Wiring under your model train layout

Learn to wire your model train layout like a pro! Thanks to some simple tips and tricks from our specialists.

Wiring under your model railroad, the lifeblood of every model railroad! We tell you our secret to a fault-free model railroad! It's really not difficult to wire your model railroad properly. With a few simple tips and tricks, any layman can properly and safely supply a model railroad with wires, cables and as we call it a decent infrastructure! At Domburg Train Support, "installation engineering" as we so nicely call it is our daily work. Since 2015 we have been building, automating, overhauling and digitizing an average of 3 to 4 model railroads per year. And to this day, all of those tracks are still running their rounds trouble-free and trouble-free.

How do we wire under the model railway? That's no secret, and in this blog we'll help you get started with our FREE online training in installation technology at the DTS Academy.

Why is wiring so important?

A question we get asked regularly, and rightly so. Technology has been an underexposed and underappreciated aspect of our hobby for years. Somehow we should be glad about that because we earn our living full-time by refurbishing this technique. And even though it is a livelihood, we think it is extremely important that there is good education about the installation technology under the model railroad. Many people do not realize that not only can not properly installing the technology lead to a not properly functioning model railroad, also fire and electrocution danger should not be excluded. We may be working with safe voltage, but currents are anything but harmless. A current in a short circuit has an infinitely high current (Ampere), which is why we can use it to weld and melt metals, for example. This is limited by, if you do it right, the power supply cutting off, or the wiring burning out. And we don't want that on a wooden model railroad.....

What is the secret to a safe installation?

Die is er niet, althans het is geen geheim. Sterker nog, later zal je merken dat het allemaal logica is wat we vertellen. Alleen zit er bij mij een stukje vakmanschap bij. Met ruim 25 jaar ervaring in de installatietechniek merk ik dat het bedraden van een modelspoorbaan voor mij even simpel is als ademen. En daarvoor heb ik wel wat geheimen die ik graag met jullie deel.

Let wel op, installatietechniek wil niet zeggen dat je veel verstand hebt van modelspoortechniek. Ik weet dan misschien op het gebied van bekabelen en bedraden veel, op het gebied van digitale modelspoortechniek was ik in het begin een echte “leek” (Vakterm voor onbekwaam persoon). Voor mij was dit maar aba, dat digitale. Ik weet perfect hoe je een Dahlander motor moet aansluiten, hoe je een rechtsdraaiend veld moet creëren als een pomp de verkeerde kant op draait. Maar vraag me niet hoe zo’n decoder werkt.

Ik heb dat inmiddels wel geleerd, hoe? Gewoon door te doen. Wees niet bang en wat ik vooral gedaan heb, is vragen. Vraag de mensen die de techniek bouwen, die ermee werken en ga met die kennis zelf testen. Mijn eerste onthulling is even simpel als waar: Wie bang is fouten te maken, leert niets en blijft dom

A few simple rules of thumb

Before I start telling my secrets, I will first show you some building blocks that will allow excellent wiring under the model train layout without fear of having to replace it in 5 years.

Use good quality products for wiring under your model train layout

Actually quite obvious. Yet we often see plenty of Chinese imports, electronics especially, or products from the hardware store such as solid installation wire and terminal blocks without conductor protection. Quite a waste and the reason of cost saving is nonsense! Online shopping is often cheaper....

Wiring sleeves and tie backs give peace of mind

Eyelets, staples, nails, we see them often enough. Wire hanging loose, or stretched. The source of many malfunctions. Not to mention order and tidiness. The chance of ripping a wire is very high, and for this reason alone we use simple tools such as tying clips and wiring sleeves to store wires safely and at rest. In the process, wires get hot when you put a heavy load on them and then copper expands, when stripped they cool down again. When the weight of the wire hangs with this, sooner or later it will collapse and that will lead to wire breaks.

