don't have a 2nd power pack yet, you can omit this step until you do.

    From each block toggle run an 18 gauge wire from the left center terminal to a terminal block near the block under the layout. Do the same to another terminal block for the right center terminal of the block toggle. These terminal blocks become the distribution points for the track feeders within a block. Again, a jumper is needed to connect all the lugs or screws of the terminal block to the block wires you just ran.

    It is important to stay consistent here, wiring the same center terminal to the same rail throughout the layout! On a layout that supposedly runs east and west, one rail, the inner one on a loop, is usually designated the North or N rail. The outer rail of a loop becomes the S rail. So the terminal blocks out near the track blocks should be labeled N or S. And one side of the block toggles becomes the N side and the other the S side. And finally, the same at the power packs - one terminal block is labeled S and one is labeled N. Keep all the S wires separate from the N wires, and only going to their respective S and N terminal blocks.

    Finally feeder wires - 24 gauge is good, although some use as heavy as 20 gauge - are soldered to the rail or rail joiner, and the other end connected to the terminal block for the block the feeder is located in. Again, keeping the S and N rail wiring separate and consistent is important!

    That's it. It's easier to do than to read or write about.

    Hope this helps
  3. DavidB-AU

    DavidB-AU Member

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    I don't see why you would block up a section of single track. Train control goes to great lengths to prevent more than one train at a time on single track!

    For plain track I solder all rail joints and add a feed wire to every second joint. I find it is convenient to solder the feed wire to the under side of metal rail joiners where they can't be seen. Telephone drop wire is ideal for this as it can be pulled apart into single wires and will readily hold a right angle while you solder it in place. Ideally this can be done before the track is laid, i.e. if you're using flex track (or even building your own) then join two lengths together and add the feed wires to the middle. When you work out exactly where each set of feed wires will go, you can drill holes directly under where each rail will go. Once you pull the feed wires through, if you've judged everything well then it can be very hard to see the feed wires even before you ballast the track.

    I also find light duty figure 8 speaker cable is ideal for the bus wire under the layout and sufficient for most applications. If you plan to run very power hungry loco combinations (e.g. quad Bachmann Spectrum) then you might think about medium duty speaker cable. You can splice the bus wire and solder on the feed wires, but personally I try to avoid soldering where possible and terminal blocks at the site of each set of feed wires is helpful.

    Here's an example from a recently constructed Austrak module. You can see where the feed wires are (at the rail joints) but you can't see the wires themselves.

    [​IMG]

    This is what it looks like underneath.

    [​IMG]

    The black bus wires (to the next module) are actually medium duty speaker cable.

    Cheers
    David
  4. SeriousSam

    SeriousSam Member

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    Thanks for the help. Lets say I will only use one power pack. Can I hook up all the wires from that one power pack? Will it be enough to charge the entire length of the track? I plan on running just one train at a time. I will have a yard, but i will have isolated joiners, so it will have its own power pack. Also, there will be a few up and downhill sections that will require some power.
  5. DavidB-AU

    DavidB-AU Member

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    Yes. You just need a switch on each bus wire to isolate or power each block as required. There are several topics in the Technical Q&A section on block wiring.

    Yes. Copper speaker cable has a much lower resistance than nickel silver track. Let the bus wire distribute the track power around the layout and feed the track from it at appropriate intervals.

    Cheers
    David
  6. viperman

    viperman Active Member

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    Do you have any close up shots of the joints with the solder, as you have described them? I have an idea what it looks like, but would like to see it with a close up shot, so I can really get a good idea for it
  7. DavidB-AU

    DavidB-AU Member

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    I don't think I took any close ups. This is rough sketch (not to scale).

    [​IMG]

    The joint is soldered on the outside of the rail with a good quality liquid flux. The solder spreads out nicely across and into the joint and into the metal joiner, but is relatively thin so it gives good electrical continuity but isn't obtrusive.

    A drop of resin flux on the base of the rail joiner before tinning will give a good blob of solder for the (tinned) feed wire to adhere to. Then you only need a very quick application of heat to solder the wire to the joiner, so no worries about melting any plastic.

    Cheers
    David
  8. viperman

    viperman Active Member

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    That's a good setup you have there David. I may look into doing this eventually. One question: I'm sure you already described it, but what purpose does the terminal block serve? Is that to have different blocks wired up for different power supplies? I know a good amount about electricity and wiring, and I have feeder wires every couple feet on my layout, but never once used a terminal block, and it does just fine for me. Oh, on a DC system