Hi,
I am in the process of building my first permanent layout and I have decided to use DCC. I have already purchased a Digitrax Super Chief and plan to use radio control. My layout is 19'x23' with a 10' peninsula "around the room" layout for continuous running. I have also purchased the wire for the track bus and feeders and am about ready to install. However, this process quite frankly scares the wits out of me, because I know next to nothing about wiring and electricity. But I want to do it right so that my layout runs smoothly. So I need help. I have searched this and other forums for information but I'm a bit confused.
1. Do I run just one set of bus wires continuously around the room, or do they need to be divided into sections for multiple power districts?
2. What do I do with the end of the wire furthest from the controller?
3. Does the bus connect directly with my Digitrax system?
4. I've seen some mention of using ordinary light bulbs to isolate shorts. How does that work? Do you recommend this?
I apologize - I know for most of you that these questions are elementary and they have probably already been addressed. But, as I said, the more I read the more confused I've become. Thank you in advance for your help - and for those who do answer my questions, assume I know nothing about wiring........and you'll be correct. :)
Pierce
Pierce,
I'm replying (I'm not a regular poster) because I was in exactly the same position as you. I bought a Digitrax Zephyr some time ago and knew nothing about wiring, electricity, digital control and this was my first layout, so I know where you're at.
1. You can have one set of bus wires go around the room if you like. More advanced readers here have implemented dividing their power supply and wiring into power districts. It is far simpler to initially have a set of bus wires.
I bought lengths of 14 gauge RED and 14 gauge BLACK wire for my power bus. I picked one rail to be the left rail and one rail to be the right. I dedicated Black wire to supply the left rail and RED to supply the right rail. I ran this wire underneath my layout directly under the rails. I purchased 18 gauge separate strands of Red and Black wire to connect my rails to the bus wires. I soldered (do you know how to solder - a useful skill!) pieces of the 18 gauge wire from the track down to the bus wire underneath (every 3 feet or so on the track).
2. Nothing. The bus wires do not have to be capped or run in a continuous loop or anything like that.
3. Yes. Your Digitrax system has several connections. The connections marked TRK A and TRK B are to be connected to your black and red bus wires. Please refer to your Digitrax documentation. It provides a pretty good explanation.
4. I've read about it but not used this technique. No opinion, really.
We'll help you out!
Dave
Note that I do NOT have a reversing loop in my track.
I may have a bit more experience than you and Dave but I am certainly no expert. First, I would encourage you to take a look at two web sites: 1. DCC for Dummies (http://www.members.optusnet.com.au/nswmn2/DCC.htm) and 2. Wiring for DCC (http://www.wiringfordcc.com/). Both sites are rich resources for DCC info. The DCC for Dummies site contains a discussion of using auto lamps for short detection.
I respectfully disagree with Dave's statement that "It is far simpler to initially have a set of bus wires." Simpler initially, yes, but more complicated/difficult in the long run. For a layout the size you describe I would strongly recommend segmenting the layout into a few electrically isolated sections (commonly called power districts). This will make troubleshooting much easier since you will only have to look for a problem in one section rather than the whole layout. And if there is a short, it will only shut down the section in which the short occurs. And going back later to retrofit power districts will not be simple.
With regard to your third question, if you do set up power districts, you would have the two track output wires go from your command station to some sort of electrical panel where the power would be distributed through a circuit breaker for each power district. (If I knew how to attach a photo to this post I would show you my panel.) Then two bus wires would leave each dircuit breaker and run under the tracks for the respective power district.
Good luck!
I'm a DCC newbie with a question regarding circuit breakers. What rating should these breakers be? Does someone make a circuit breaker panel specifically for DCC? My layout is much smaller (7X4 HO). Do I really need to do this or should I just run 2 wires to the track?
Not trying to hijack the thread!
Thanks
Todd
Thanks for the excellent advice.
How do I separate the bus wires into sections?
Pierce, probably good to do some additional reading first. Power districts are electrically isolated areas of not only the bus but of the track. There are typically additional components involved such as boosters and district managers (take a look at the Digitrax site since you have their products) which are configured in such a way as to supply power to all sections of the track and if there is a short in one section, power is not interrupted to the other sections.
Anyway, best for me not to add anything more in this area because I don't have the experience. Others can probably give you a better explanation.
Pierce,I'm a 10-year Digitrax DCC user, and I've wired both my home (25' x 50') and my club (1/3rd of an eventual 6300 sq. ft.) layout. Electrically, my club layout is as complicated as can be, while my home layout is as simple as can be.
For starters, let's be clear that there are two busses used, one for track power and one for throttles and accessories (which is essentially 6-wire phone cable). This is all about the track bus, which should probably be around 14AWG.
1). On my home layout, I have a 200' long mainline. I ran 200' of 14AWG red and black wire under the main, and dropped feeders every 9 feet. I have no circuit breakers, no extra boosters (I'm using a Zephyr system only), and no extra wires. The downside is that if there's a short anywhere on the layout, everyone knows because all the trains stop. However, that's not so bad because it lets everyone know that someone messed up, so it can be a lot of fun, too.
At my club, we have 8 boosters and 36 or so Power Shield circuit breakers. We have it set up so that each breaker protects 4 blocks (and each block is approx. 15' long), and each booster powers approx. 4 or 5 breakers. Usually, a short only effects the small area around the derailment, and most people don't know if something is awry.
2). Nothing, although some folks like adding a filter to help reduce noise on the bus. However, this is nothing one should worry about unless one starts to have problems.
3). Yes, of course. The Rail A and Rail B (we use B = Black, A = Red) connectors on the front of your DCS100 tie directly into the track bus.
