I am getting back into the hobby after being away from it for over 25 years, I am modeling HO scale and DCC. The electrical part of the hobby is not my strong suit, my question is, my layout will be a sort of DogBone set up, I intend to run two main lines with one of the main lines using turnouts to service different business. Do I need to run separate buss wiring for each main line? Also, if I connect both main lines will a crossover will that make the wiring more difficult. Sorry if I am leaving out information that may be needed to answer my questions as I am a novice. Thank you for any help in this matter.
A single bus is all you need. As for crossovers adding complexity, it kind of depends on your track plan and their placement. Simply crossing over between mains A & B as they run parallel to each other generally isn't a big deal. If in your dogbone you bring both mains back in close effectively making a stretch of 4 track main and then you added a crossover from mainline A and the returning mainline A, then you will have created a return loop situation, which will require more effort/complexity.
Mike
woodmanDo I need to run separate buss wiring for each main line?
No.
woodman if I connect both main lines will a crossover will that make the wiring more difficult.
Unless...
If you want to do occupancy detection and/or signalling, then you need to do a little more planning.
If you are careful about keeping track of which is the red rail and which is the black rail, you won't have problems. If your crossover (or any other track) would require you to connect two rails of the opposite color, you have created a reversing section which requires special handling.
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woodmanAlso, if I connect both main lines will a crossover will that make the wiring more difficult.
If it's a dogbone and you connect the mainlines with a crossover, you have created a reversing path and you will need to wire it appropriately. Only slightly more complicated; and auto-reversers make it easy.
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As Byron said, a dogbone with crossovers creates reverse loops. With DCC it's not a big deal because you can automate the polarity flipping so all you need to do it drive the train. Where you isolate the reversing sections is the real question. What works best somewhat depends on your plan.
In my case - my whole plan is 'double track' with the two mains connected by a loop at each end. Those loops are also part of hidden staging What I plan to do then is to make the loops at the ends the reversing section as each is far longer than the longest train I plan to run and I can actually gap it such that a train entering staging will not be crossing the gaps at the same time as another train leaving staging. By making the loops the reverse sections, I can put as many crossovers in the main as I want and not have to worry about anything. As such, teh bus wiring is also pretty simple - one bus run along the two tracks, and both get wired the same that is the rail closest to the wall gets a red feeder, the othe rail of that track gets a white feeder. On the other main, repeat the rail closest to the wall (and the other track) gets the red feeder, the rail closest to the aisle gets the white feeder.
Other needs may dictate that a section of the main be used as the reversing section. All depends on how your plan is designed and how you plan on running it.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I would also suggest that you use #12 wire for your busses. You can buy the stuff (I'd recommend solid) in 500 foot rolls, or smaller ones, depending on layout size and complexity. Big box stores stock several different sizes of rolls.
My last few endeavors have been hand laid rail and each one got a feeder - no rail joiners used. I don't think you would be disappointed with performance feeding each rail no matter what you use in the way of track and can worry about using rail joiners for alignment and forget about soldering them for continuity.
I generally agree, but...
How big is your layout?
What other trackage do you have besides the dogbone?
I use #18 wire for my layout's track bus. I've got a good-sized room layout, but it's not a club layout or even a basement empire. Yes, #12 wire is "better" but most home layouts would never notice the difference.
I have broken my layout into power districts, each protected by a circuit breaker or auto-reverser. This makes it easier to troubleshoot problems, and lets parts of the layout keep running if one shuts down for a short. In your case, you might want to break up the loops as separate districts, or perhaps create an "eastern" and "western" division. Power divisions, however you define them, require isolated tracks and separate buses for each division. You don't have to add the breakers right away, but if you're thinking of this it's much easier to wire them this way from the beginning.
It takes an iron man to play with a toy iron horse.
Ive used #14 stranded for the buss and #22 solid for the feeders.
I would not want to kiss the wiring at all! (Gross)
Buss is a kiss. (Or a brand name of fuses)
Bus is a vehicle in this case a wire to move electicity.
ROAR
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I have a ''folded dogbone''? 14X12X14. At first the whole thing was wired with 22ga feeders just pigtailed together.Ran fine, In order to clean it up, I ran a 12ga bus.
