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Colour Coding – Layout Wiring

Colour Coding – Layout Wiring

Layout Wiring


Colour Coding – Wiring

For anyone new to the world of model railways, wiring up a layout can seem a bit daunting at first. When building a layout the wiring can soon grow as you add more motorised points, working signals, track power feeds, layout lighting etc. It’s best to set up some kind of an organized colour system for your layout wiring. This aids in quicker fault finding if any electrical issues arise. I speak from experience, after being asked to help sort out a friend with his layout. He’d used the same colour wire for all his wiring!! This is not the way to go, as it’ll end up with many frustrated hours trying to track down any wiring issues.

So a good idea would be to use red & black wires for the main track power supply i.e. Red for Positive, Black for negative. For the point motors such as those that come with short wires attached, three colours usually used are Red (Positive), Green (Common Return), Black (negative).  Either way, whatever coloured wire coding you use for layout, stick to it & make a record of what colour wire is used for each thing. Making/drawing a wiring diagram of your layouts wiring is also recommended for any future reference.

For wires for points an example size wire is 16/02mm, & for the main power bus wires for the track something like a 25 strand wire. For a more in-depth look at wiring visit Brian Lambert’s website:

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  1. Harry

    Justin or Iain

    Questions if I may. I am in the process of re laying layout 2 having given up on dealing with all the mistakes of my first layout.

    Considerable thought is going into layout 2 to avoid previous mistakes.

    I have perused Brian Lambert’s web articles ( which have been excellent.)

    A couple of questions with out notice if I may. Brian suggests that droppers to the bus wire ought not exceed 300 millimetres. If you occasionally exceeded that (due to access). Does that present a MAJOR problem.

    Second question – how often should I insert a dropper

    Third (and final question) Question – on the web site is there any PDF documents setting out how to convert points to DCC?

    Many thanks in advance

    Harry – Victoria Australia 3 weeks into a total lock down (including nightly curfew)

    • Iain

      Hi Harry,
      As Brian Lambert suggests try not to exceed 300mm if you can, but as Malcolm has pointed out there are cases where it may be needed to exceed 300mm. So long as you use a decent gauge wire as Malcolm has used, it should be okay. On my layout, i’ve added droppers between roughly one set of droppers per section of track, so roughly around 500mm apart or thereabouts. Don’t rely on the rail joiners as these can fail.

      Have a look in our back to basics series of articles here in the club in the electrics section which should be of help. Kind regards


  2. MalcT

    Hi Harry.

    I don’t see a major problem to have droppers over 300mm, but make sure you use a decent gauge wire. I’ve used 26×0.15 and have some droppers up to 425mm. Regarding how often to fit them, I’ve added droppers to every other piece of track and where the point s are I’ve attached them to all the tracks connected to the point work. Don’t rely on the track joiners for power.
    Regarding the pointwork, will you be using electrofrog or insulfrog points ? There are several topics covering pointwork and point motors on the forum – look under ‘Electrics’ in the ‘Categories’ section listed on the right hand side of the page.

    Hope this helps

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