4). I would not recommend using lightbulbs for circuit protection. We found that they caused too much drain on the system. We quickly switched to PowerShields and have used these exclusively every since. They are now up to the PSX series, BTW, and can be found at www.tonystrains.com.
No problem answering questions, and you may want to join the Digitrax Yahoo! group. There are tons of information available in the archives and a lot of knowledgable people on it.
Dave,I think feeders every 3 feet is a tad overkill (especially with 18AWG wire). Even my 9 foot 20AWG feeders are a bit much. As long as one solders jumper wires at every gap, 12 foot feeder spacing is probably just fine, even with 22AWG. The only thing we have to watch out for is voltage drop and continuity, and I don't think we're gonne get much voltage drop in 12 feet.
Roger, I find circuit breakers are, for a home layout, more overkill. Shorts don't magically happen by themselves, and I have found most shorts happen during construction. Once you're up and running, shorts are a rarity.
I will say that one should make new wiring connections with the track power on if at all possible during construction. I know it sounds kinda crazy, but it's only low voltage. If you're wiring, and you put the wrong wire on the wrong connector, you'll know instantly that you've erred (blue sparks, etc.). The thing you don't wanna do is do an hour's worth of work putting dozens of connections together, then turn it on only to find you have a short somewhere. Then you have to take it all apart to find it. That stinks.
Todd,No, you don't need circuit breakers. I have a large layout, and I don't need them at all (and I run with a crew of three or more). For your layout, you will be fine relying on the internal breaker on the DCC system of your choice. I would just use two wires.
I use Power Shield circuit breakers from Tony's at my club: http://www.tonystrains.com/technews/powershield_x.htm
These can be set for 3, 5, 6, or 8 amp, IIRC, using jumper wires on the board.
Pierce, Cutting the bus into sections is very easy. I use terminal strips screwed into the benchwork.
Say I have my 200' mainline bus, and I want to cut it into halves. Go to the center of the bus (and this is where you're DCC system should be located anyways to minimize volate drop), and screw in a terminal strip of your choice. Cut the bus wires, and screw them to the terminal strip. Up on top of the layout, cut the rail in approx. the same place. Remove any connection to the DCC "brain". Both sections should now be completely isolated from each other.
Run a new pair of wires from your DCC system to two circuit breakers like the PSX's. Run the outputs from these breakers to the terminal strip you attached the track busses to, one each.
At this point, you should have two seperate sections of your layout, each with it's own breaker. If you have a short in one section, the other will continue to run normally.
BTW, for pure trouble shooting, one can just put in breaks in the track bus (as described above) but instead of adding circuit breakers, just wire in a DPDT toggle instead. This way, if you have a mystery short, one can kill sections of the layout until you find it.
I still don't think it's all that needed, tho'.
Paul A. Cutler III*******************Weather Or No Go New Haven*******************
Normal 0 Here’s my view on the subject.
It’s more about how much load current your layout will need to provide, and where? This is determined by the number and type of locos and rolling stock you operate at one time.
On my similar sized layout my booster was located near the center, and I extended two #14 bus circuits in each direction. This gives me four power districts. At first I just connected them in parallel to my booster - 4 wires to “Rail A” and 4 wires to “Rail B”. Use #20 or 22 gauge wire for droppers from rail to the bus, about every three sections of flex track.
This worked fine at first, until 3 or 4 sound equipped locos and lighted passenger cars were running, and then the booster would occasionally trip and shut down.
Eventually, I added a second booster and two Digitrax PM42 power management units. These allow me to individually connect the bus from each power district.
One thing about circuit breakers is confusing. You need a special circuit breaker with the correct specifications to avoid nuisance tripping and to avoid tripping the booster. Therefore, it’s far better to purchase a device such as the PM42, Power Shield PSX, or something similar. Follow the manufacturers instructions to hook it up.
As the others have stated, the bus circuit just ends at the last dropper in that power district.
The bus(s) can connect directly to “Rail A” and “Rail B” on the booster. Make sure to observe correct polarity throughout the layout. It’s best to connect a smaller amount of track, then add to it and test it out as you go. Believe me, when you get the polarity mixed up on a lot of rail, it can be “very interesting” to say the least!
12 volt tail lamps are sometimes used in series with one conductor of a power district. I have tried this and it works well with non-sound locomotives. It is quick and very inexpensive.
However, I found the tail lamps are not useful with sound-equipped locomotives and lighted passenger cars. This is because of the higher current drawn by these trains.
5. How do I separate the bus wires into sections?
Use your layout drawing to determine how you can break it into power districts, about two to four in your case. You could highlight the track in different colors. If you need to you can use different colors of marking tape to identify the bus pairs of #14 cable, going to the various districts.
In general, it is best to isolate both rails of a power district, but follow the manufacturers instructions.
This is the time to determine it you need a “reversing section”. If you do, something like the Power Shield PSX is available, or you can buy another booster with reversing capability.
6-wire phone cable
As Paul mentioned, don’t confuse the track bus with the data network cable (Loconet). The Loconet cable carries commands and power for your throttles and similar devices. It is a no-brainier because you just plug in telephone plugs to make these work.
Last advice is: Buy a good adjustable temperature soldering pencil iron and rosin core solder and flux. It is the best $60 ever spent on model RR stuff!
tpd0418My layout is 19'x23' with a 10' peninsula "around the room"... I know next to nothing about wiring and electricity.... But I want to do it right so that my layout runs smoothly.
as I said, the more I read the more confused I've become.
Personally if I were you I would start with the Digitrax unit and two wires to a single chunk of track. Get all the foibles of DCC (especiallly Digitrax wireless) down pretty good then go from there.