I used 12ga because thats what I had on hand. I f I was to do it over, I would buy some 14ga, way easyer to work with
BroadwayLion I would not want to kiss the wiring at all! (Gross) Buss is a kiss. (Or a brand name of fuses) Bus is a vehicle in this case a wire to move electicity. ROAR
I agree in principle, but have long since given up attempting to pee into that windstorm. I get the worst of it if'n I do.
To the OP, I have only ever used 14 gauge house wire, the kind that goes to the many of the wall outlets everywhere across the continent. I am sure 16 gauge would work for all but the largest and most demanding layouts where something like 15+ amps are routinely coursing through the bus. 12 gauge is too heavy; use it only if you can get it for a song or have some lying around, or know that you will often have 20 amp loads drawn.
Does it help (or at least not hinder) to use smaller wires farther out on the bus? I hesitate to use the word dendritic, but that's what I'm talking about.
For example, using #12 wire directly connected to the controller for 20 feet or so, then attaching #16 branches about 10 feet or so, then #18 fingers maybe 3 or 4 feet, then #22 feeders to the tracks? Or something like that? Feeders could be connected anywhere along the bus tree.
Robert
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Two things determine what size wire to use (well three if you are trying to do ti on the cheap - but be careful about cheaping out too much). Length of the run, and how many trains will be running (ie, the load, current) in the section powered by that length of wire.
Your goal should be to minimize the length of the wire run, which allows you to use thinner (and cheaper) wire to accomplish the same goal. There are various web pages that have calculators for voltage drop over a length of a wire of a given size. Remember that for electricity you need a complete circuit, so to reach a point 20 feet from the power source, the current must flow through 40 feet of wire. You want to keep the voltage drop to half a volt or less for best operation. This is where the second item, number of trains running at the end of that wire, comes in, The voltage drop is proportional to the load. It does not matter if the booster puts out 5 amps, if there's never more than one loco at a time running on a particular segment of the layout. To a point - you do have to make sure there is not too much drop so that the circuit breaker does not cut off power when doing the quarter test - exactly what it sounds like, set a quarter (or equivalent if not in the US) on the rails - do not push down, just set it across th rails. If the circuit breaker does not trip, you have insufficient wiring, either not enough feeders or too small a wire size for the bus.
Say you have a wall 30 feet long where you have track. If you place the booster at one end, you end up with a bus length of 30 feet. If you place the booster in the middle and run bus lines to each side, they are each only 15 feet - huge improvement.
My previous layout was 10x13 around the walls of a room. I onlyhad a single booster, but by running bus lines out to either side they ended up being about 20 feet long each. I used #14 wire with no problem. Any longer, or if I was going to have more trains (the layout only handled 2-3 train at a time, tops), I would have used #12.
Use stranded for the bus. It's easier to snake around the underside of the layout and through holes drilled in the cross braces and so forth. $12 or #14 solid is much more difficult to work with.
I always used solid for busses because I found it easier to attach the taps to in those not so accessible places. Used a stripper to cut the insulation around in 2 places then a knife to strip off a slice between with no worries of snagging and cutting a strand or more because of a bad access angle. I always mounted my spools on a shaft and the wire pulled pretty easy through "thought out" holes. I also found solid to be much less likely to retain the coiling tendency and pulled straight between supports and stayed that way. The joints for feeders also use significantly less solder.
The majority of stuff that got run on the layouts I wired was older brass with high current motors and 4% grades with long distances from the power supplies so voltage drop was a concern. Found no reason to use more than one size buss wire and one size feeder, and 12 won out as the buss size. Because the club dictates said each rail got fed individually there was no way to shorten busses as one ran under each rail.
Most of my wiring was on club layouts so distance was definitely a concern, but if wiring one at home I'd do the same thing because I'd have the materials on hand because of my (main) trade.
YMMV
No point in using different sizes along the length of the bus, that just makes things more complicated. The connections between wires are the most likely place for a problem. An exception might be for detection sub-busses. #12 for the whole thing, then at each detection block, all feeders connected to a #14 bus. The detector goes in the jumper between the #12 main bus and the #14 sub bus. It sounds complicated but it've very easy to follow and understand even after the fact. Besides different colors, the different sizes of the wires is an added reinforcement of what goes where. And since the detection section is going to be realtively small, there's no issue with voltage drop just because the wire is a size smaller than the main bus.
