How much wiring is needed for a DCC layout?

[MisterBeasley]

QUOTE: Originally posted by jecorbett

The idea of isolating sections of track that can be turned off with a switch is a good one and one I hadn't thought of. I just added a small fleet of of lighted passenger cars to my layout and for at least half of my planned operating sessions, they would sit idle in the coach yard. Not only would that put unnecessary strain on the bulbs but it would not look prototypical to have lighted cars sitting in a yard.

Miniatronics makes a package of very small slide switches. I've been installing them in the floor of my passenger cars to turn out the lights. Most of the time, I'll just leave them off, but if I'm running night ops or showing off the layout to friends, then I'll put them on. I'm going to do this for my lighted cabeese, too. My first installation of these was to control the power to the video camera in the front car of my subway train.

When lights-only decoders come down to $5, I'll install them. Until then, this is a reasonable solution.

EDIT - Oh, yeah. To mount these little switches, I drill a 1/4 inch hole in the floor, and glue the switch in with CA.

[AntonioFP45]

Great point, Joe!

I have an MRC Tech II 2500 powerpack. I bought it back around 1991. Cost me $60+ and was worth it. A far cry from the little Tyco and Bachmann powerpacks that get hot in 5 minutes.

With the "Jump Port" feature offered by the Digitrax Zephyr, I'll be able to "plug in" the Tech II to run a 2nd train.

High Greens.

[jfugate]

The more trains you want to run at once, the more efficient DCC wiring becomes.

Also, I'm quick to remind people that when comparing DC to DCC, always pick a pretty high end power pack, something costing $60 or more -- per train you want to control.

DCC comes out of the box with very fine loco speed control, momentum, and the ability to tune loco performance individually for each loco.

Your typical $25 DC power pack has none of that.

[Anonymous]

In theory, just two wires coming from the power set, and a bus. Well, not in theory, it can certainly be done. But blocks should be used to make problem diagnosis a lot easier. From there, it's pretty much up to the operator where to place any blocks. To answer your question more directly....less wires than DC for sure. How's that?

[AntonioFP45]

I want sound in my diesels and lights in some of my Walthers Budd cars, so I'll definetly need at least one booster.

For HO, a friend of mine strongly recommends the Peco "Insul-Frog" turnouts as they help eliminate some of the potential headaches.[;)]

[Texas Zepher]

QUOTE: Originally posted by Stuckarmchairing

Im guessing return loops and wyes still need speical wiring. But do you still have to isolate yard tracks and all the stuff along those lines?

Re-reading all the replies, I haven't seen anyone mention that all this:
If the turnouts have hot frogs getting their power through the points, all those gaps that prevent short circuits are still required. With the extra gaps would be the associated extra feeders, but I don't know if that is considered special or not.

[Texas Zepher]

QUOTE: Originally posted by Allrailsgone
Aren't boosters required for each block

No. Depending on why each block exists, one may or may not want a separate booster for it. If the blocks are just for trouble shooting, once tested that block can just be put onto the bus. If trouble happens just remove the jumper again to check that block. For short circuit isolation, several companies make special units that divide the power. Each block has full power from the booster but doesn't short everything when there is a short in a single block. I use the Digitrax PM-42. http://www.digitrax.com/menu_powerman.php
The only time you need to add a booster is if there are more locomotives (and other current drawing equipment like lighted passenger cars) that need the additional power.

If the blocks are for signalling it falls into an entirely different category, and would depend on the signaling system being used.

[jecorbett]

The idea of isolating sections of track that can be turned off with a switch is a good one and one I hadn't thought of. I just added a small fleet of of lighted passenger cars to my layout and for at least half of my planned operating sessions, they would sit idle in the coach yard. Not only would that put unnecessary strain on the bulbs but it would not look prototypical to have lighted cars sitting in a yard.

[Anonymous]

Aren't boosters required for each block?

[MisterBeasley]

DCC will work (sort of) with a single pair of wires to the tracks. You actually can control a wye or reverse loop with a DPDT toggle switch, just like in DC. But...

You really want a track bus and feeder wires every few feet. DCC can sometimes be sensitive to not only voltage/current issues, but also signal strength for the encoded commands to the locomotives. Even if you are using DC, you would want this kind of bus-and-feeder arrangement.

There are several manufacturers for reversers. I personaly got the Tony's Trains house brand, because they are solid-state (no relays) and provide circuit breaker protection as well. I don't have any experience with others. I know MRC and Digitrax both make them.

The idea of a track you can shut off with a toggle switch is a good one. I put in a few of these, notably the turntable "parking" tracks, but also a couple of long sidings where I can park lighted passenger cars or cabeese to save the bulbs.

[nfmisso]

QUOTE: Originally posted by jecorbett

I wired my mainline with feeders every 6 feet which is every other joint of 3 foot flex track. Some might wire it at every joint but I have had no problems this way. Feeder wires at frequent intervals is good advice for DCC but I discovered something very curious when I hooked up my staging yards. I built the 3 track loops first before I did the mainline. At the time, I hadn't read up enough on DCC to know you should wire at frequent intervals, so I put a single feeder wire at the beginning of the reversing section which feeds all 3 tracks. I attached these to my MRC reversing module just to test it out and was able to run the engine around all three loops with no noticable loss in power or response. That means the current is travelling over 12 feet of track with no feeders in between and performing well. Eventually I am going to install additional feeder wires to all 3 tracks but it makes me wonder if maybe we aren't going overboard with so many feeder wires for DCC systems. Obviously you do not want current traveling over 50 feet of track with no assist from feeders but I wonder if the standard recommendations are really necessary.

With one locomotive, probably no problem. The issue that comes into play is Ohm's Law: V = IR. As you put more load on the circuit (track) the current goes up, the voltage drop will increase.

