Model Train Layout Wiring Tips
From My Experience

A Cautionary Tale From Not Following My Own Advice

I had been upgrading the layout wiring on my previous Utopia Northern to add more power districts with their own circuit breaker protection. I already had a PSX-2 and a PSX-4 from DCC Specialties installed from one of my two Lenz boosters.

But I forgot which one.  I had kept the briefest of notes at the time of the original installation a few years ago.  Now I wanted to add another PSX-4 to the second booster. The reason is that, although the railroad was working OK, we were getting frequent shut-downs during operating sessions when an operator forgot to throw a turnout in time.

The only way to reorganize the layout wiring was to crawl around under the benchwork tracing individual wires. With all the layout wiring that has been done for relays, frog wiring, building lights and signalling the underside of the layout is a real "rat's nest".

I'm as guilty as anyone at rushing ahead and not taking the time to organize the wiring properly relying instead on my memory to keep things under control. Well, I just got taught a good lesson!

The only good news is that I hadn't completed adding cable ties so there was some slack in the layout wiring to allow me to trace the wires. Also I had maintained a convention of using AWG 14 red and black wires for the main bus with AWG 18 red and black wires for feeders attached to short lengths of telephone wire soldered to the rails. (A few times I used other colors when I ran out of red and black because wire is expensive. Not a bright idea.)

Wire markers to the rescue

 I remembered from years ago that I used to have some wire markers. They had dried out and been tossed in the garbage. 

Sayal Electronics recently opened a retail outlet nearby in Barrie, Ontario. I drove over and bought a package of wire markers (Gardner Bender 42-028).  These are vinyl coated, cloth material that are self-adhesive so you can wrap them around both ends of a wire or stick them anywhere else for that matter.

The booklet contains 15 sheets of A-Z, 0-15, +,-,/. More than enough for the average layout.

I had chosen names for towns and locations on the layout that start with a different letter so it is an easy matter to set up a convention for identifying the wires. If I'd done this in the first place I could have avoided crawling around on the floor for several hours. There's always the chance of disturbing other wire connections when you're poking and prodding.  I only identified the wires that had to be moved in order to set up the power districts that needed to be added or changed. Bill Payne of our Nottawasaga Model Railway club who works on the signalling wiring with me found another device at Sayal that can generate a tone in a wire to help you identify both ends. It must be like the ones telephone and cable repairmen use. I didn't have enough wires to follow to justify the investment. 

 If you can't find wire markers you can use masking tape and a Sharpie pen or different colors of tape, at least temporarily. If you have to use mixed wire colors to save money. it's a good idea to wrap some black electrical tape around the ends of the wire you're using as your common ground (-).

  • You can also buy electrical tape in a few colors.

I also installed some toggles in the benchwork fascia in some districts so I can turn them off to help locate shorts if and when they occur and they are not obvious to locate. I used one side of DPDT toggles I had left over from the previous DC block control days. I'm glad I did.  When I began tracking the wiring the task was complicated by a dead short that developed.

After sleeping on the problem I tracked it down to a micro switch powering the frog on a turnout in Valleyview where the turnout's throw bar was sliding under the arm on the micro switch  creating a short in one direction when the turnout was thrown. The DPDT toggles helped me narrow down where to search for the problem.

  • Even with DCC it's a good idea to break up the layout into blocks or sections.

Usually you just leave all the toggles in the "on" position until you need to isolate a section. This can also be useful when you're working in a section so that you don't have to power down the entire railroad.

There are a lot more tips and ideas on my model railroad wiring page.

Go to simple Train Detector circuit using a photocell.

Go to occupancy signal circuits.

Return from "model-railroad-wiring" to my Home Page.

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