I use the Ideal Stripmaster or similar stripper to take out my chunks of insulation in the middle - I have yet to have any issue with nicking a strand of stranded wire. All my connections are soldered, I just don;t like crimp-only sorts of things.
I do use solid for feeders, it's easier to place and solder to the rail. Twisted around the bare section of bus wire, it stays put until soldered.
Atchee Found no reason to use more than one size buss wire and one size feeder, and 12 won out as the buss size. Because the club dictates said each rail got fed individually there was no way to shorten busses as one ran under each rail.
Found no reason to use more than one size buss wire and one size feeder, and 12 won out as the buss size. Because the club dictates said each rail got fed individually there was no way to shorten busses as one ran under each rail.
The reason I asked about different size bus wires was my concern about the lengths of the feeders.
All things considered, I'd prefer to use #12 solid bus and #22 solid feeders. But how long can the feeders be? 2 feet? 3 feet? 8 feet? I've seen all kinds of numbers.
The easiest solution would be to wire my new layout similar to how our club wires theirs: run the bus directly under the rails with a lot of feeders 6 or 8 inches long or so. But my layout has two decks, and in most places has two mainlines running along both the front edge and the rear. Can I run a single bus down the center and feed both decks and both mainlines? To do so the feeders would need to be in the 3' or 4' long range. Maybe more. What about the helix? Will I have to coil the #12 main bus along the ramp? Or can I terminate the bus on one side of the helix and use #22 feeders? In that case they might have to be 5' or 6' long. Maybe a little longer.
My specific question: how long can #22 solid wire feeders be. Nominal spacing throughout would be about 6' (two flextrack sections soldered together). Maybe 10 or 15 engines (max) running at any one time. Maybe a lighted passenger train or two. I don't have sound, but some of my friends might.
Thanks.
For 2 desks you'd want at least one bus run per deck. For the helix, You'd run 2 or 4 vertical busses to tap off a feeder to each layer. 2 bus runs would give 2 pairs of feeders for each turn of th ehelix, each halfway around. Which should be enough unless you are building a 40" radius helix, or a large oval helix, in which caee you might want more feeders.
Feeders should be short. Under a foot is fine, you don't want to start getting them much longer.
ROBERT PETRICKMy specific question: how long can #22 solid wire feeders be.
Take a look at "The Great Feeder Experiment" here:
http://www.wiringfordcc.com/track_2.htm#a14
carl425 ROBERT PETRICK My specific question: how long can #22 solid wire feeders be. http://www.wiringfordcc.com/track_2.htm#a14
ROBERT PETRICK My specific question: how long can #22 solid wire feeders be.
ROBERT PETRICKThere appears to be two prime sources for DCC Info: WiringForDCC and DCCWiki . . . the problem is they have very different information.
I think the reason they have different answers is they are answering different questions. I believe DCCWiki's recommendation is based on a calculation to determine what size wire will keep the voltage drop to a specified minimum. WiringforDCC's info is from an actual test to determine what size feeder you need to guarantee your breaker will trip in the event of a short. IMO, the "quarter test" is the more important standard to meet.
carl425 WiringforDCC's info is from an actual test to determine what size feeder you need to guarantee your breaker will trip in the event of a short. IMO, the "quarter test" is the more important standard to meet.
WiringforDCC's info is from an actual test to determine what size feeder you need to guarantee your breaker will trip in the event of a short. IMO, the "quarter test" is the more important standard to meet.
Okay, good. A straightforward clear answer. I like that.
I don't mind putting more effort up front if it avoids problems later.
Thanks,
Ponder this. Many people post having issues with sound dropouts, and it's always blamed on dirty track, or dirty wheels.
