Helpful Tips for Model Railroad Wiring

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Wiring for a model railroad layout – it‘s a subject that can be easy or complicated. I like to manage my wiring so that later on, if need be, I’ll be able to trace each wire back to its source.

Years ago, I developed my own personal wiring color codes along with standardized schematics for repetitious situations that I keep in a “my layout” notebook along with my other layout information. Wire gauge standardization is important, too, as a function of wire length and electrical current considerations. More length and/or more current require a heavier gauge wire.

Related video: Wiring a Model Railroad Track

On large layouts, I’ve used buss wire up to 12-gauge (stranded for easier installation) and down to 22-gauge solid wire track feeders that solder to the outside of the rail, hardly seen. That includes the code 55 rail that I use for my Sn3 trackage. And, I’m a fan of using labeled terminal strips at wire junctions to avoid the “What is this wire for?” problems.

Related video: Model Railroad Wiring Considerations

I like to string wiring neatly into bundles that are tie-wrapped and hung through or under the benchwork, avoiding access areas. Buss wires for track feeders should ideally be run under the primary trackage, enabling the use of short, light gauge feeder wires up to the rails.

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In the old days, block wiring required a feed wire from a control panel to each block. In a large layout, that could add up to a lot of wire! Remember the old “spaghetti bowl” wiring scenarios? If you add switch control wiring, along with signal and accessory wiring, you could end up with a real mess! One of the great benefits of DCC is wiring simplification. I know, I’ve done it both ways!

My suggestion is to be as logical as possible when installing wiring so you don’t end up pulling your hair out later. If you have any specific wiring questions, leave us a comment below or feel free to email me directly at doug@modelrailroadacademy.com. I’d love to talk with you.

More in this series:

So You Want to Build a Model Railroad Layout?
Choosing Model Railroad Track Configurations
Assigning a Theme for Your Model Railroad Layout
Ideas for Unique Layout Concepts
Tips on Trackwork
Helpful Tips for Model Railroad Wiring
Creative Ideas for Model Railroad Structures

Discussion
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14 Responses to “Helpful Tips for Model Railroad Wiring”
  1. Christopher

    Does anyone have information as to what power supply I may need for a HO layout starting as a 4’X8″ but will expand to 16′ long. A loop all the way around the perimeter to start and then expansion for maintenance yard and grain silo, a rail yard and a mine setup. Depending on how that plays out, more may be added. I am going to use flextrack. Switches will be involved as well.

    Reply
    • Customer Service

      >Hi, Christopher. You didn’t say weather you were doing DC or DCC. HO trains don’t take all that much current. As long as you install feeders periodically, a 5 amp supply would be plenty good.

      Reply
      • Robert

        I would say 5 amps is plenty. On our club layout we run DCC with PSX breakers set at default 3.81A, and routinely run long double stack trains (85 or more) and 6 to 10 SD90 locos all powered, with sound and lights. In fact any more than 5 amps for HO can be dangerous when a short occurs. This would apply to DC or DCC. If you are planning to go DCC in the future, or more importantly if you don’t think you will you should wire your layout for DCC. If it will run on DCC then DC is easy, and then it is a matter of just switching the power supply and adding decoders to the locos. For a small layout like you describe I would start with an NCE Power Cab, it will probably be all you need for a long time.

        Reply
  2. Guy

    Bus wire and feeders… Do I have to solder bus wire to rails or is it a loose wire all along layout and only feeders have to be soldered to rails ?

    Reply
    • Customer Service

      Hello Guy, the buss wire would be a heavy gauge wire that carries the layout power around under the layout. Light gauge (I use solid) feeder wires would run short distances from the buss wire to a solder connection on the bottom or outside of the rail. You can use crimp-type (suitcase) wire connectors for the feeder connection to the buss wires.

      Reply
  3. BOB

    I am going to run 18 g feeders from my 14 g buss on my analog HO layout. Is it best to use solid or twisted for the feeders? Should the feeders be solid copper or can you use something else. If something else, what is good as I know there are many different types of copper coated wire. What gauge wire should be used for turnouts, can I use the same 18 g I’m using for the feeders, run on the turnouts is about 10 feet? Thanks in advance.

    Reply
    • Customer Service

      Hello Bob,

      Here’s my view on this. I run my buss wires as close as possible directly under my main lines, then I use a #22 solid wire from the buss to the rail and solder it to the bottom or outside of the rail. The feeder becomes very inconspicuous that way.
      For turnouts, if they are a DC motor type, I use #22 stranded wire as they se very little current. Ten feet is not a problem.

      Hope this helps,
      Douglas MRA Video Membership

      Reply
  4. Billy Mills

    I often see comment about using DCC. But I have yet to find information that I can get my 65 yr old brain around. Any suggestions.

    Reply
  5. griffith436

    I am retired and want to build a layout with my grandson… I have a 12×16 building but I am willing to take all the advice I can get…. I am completly ignorant and willing to learn

    Reply
  6. BOB Carlisle

    Question: I am starting a dcc HO layout in my garage. It will be 3-4X6 sheets with 2 main line loops around the perimeter. do i need a main buss loop for both the inner loop & outer loop or rjust run feeders from both loops down to 1 main buss run?? I am planning on 14 Ga. for the Buss.
    thanks.

    Reply
    • Customer Service

      Hello Bob,

      I would do separate buss loops as you may want to separate them electrically with DCC circuit breakers. A 14 gauge buss is fine, but it might be heavier than you really need.

      Hope this helps,

      Douglas
      Model Railroad Academy Video Membership

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  7. Robert Chiles

    Consider changing your name to HO Model Railroading Academy, because you don’t have anything helpful or useful for O gauge.

    Reply
  8. john bozic

    I used 18 2o through out mine for the gauge. Each wire has its own point of contact and no more then 1 amp of power throughout them. I do not use buss wires and avoid suitcases this way they can become unreliable in time / I have seen this happen on cars so it is better to avoid unwanted issues. I have a max of 5 amps for 9 atlas 205,s at 4 connections each one. and 14 215,s and 5 amps through them at 6 connections each 215. I use the power when needed and each area has tested ok.

    Reply