In practical terms, it may work fine with a single locomotive, but it most likely will not with more locomotives and other loads such as lighted passenger cars.

[jecorbett]

I wired my mainline with feeders every 6 feet which is every other joint of 3 foot flex track. Some might wire it at every joint but I have had no problems this way. Feeder wires at frequent intervals is good advice for DCC but I discovered something very curious when I hooked up my staging yards. I built the 3 track loops first before I did the mainline. At the time, I hadn't read up enough on DCC to know you should wire at frequent intervals, so I put a single feeder wire at the beginning of the reversing section which feeds all 3 tracks. I attached these to my MRC reversing module just to test it out and was able to run the engine around all three loops with no noticable loss in power or response. That means the current is travelling over 12 feet of track with no feeders in between and performing well. Eventually I am going to install additional feeder wires to all 3 tracks but it makes me wonder if maybe we aren't going overboard with so many feeder wires for DCC systems. Obviously you do not want current traveling over 50 feet of track with no assist from feeders but I wonder if the standard recommendations are really necessary.

[AntonioFP45]

An example of a good post from StuckArmChairing.

Initially I was confused but after reading the step-by-step info that's available on line and seeing it on my friend's layout, it is very straight forward.

[conford]

The wiring you need is as little as two wires to the layout, for a small layout, or more fror a bigger layout. The wires need to be able to conduct enough power to run all your trains, so think big (up to 12 ga. for HO). If you are building a new layout, you can run a power bus wherever you are going to lay track, and then wire the track to the bus as you go. It is good to have sections of the layout you can shut off for troubleshooting purposes. Also, short protection protects your exuipment and can keep the other trains running when there is a short. See www.wiringfordcc.com for plenty of information.

Enjoy your trains,
Peter

[BR60103]

I think you should always plan blocks into a layout, even if it's just for debugging the wiring.
And I think dead sidings or loco shop tracks are really useful. Some sound units insist on starting up in "on" mode, and after a short, all the sound equipped locos start burbling away.

[rrinker]

OOPS! [:I]

That's OK, the first time I had the opportunity to run a DCC system was at a local train show, a vendor had a small loop of track and was running two locos with a Digitrax systen. Now, i was fully aware that both these locos were on the same short piece of track and everything, but what I was NOT aware of was how much momentum was programmed into one of them. OOPS! Although they did not hit very hard, the one still moving WAS coming to a stop. So far I have not repeated that with my own equipment, even on my test loop when I had 3 locos running at once, no mean feat since all I have for now is the built-in throttle on the Zephyr.

--Randy

[mcouvillion]

Randy,

The first time I saw DCC in action I had just arrived at the railroad with several other guys. The owner and another fellow were running two trains and stopped paying attention to them to greet us, just like they would when runnning on DC on this layout. About the time we all entered the layout room, we heard a loud THUNK as the two (brass) trains met head on on the main at the far side of the layout. It became very apparent that with DCC you really have to run the trains!!!!

Mark C.

[rrinker]

QUOTE: Originally posted by Stuckarmchairing

I know this might make a lot of you vets roll your eyes,but bare with me here.Is it possible to run two trains in different directions on a single track with DCC?

This is probably the best reason to even USE DCC - because you can do this. 2 trains, 3 trains, up to the capacity of the DCC booster (and how many trains physically can fit on your track). All without block toggles to keep flipping as your train moves down the track. With DCC, you just run the train, you don't have to worry about keeping up with the block toggles. On some busy railroads you would end up spending so much time flipping the toggles, you'd never even realize what train you were running.
Of course there is a downside - you can easily have cornfield meets if people aren't paying attention. But since you will be looking at your train and not at some control panel, it's not that big a deal.

--Randy

[Anonymous]

These guys are giving good advice. The only thing I did different was I did put one track that I could kill in case I wanted to park a DC loco on it while I ran others on DCC.

[Anonymous]

Yes it is ,with dcc you can control each engine seperate from each other.When you wire your track you should put feeders at every connection,also with wye's and loops you need to isolate at both ends and make sure that the part being isolated is as long as the longest train{engine tender}or a diesel with all wheel pickup} in other words you don't wont one truck crossing into isolated track triggering reverser while the end truck is still on the main. The track wiring itself is not that much different than normal dc just make sure that all the outside rail is powered from the same lead and the inside rail from the other lead.Iam sure you will recieve many reply's on this topic for there are a great many people on this forum with a wealth of knowledge,some one will explain it alot better than i can but for now I hope this info helps you out.Also allmost every major Manf.of dcc NCE ,LENZ, DIGITRAXX ,CVP
makes there own acsessories such as reverseres circut protectors as well as places like TONY,s train exchange LOYS TOYS just to mention a couple these also can be a great sourse of info.Check it out once you run in DCC ,you won't settle for anything less.

[Anonymous]

I know this might make a lot of you vets roll your eyes,but bare with me here.Is it possible to run two trains in different directions on a single track with DCC?

[mcouvillion]

StuckArmChairing,

With DCC, you want power everywhere all the time, so the yard tracks and sidings are powered just like the main lines. For loops and wyes, MRC has an auto-sensing device that will change the DCC polarity to match that of the engine entering the loop or leg of the wye. You must isolate the loop and/or wye at both ends completely from the other rails, and power it from the MRC device (I don't remember the part #). Basically, you can run a pair of wires from the power source (the bus) and drop track feeders to the bus. As long as you don't cross-connect the wrong rail to the other side of the bus, you really only need two wires. Other considerations may cause you to run more than one bus, but the simplest solution is a wire pair.

Mark C.

[Anonymous]

Im guessing return loops and wyes still need speical wiring. But do you still have to isolate yard tracks and all the stuff along those lines?