Always use flexible cores

Onze grootste doorn in het oog is het gebruik van massieve installatiedraad als bedrading onder uw modeltreinbaan. Nog even los van de bewerkelijkheid ervan is het voor gebruik van digitale spanningen uitermate ongeschikt. Dat is te wijten aan een natuurkundige factor genaamd “Skineffect“. Hierbij verplaatsen de elektronen zich niet zoals je zal denken door de kern heen van de ader, maar langs de zijkanten omdat deze in het midden worden tegengewerkt. Hierdoor verplaatsen zij zich naar de buitenkant van de ader. In het geval van een digitale spanning heeft een massieve installatiedraad van 2,5 mm² de geleidingscapaciteit van 0,5 mm². Gebruik je daarentegen soepele aders dan geldt het effect voor elke ader afzonderlijk. Hierdoor werken hoogfrequente spanningen beter op soepele aders dan op massieve aders.

Speciale dank gaat uit naar Drenth Design & Consulting voor hun onderzoek naar het Skineffect bij Digitale DCC toepassingen.

Always work in star form

The use of a star-shaped layout with central distribution points improves reliability and productivity. On the one hand, it is simpler to construct, less error-prone and therefore cheaper. On the other side in case of failures, it is easier to disconnect sections and exclude clusters from the failure. In almost all cases, it is more efficient and better to install wiring in star form.

And now for the big secret....

Ik durf glashard te beweren dat ik de bedrading onder uw modeltreinbaan foutloos kan aanbrengen zonder tekening, zonder draden te coderen, zonder schema’s te tekenen en zonder te onthouden wat ik gedaan heb. En dan ook na 10 jaar een storing gemakkelijk kan vinden. Hoe ik dat doe? Het grote geheim van mijn werk is:

STOP THINKING!

What nonsense, I can hear you thinking right now. And that's where it immediately goes wrong again, the thinking has to stop. The first thing we learn in our profession is to automate your processes. Because when do we humans make mistakes? Right when we start thinking. Not convinced?

Simple exercise:
Pay attention to your breathing, how long does it take for you to forget to breathe?
Pay attention to how you walk, do you still walk straight or do you start huffing?

Just very basic exercises of processes that we as humans usually perform flawlessly 24/7 without thinking about it. That is directly the blacksmith's secret, automate your process and stop thinking about it!

I can hear it, I need to explain a little more specifically what I mean.

My method for wiring under your model railroad
step by step

Before I start with the wiring under your model train layout I first make sure I have decided on some elements:

1. What colors of wires will I use?

When you get started, it is useful to choose a particular color of wire for each function. As a rule, there are 11 different colors available. Above all, choose colors that contrast with each other. So no red/brown or pink/white, then you have to think again under the track which color you really see, your brain will easily fool you.

Just as an example:

• Digital A (Sometimes P, O, K or simply +) the color red
• Digital B (Sometimes N, B, J or just -) the color black
• Supply voltage 0V (GND or Ground) the color blue
• Supply voltage 12V+ the color yellow
• Supply voltage 18V+ the color gray

The 0V of all supply voltages hang together!

So now you don't have to think about that when wiring. In addition to power wires, we also think about the consumers:

• 3 colors for magnetic coils depending on the manufacture
• 2 colors for the rails, 1 for the continuous rail and 1 for the busy signals.
• 1 color for point piece polarizations
• 1 color for signals
• 1 color for lighting

And so you could go on and on. Above all, define colors in a way you find convenient. After all, the point is not to have to think about what the function of a color is when you see it. And that varies from person to person.

2. Determine wire thicknesses.

I use the same diameters of wire for all jobs in Z, N, TT and H0 scales. Because then I do not have to think about that during the installation of the wiring

Power distribution: 1.5 mm² flexible wire, so from power supply/booster to the distribution points (clusters)
Power supply decoders: 0.75 mm² flexible wire, think of busy signal modules, switch and signal decoders, etc
Power supply consumers: 0.2 mm² flexible wire, think of the indicators, blocks, turnouts and signals

The wire thicknesses are also easily distinguishable from each other, which also minimizes the chance of error.

