If you use DCC, what gauge wire do you use for your track feeders and are they solid wire or stranded?
Solid wire. Go with the largest you can feel comfortable with aesthetically when soldered to the outside of the rail. Fo HO this might be as large as #18 (although I would go smaller), for N maybe #20. I'm quite happy with #24 (telephone wire) for N scale. Hard to see once the rail sides are painted. My bus wires are #12 however.
I model in HO scale. I use #12 and #14AWG STRANDED bus feeders under the layout. I create electrical nodes at each feeder point w/ a common screw terminal. Then continue the bus onto the next terminal and so on. For feeders, I use SOLID #20 or #22. I use a technique I read somewhere about disguising the feeders as track spikes. That is, I cut the wire at the work bench at a length that will reach the terminal below. Then I strip it about 1/2" or so. Then I put the bare copper on the flat of my bench vise and pound it flat w/ a small hammer. I then take needle nose pliers and bend the end of the flat copper to resemble a track spike. I drill a hole in the baseboard adjacent to the rail, poke the wire through and hang the "spike-looking" feeder on the flange of the rail. With a minimal amount of flux and solder, it gets fastened. I take the other end and hook it to a bus terminal below the layout, and VOILA, I am done. It takes no time and easily disguises the spike... uhhh, I mean feeder pretty easily. My color coding is red and green for my track. That is, I call red my "hot" (usually the leg that is switched) and green I use for common. (Typically associated w/ ground). Color makes no difference AS LONG AS YOU ARE CONSISTENT. When I was in college, I had an electrical engineering project that required I build and program a security system. Somehow, I wound up with a 300 ft spool of two strand, #20 AWG red and green copper. (Someone actually gave it to me). I used maybe 20ft on the project and have used it since on my layouts.
Jim, I'm already using 12 ga. for main busses. My question was about track feeders. What gauge feeders do you use and are they stranded or solid?
So you model in N scale and you use phone wire? I'm really curious about this, as I have a bunch of phone wire. However, my primary power districts with 12 ga. busses average about 25 ft long divided into 4 secondary power districts using 18 ga. wire. I plan to attach feeders every 5 ft. via rail joiners soldered in the middle of 2 pieces of Atlas C55 flex track. They then would be isolated (no mechanical connection) at each end. I want all bus wires to the front of the layout, so feeder wires will have to be at least 8 in. long with several longer yet. My layout is centered around a helper operation on a 2 1/2 % grade virtually all the way up the visible mainline. This being the case, I can see as many as 24 engines within a main power district. Downhill traffic will of course be drawing less current, with the uphill doing the opposite. I suspect the track feeders to, on occasion, be occupied by as many as 8 engines. My common sense seems to be telling me that this could be quite a load for telephone wire. NO?
Keep in mind that with DCC, common rail wiring is discouraged. Power districts are separated by gaps in BOTH rails so "direct home" wiring is the norm.
I use phone wire (#24 solid) for the track feeders only. My busses are #12 stranded. Feeders are every 3 ft (average) and soldered directly to the rail. Feeder length is never more than a foot. Since there are mutiple feeders for each electrical section of track, they are effectively in parallel so no one feeder carries the entire load. As an aside, I would be wary of feeders soldered to rail joiners unless the joiners themselves are soldered to the rail. If there is not a soldered connection to the rail, over time there will be oxidation or other crapulation which will cause problems, and once painted and under the ballast, finding a bad feeder is next to impossible. Solder!!!
Because my Unitrack layouts are temporary, I use Kato's own wire which has Molex like Mini Tamiya/Kyosho connectors. They use 22 gauge stranded two-conductor wire; blue/white for track power and red/black for switching. I made my own adapters for my Digitrax Zephyr. I want to make a 7' track power extension with female connectors spaced every foot or so. I'd like to use blue/white wire that matches Kato's but I can't find the wire in bulk. Walthers has the red/black, and a few other colored pairs, but not blue/white. The guy at Kato USA's tech support suggested I cut Kato extension cables... an expensive waste in my opinion. If anyone knows where I can find blue/white stranded pair on 25' or 50' spools please post the source here or send me a private message. Thanks!