On the other hand, I've not had these problems on either of two layouts I've built since going DCC (not counting a simple table top loop I built to test the DCC). I have feeders to each section, and either a #12 or #14 bus. My feeders (HO) are #20. I solder every other piece of flex track together, but there are still feeders to each section. In HO most flex is 36" long. SO i have <regular joiners>----track section----<soldered joiners>-----track section----<regular joiners> and so on. No power problems, not issues at all. Can you get away with less? Probably. But it's not any more difficult to add extra, and unless you plan on ripping up this layout in a couple of years, go for long term reliability. The last thing you want is the slide fit rail joiners being the only source fo power for a track section. It WILL become erractic as the joiners work loose over time. I don't believe in soldering ALL rail joiners, unless you have a very stable temperature and humidity throughout the year to minimize any expansion and contraction. That's why I do every other. Starting on curves - I solder two pieces together and form the curve with that. If you have a set of joiners solderd, you MIGHT get away with one set of feeders for both track sections, but definitely not if the joint is not soldered.
It's easier to get it right and robust enough from the start than trying to go back later and add additional feeders because a section starts acting up a year from now once there is scenery in place and all that.
rrinker Ponder this. Many people post having issues with sound dropouts, and it's always blamed on dirty track, or dirty wheels. On the other hand, I've not had these problems on either of two layouts I've built since going DCC (not counting a simple table top loop I built to test the DCC). I have feeders to each section, and either a #12 or #14 bus. My feeders (HO) are #20. I solder every other piece of flex track together, but there are still feeders to each section. In HO most flex is 36" long. SO i have <regular joiners>----track section----<soldered joiners>-----track section----<regular joiners> and so on. No power problems, not issues at all. Can you get away with less? Probably. But it's not any more difficult to add extra, and unless you plan on ripping up this layout in a couple of years, go for long term reliability. The last thing you want is the slide fit rail joiners being the only source fo power for a track section. It WILL become erractic as the joiners work loose over time. I don't believe in soldering ALL rail joiners, unless you have a very stable temperature and humidity throughout the year to minimize any expansion and contraction. That's why I do every other. Starting on curves - I solder two pieces together and form the curve with that. If you have a set of joiners solderd, you MIGHT get away with one set of feeders for both track sections, but definitely not if the joint is not soldered. It's easier to get it right and robust enough from the start than trying to go back later and add additional feeders because a section starts acting up a year from now once there is scenery in place and all that. --Randy
Hey Randy-
I agree with your last paragraph. With additional info from Carl. I don't want the first indication of a problem to be melting plastic and frying decoders caused by an undetected short.
My plan was/is to connect two sections (N scale, 36" flextrack) with a soldered joint and include a #22 feeder into the joint. That way the feeder is in the middle of a 6' "butterfly" arrangement . . . <regular joiners>----track section----<soldered joiners>-----track section----<regular joiners> . . .
Temperature variation is not an issue. Neither is humidity. I live in the high desert of Wyoming, and relative humidity varies from a low of 12% to a high of 14%. Static electricity and dry eyeballs are the main concerns.
Like Carl said, the quarter test is fairly critical. It's a good indicator of sufficient wiring. Remember you do not press the quarter down, just lay it across the rails. If the breaker trips - everything is good and there is little likelyhood you will fry or melt anything from a derailment. Test not just at feeder locations but at the furthest spot from each feeder.
How important is this? Well, I recommend that you use downstream circuit breakers to power various sections since N scale pretty much never would need 5 amps in one area of the layout. But let's say the 5 amp booster is connected right to the rails. If the resistence of the bus/feeder/rail is low enough, a quarter across the rails will draw more than 5 amps, tripping the breaker. But if the bus was too small, or there weren't enough feeders, and there is just 3 ohms of resistence in the wiring (that's not much). Assume a nominal 12V track voltage for N scale. Ohm's law says that's 12 volts/3 ohms, or 4 amps of current. The booster cannot tell the difference between 4 amps being drawn to run a dozen locos, or 4 amps being drawn because there is a truck sideways bridging the rails (our quarter), and the breaker does not trip. 4 amps at 12 volts is 48 watts of heat. Pretty close to 50 watts. MORE than enough to melt plastic, as my poor melted calculator that my oldest son 'hid' in a bedside lamp when he was little will attest. That was only a 40 watt bulb, and by the time I noticed the calculator sitting on top of it, it was destroyed.
Pass the quarter test though, and you can be fairly certain that you will not have any melted sideframes or burned loco shells. That does not mean you can leave everything powered up in a short condition and go eat dinner - most systems periodically turnt he power back on to test if the short is still there and even if it trips again right away, the combined retries can get things warm enough to melt - even when the short IS detected.