3. Define your clusters

4. Apply a main piping route

Now I lay a wiring duct from the feed point along all the distribution points. This will be my main wiring duct. Through this run all the power supplies and any consumers such as detectors, coils, signals and lights.

At a distance of at least 10 cm from this, lay a second wiring duct for data and communication. Think of the S88 bus, RS485, LocoNet, XpressNet or Servo controls.

5. Position all electronics

Under the layout, place all the busy signal modules, switch decoders, signal encoders, whatever you wish. Do this in a place as close to the consumers as possible. You can take a central point to place everything in a cluster, as long as you observe the maximum wire length of 4 meters from the consumers.
The best is to mount the modules as it is so nicely called "decentralized".

6. Connect the front!

Now we are going to start wiring. Not yet the wiring under your model railroad itself, but the front end as we call it. For us, the model railroad has an imaginary dividing line which runs through the components. At the front of each decoder is the power supply and the control, at the back the consumer such as the detector, coil or signal.

First we make the front all right:
A: Bring the power wires from power supply/booster to all distribution points with 1.5 mm2 flexible wires.

B: Give each switch and signal decoder two wires power and two wires digital signal with 0.75 mm2 in the colors chosen from step 1. And bring these to the nearest cluster.

C: Now connect all clusters one by one by connecting color by color to the PTFIX distribution blocks.

D: Apply all communications such as LocoNet, S88n, CAN, ExpressNet, R-Bus or RS485.

If this is successful, which is a matter of keeping colors on, then you are done on the front end. Now comes the fun part, commissioning. Power up the installation and check that each module is working, and that the central unit can communicate with all digital decoders. If you have succeeded in this then the front is ready and the model railroad can be connected to it.

7. Connecting model track

Now we are going to connect the model railroad. Most of the work of wiring under your model railroad. In addition to the clusters, divide this into projects. Don't try to do everything at once, but try to work in small projects. from here on we only use wire thickness 0.2 mm²

1. Solder all the busy signals to the rails and bring them in groups of 8 or 16 to the nearest busy signal module
2. Connect the turnout coils in groups of 4 or 8 to the nearest turnout decoder
3. Repeat this also with the signals

By turning these into small projects and completing them in their entirety, you quickly maintain an overview and minimize the risk of mistakes.

8. Setting up the model railroad

Now comes the fun work, payback for much labor, setting up the model railroad. We no longer have to worry about the power supplies and communications. We completed those on the front side in step 6. The back side we will now complete by telling each decoder one by one what it is supposed to do and testing that all turnouts, signals and detectors are working.

9. Fix malfunctions immediately

Now a coil may not switch properly, or a detector may not turn on, or a signal may not want to light. While testing in step 8 you will probably come across some, it happens to me too. Address these immediately and fix the fault immediately. Important key is that you do not think, that will work. No that won't work, you have to strike while the iron is hot.

10. Enjoy

The layout is set up, everything works, there are no glitches. Congratulations!
At this point you can clean up everything and start enjoying yourself. also immediately throw away all your notes and revisions. from now on you only have two truths left: The computer software and the multimeter.

These are the two essential factors you can build on. If steps 8 and 9 are completed then the software is correct, all components have the correct address and not least, everything is functioning properly. The wiring under your model railroad is in order This is your "zero point." The moment when everything is correct.

The rules are very simple, and you can always depend on them:

A: The software does not work well if the information is not correct
B: The Multimeter never lies, especially the pass-through mode is my favorite.

You may think again

Yet that remains the moral, stop thinking. As you have read I have no secret in what I do, I just know what I do. And there's the difference right there, I do it.

Above all, don't be afraid to start doing it, don't get too busy, don't start thinking up all kinds of difficult schemes in advance and waste your time figuring out how the wires are going to run. Now just let LOGICA do its job and enjoy the nice feeling of getting rid of wires. Really, it works very therapeutically. To create order one will first have to have chaos.

If you want to know more about this now, please contact us. I will be happy to tell you everything you want to know about wiring under your model railroad.

Best regards,
Martin Domburg

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