Ok, I have been reading, reading, reading all over the place about DCC, including reading users manuals. I now have a very good understanding of how the system works and what all it can do.
My question is now…how do you wire it all up??
Where is the reading and illustration material for all that?
I want to know what feeders are, when you have to add a booster how do you wire your layout to make Power Districts, different gages of wire for which applications, wiring for reversing, turnouts, what double gapping, etc…?? Can anyone post some links to threads that talk about this, books or other materials that discuss and illustrate how all that is done and how it’s done properly??
I’m going to be starting my own model railroad shortly and I know I want to use DCC, I now know the in’s and out’s of how the system operates, I still don’t know how to wire it all up.
If anyone would like to explain it to me please remember I don’t know so explain it in simple terms or post links that does explain it in detail so the average Joe can understand it. Labeled pics would be awsome.
You will need a robust set of wires coming from the main power posts of the DCC controller station to follow, sort of, the main path of the track…like you main line. It will be stapled, or bracketed up at intervals to keep it tidy. Those two wires are you bus, and they should come to a dead end nearly all the way around the main…BUT NOT coming back as a loop to their posts on the controller. Cover them for safety with end caps, tape, whatever, and tack them up.
Coming off each wire of the bus that I just described…and you have a good idea which wire is pos and which neg…right?.. you solder smaller gauge wires as feeders and put them up through the foam or plywood to be soldered to their right rails…for polarity sake.
That’s about it. Your tracks, each rail, should be gapped at three-six foot intervals, and each segment should get one set of feeders. Read Joe’s DCC clinic or visit his forum and find how to wire 12 v auto taillight bulbs in series into each of these segments to control shorts.
So…in converting from my DC to DCC…my N gauge layout is very small…i.e. about 3 x 6…
wire the common feeders s to one bus and the remainign feeders to the other buss…
I have a short reversing loop and will need to use a Digitrax AR-1.
decoders.
Does this sound correct? Anything else I need to consider.
Sam
BTW…I find the forums adding to my understanding of so many of the facets of model railroading…my thanks to the many contributors for making my modeling experience a bit easier and also a bit more challenging
I’m not in DC, so I don’t know what you mean by “common”. The word amongst DCC users is that common ground is NOT good for that setup.
Lay the track (already done), and then gap it every 3-6 feet. Each rail should have A feeder wire in each gapped segment. One wire goes to the, say, black negative wire in the bus that comes from the controller, and this is repeated in all segments. Similarly, each segment’s positive wire, say red, goes to the other wire in the bus.
If you end up setting up power districts using boosters, now you need a sub-bus (I believe). Hopefully you don’t have to do all that work.
Gap your entire reversing loop to separate it at both ends from the feeding turnout. That is, gap at the diverging route as it leaves the turnout, and gap the through route as it leaves the turnout. Now you have to treat that loop as a powered segment or your trains won’t run on it. So, you feed power to the AR, and then power from the AR to the individual rails. The beauty of the AR is that on this segment only, you can cross the feeders and nobody cares. If you cross the wires, it will reverse polarity, as it was meant to do, when the loco makes contact.
I don’t use stationary decoders, but it should be straight forward. They should get their signals from either the rails (probably not a good idea) or from their own sets of feeders, and then they have fine wires to the decoder.
Crandell wrote:
“Those two wires are you bus, and they should come to a dead end nearly all the way around the main…BUT NOT coming back as a loop to their posts on the controller”.
JB says: Wow…When I was at the NMRA convention in SJ …Both AJ Ireland of Digitrax and Loy Spurlock of LoysToys suggested that returning the loop back to it self, would assure good voltage, everywhere without a possible drop anywhere! Has something major changed sense then?
I didn’t do "the loop"buss on the CCRY (even though I was trying to figure out how I could do so) as I ended up dividing the pike into four power districts (upper, lower, peninsula & helix) and returning the buss to it self wouldn’t have been practical…or EZ to do.
I think the loop electronically is not a good idea, but will also probably never cause a problem. I would lay the bus in both directions from the controller, but not connect it to itself at the point farthest away. If you close the loop you essentially have signal races so that there is interference of the signal with itself. BUT, the DCC signal is slow enough, and not really susseptible to noise, so it will probably never be a problem.
The idea that looping the track (power) buss will cause problems is a myth that just won’t go away.
Think about it for a minute: If you have a loop of track, and feeders from the buss to the track, you’re just using the track itself to electrically close the loop in the buss.
The bottom line is that having your track (power) buss in a loop causes no problems whatsoever.
Just keep in mind that the same does not apply to the command (throttle) buss, because it’s electrical characteristics are different. It shouldn’t loop back on itself. I think this is where the confusion comes from.
WOW…thanks guys, this is exactly the info I’m looking for, detailed from starting point to ending point and what needs to be done to get it operational.
Ok, what I didn’t see is…what gage wire for the bus line, what gage wire for the feeders, what gage wire for other things like accessories (crossing gates, building lights, etc…)
Also, where do you aquire these gage wires…hardware store, hobby shop, etc???
I thank each of you greatly for replying as you all are really making me feel confident in getting started. I have to say I’m very excited and most likely next weekend, finally going to get the materials to build the table. Soon after laying track and since i want DCC from the start, why I’m asking for help and I do appricate everyones help. If there is anything else anyone can think of I’d need to know, feel free to reply and tell me.
If your track makes a loop, with no gaps, then that’s absolutely correct. And I think that you are correct that a loop on the bus side is never going to cause problems. But, that does not mean that it is a good thing to do. The same thing that makes a loop a bad idea on the throttle bus still applies on the bus, but because the signal is big and slow, the interference is not a problem. But if the timing of the signals was on the edge (and the spec is wide enough that that should never happen), then the potential of signal interference from the loops does exist. With a long enough loop, a nearly out of spec controller, some dirty track, and the wrong phase of the mo
Your builder supply, corner hardware, Home Depot, etc should all have plenty of what you need. It is common stuff.
As a general rule, and I am sure you can take it that you fall well within the guidelines, your two bus wires (one off each post) are best in the 12-14 gauge range. If your bus length is going to exceed 50 feet, maybe you’d be better upgrading to a beefier 10 gauge.
As for the feeders, none of them should exceed a couple of feet in length, ideally, so you could get away with as thin as 20 gauge, but 18 would be a bit better for voltage drop to the tracks…only a very little bit. The issue with the lighter feeder guage is when a short occurs in that district or segment and a lot of current gets sucked down those thin wires. I think a thicker gauge with resist heating too much if you are a bit long in shutting off power. I may be incorrect, and if so another person will set us straight.
Great, so it seems what your saying is that the higher number of gage, the thinner the wire. 12 or 14 for my main bus and 18 for the feeders. Everyone else agree with that??
I wired the main power feeds from the unit to a terminal strip. Then wired same size wire busses in multiple directions from that terminal strip ending in other terminal strips. These runs are shorter and tend to eliminate any voltage drop problems. The track feeds are lighter gauge from the sub-terminals to the track. It’s seems to be easier to move the feeders if necessary and, hopefully, easier to track any electrical problems (haven’t had any yet).
I agree a loop shouldn’t cause a problem and remember this is AC so the polarity changes, 60 times a second.