Our T-Trak sub-division needed to do something similar. Check out: http://www.nvntrak.org/t-trak/T-TRAK_PowerPole_Feeders_Draft-7.pdf The wires may not be blue and white, but the connectors are!
Doug, I've got the main and secondary busses figured out, its the feeder wires I'm concerned about. Using Atlas C55 track, I solder 2 pieces together using rail joiners and then will solder a feeder to the joiner. This makes for a 60" feeder block with the feeders in the middle. The 60" between feeders is almost double the distance that you have, but the potential power draw will be the same regardless of that. I suspect that 5 engines consisted together physically (and electrically or course) will be the max that may occupy a feeder block at any given time. It will be difficult to keep all the feeders under 1' long because it is my intention to keep all main and sub-bus wiring to the front of the layout. Plus there's about a 6" vertical drop just to get to the level of the bus wiring, then feeders will have to be run to the front of the layout. Keeping them under 12" may be a bit of a problem in a few locations. I think maybe I'll try phone wires on a block or two and see if its going to be workable. Yeah, I had a problem with that "common" terminology also, and yes I solder everything.
Our main track supply for our club layout is just getting wrapped up with 10 ga. solid copper wire, which makes me laugh because it is heavier than most of the wire in my own house. We will be installing track feeders using mostly telephone wire. The 10 ga. decision was made because one of our club members managed to get some fairly large spools for free. That's hard to beat.
Good deal! Keep in mind that home wiring is 115V, so a 1 volt drop is less than 1%. DCC is about 14 V, so the same amperage draw as above will result in the same voltage drop, but a 1 volt drop is now a little over 7%. That's why long distance power transmission is at 50KV rather than 12V!
Rick, 24 stranded (it bends better) guage will do fine as long as you don't go over about 3 feet from your buss line on your drop feeders. Feed your drops for every piece of track, as long as your main buss line is heavy you shouldn't have any problems with resistance drop. Think of it like a water pipe, the larger the pipe the more force you can deliver to each home (drop line) and the resistance under 3 feet is minimal. I on the other hand do O scale and am into overkill with # 8 main buss line and #20 drop wires at terminal blocks.
Connection to bus I plan to install bus wires to my 4X8 starter layout when the benchwork is finished. Please excuse a really basic, newbie question: how are items like street lamps, structure lights, etc. connected to the bus wire? Please keep it *really simple." Assume nothing:tb-rolleyes: eagle37
They're not. (how's that for simple?) Accessories such as those you mentioned generally are powered separately (maybe via feeders to a separate bus), and not from DCC power (save that for locos).
Eagle37, Run two busses. One for DCC and one for accessories. I would use different colored wires so you don't connect to the wrong buss.
That's a good point. These decisions were almost all made before I joined, and I don't mean to look like I am Monday morning quarterbacking any of them. I think we could have gotten by with 12 ga. wire just fine, but the 10 ga. was had at the right price (free) and given the lengths that some of these buses go it will be nice to have to prevent any of the problems typically associated with using too light a wire for too long a run on a DCC system. According the Oregon inspection standards (changing hats for a minute), which I believe are based on the 2005 NEC, 14 ga. wire is fine for 15 amp branch circuits, 12 ga. is fine for 20 amp branch circuits, and 10 ga. is for either 25 or 30 amp (can't remember) branch circuits, assuming solid copper wire. The difference is that my oven is not receiving signals through the branch circuit, just power. There's no issues about strength of signal, just about possibly overheating wire. Adam
^ This is true Steamdonkey. It is Article 310 in the 2005 NEC. Table 310.16 gives rated ampacity(ies), but those ampacities change based not only temperature rating but insulation types, etc. There is a table for not more than 3 current carrying conductors in a raceway, and one for a single conductor in free air. Both tables are temperature and insulation type based. Table 310.13 lists all the different insulation types and associated temperature ratings. However, for the purposes of model railroading, the voltages and VA seen over the typical 12 and 14 AWG bus wire we use won't even come close to hitting the max power that can be carried in those conductors based on their NEC ratings.
