Simple DCC Wiring Guide


RJasonB

ITS_MFRR est. 2010
Can anyone recommend a simple, online, how-to guide to wiring a layout for DCC? I am considering a major overhaul on my layout which will convert it from Kato Unitrack (pre-wired feeders) to flex track. This will require that I learn a few new things, which is always a good thing. However, while many of the online guides, such as "Wiring for DCC" and "DCC Concepts" are informative, they tend to read like a dissertation. My eyes burn and my brain sizzles before I get to the basic information I seek. At this point, I am looking for "how" instruction as opposed to the "why."

Thanks! Jason
 
Not so Techie DCC Info

I've found these two sites to be informative and easily searchable.

dcbydesign.com

dccconcepts.com
 
I am considering a major overhaul on my layout which will convert it from Kato Unitrack (pre-wired feeders) to flex track.
I am missing something here. Why would that change how you wire the thing?

However, while many of the online guides, such as "Wiring for DCC" and "DCC Concepts" are informative, they tend to read like a dissertation.
That is because if it is difficult they can sell more books. Stop trying to make is a strange and mysterious thing.

I am looking for "how" instruction
DCC controllers generally come in 2 or 3 pieces. First the power supply that converts 120VAC to the train power, the DCC controller that produces the DCC signal for the track, and finally the throttle. The Power supply has to be connected to the controller. This is often just a plug in arrangement. Then usually the user has to provide two wires to run from the controller to where one would have previously had a DC cab. Make certain all other cabs are disconnected just as a safety precaution. Then plug the throttle into the DCC controller and the trains should run. Once you get a train running then look for problems and determination if you need more wires (the locos slow down, loose power or signal) or heavier wires (because the circuit breaker won't trip), or even a bus (more and heavier wires). Unfortunately the WHY determines the HOW. Different layouts are going to need different wiring.

How to wire a throttle bus is going to be dependent on the specific DCC system you have choosen. Personally I have gone wireless just so I don't have to mess with throttle buses anymore.
 
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I wired my layout as a single cab DC layout. I then proceeded to operate it as a DC layout for a while.

Then, when I was ready to make the transition to DCC, I disconnected the two track bus wires from my DC power pack and connected the two wires to my DCC controller. That is all that was necessary to convert the layout from DC to DCC.

It can be somewhat more complicated if you have a large layout. For example, you may need boosters to handle the current requirements if you will be running many locomotives at the same time. Or you may wish to set up power districts so that a short on one part of the layout does not shut down the whole layout.

Are there some specific concerns that you have?

- Jeff
 
Thanks for the input, everyone. I operate using NCE Power Cab and have been for about three years. Kato Unitrack uses 24 AWG wire for the feeder tracks and extension cords. This has proven to be a limitation as my layout has grown in size and number of operating locomotives. My post was intended to generate a simple how-to guide for installing a power bus and dropping feeders. I get that the 'why' leads to the 'how,' but much of the 'why' out there is long-winded. I've decided my approach to the "how" will be "just do it."
 
Hi Jason -

Based on a combination of personal experience and advice received from others, here are some basic wiring recommendations. Others may have different opinions, and I hope they will contribute their thoughts to this thread.

1. Run a pair of heavy gauge bus wires around the layout. Use stranded or solid wire ranging from 18 gauge for a small layout up to 12 gauge (or even larger) for a large layout. The bigger the layout, the larger the bus wires should be. The two ends of each bus wire should NOT be connected together to form a loop.

2. Feeders should be 22 gauge or larger. If you can keep the feeders short (a foot or less), 22 gauge is large enough, at least for HO scale and smaller. You may find solid conductor feeders to be easier to handle, but stranded wire is fine if you prefer it. The stiffness of solid conductor feeders may make them easier to position for soldering to the rails and easier to push through small holes in your base board.

3. Install feeders for each section of track and each turnout. This may seem like overkill, but you will not regret it.

4. Solder feeders to the rails. Do not use terminal rail joiners.

5. Connect feeders to the bus wires either by soldering, using insulation displacement (suitcase) connectors, or with some other reliable means such as Posi-Tap connectors.

6. Use turnouts with frogs that are isolated from the rest of the turnout. Provide a means of powering the frogs (and switching polarity), especially if you run short wheelbase locomotives.

7. Do not depend on rail joiners to carry power between track sections. Rail joiners are great for keeping rails in alignment, but are not reliable for carrying power. Even soldered rail joiners can become poor conductors over time.

- Jeff
 
The two ends of each bus wire should NOT be connected together to form a loop.

Sry not to hijack this thread, but why not? Does this cause some sort of issue with the DCC system? I have my bus wire loop connected at the ends. I am running DC right now but plan to go DCC very soon so I will cut the loop if I have to!
 
Hi Beagle -

The explanation I've read (in several places) is that since a closed loop bus provides two possible paths for DCC control signals to reach a given point on the layout, interference can result. For the same reason, it has been suggested that your trackwork should have a few insulated rail joints, even if your DCC layout is wired as a single power district.

Another point to add to my earlier post is:

8. Twist the two bus wires together to form a "twisted pair." Every DCC "expert" site recommends this to combat stray inductance.

- Jeff
 
T I operate using NCE Power Cab and have been for about three years. Kato Unitrack uses 24 AWG wire for the feeder tracks and extension cords. This has proven to be a limitation as my layout has grown in size and number of operating locomotives.
Ok that is information we can use to help. Simply run a two wire bus the length of the layout. Often people will run the bus directly under the main line. Depending on the length of the bus will determine the size of wire needed. Most use 14 gauge (fairly cheap and easy to find, which is usually overkill, but "large" layout means different things to different people). Position and attach the DCC power unit 1/2 way through the bus. Add a new Kato feeders to your track about every 3 feet. Connect the all feeders to the bus by the shortest length possible. With that many feeders, the Kato standard 24AWG should be sufficient. Any loco will never be more than 2 feet from power. If a lash up needs more power it can pull it from the feeders on either side.

Once again don't make it harder than it has to be and invent problems that don't exist.
 
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The OP didn't type in the address correctly in the first place. He had it as "dc" vs "dcc". :rolleyes:
The other address I already posted. His web site's home page has problems, not showing other links though the rest of his site seems to be ok.
 



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