Currently I have a thin gauge wire feeding the track. (About 168 feet of track.) And now the locos are starting to sputter in places they shouldn't.
I have 16 gauge black & white wire available. This would go from the NCE SB5 5 amp booster directly to all 3 main lines. Is this appropriate or should I go with thicker guage?
We usually run 3-5 loco's per main. Here is a video of my layout. As you can see the wire I'm using for the switches is the same wire I'm using to feed the track. Thanks for your input.
https://www.youtube.com/watch?v=cNLKBHhKpRA
If your layout was running OK in the begining with your "thin gage wire", that would suggest dirty track at this point, not inadequate wire. You don't say what wire you currently have for your buss but if it is less than the 16 gage, your buss is very undersized. I would suggest at least 14 ga for buss, 12 is better.
A weak (undersized buss) combined with dirty track means that your loco's are not getting enough power.
Paul D
N scale Washita and Santa Fe RailroadSouthern Oklahoma circa late 70's
You should also have multiple feeder wires to the track, as the rail itself is not a very good conductor. You should also solder your track together, with some spacing left for heat/cold expansion. Some advocate feeders every 12 inches - an overkill in my opinion. I have put them at every 24 inches on my layout.
Simon
PED If your layout was running OK in the begining with your "thin gage wire", that would suggest dirty track at this point, not inadequate wire. You don't say what wire you currently have for your buss but if it is less than the 16 gage, your buss is very undersized. I would suggest at least 14 ga for buss, 12 is better. A weak (undersized buss) combined with dirty track means that your loco's are not getting enough power.
The NCE site recommends 12 gauge for larger layouts.
snjroy The NCE site recommends 12 gauge for larger layouts.
Hi there. I am not aware of NMRA standards with respect to feeders. This site contains some information:
https://dccwiki.com/Wire_Sizes_and_Spacing
It suggests between 18 and 20 inches (if I read the table correctly).
snjroyIt suggests between 18 and 20 inches (if I read the table correctly)
He suggests 18-20 gauge wire for feeders. Not 18 to 20 inch spacing.
For HO spacing between feeders, he recommends 3 to 6 feet.
I have the right to remain silent. By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.
My layout is not that much different in size than yours. I run 14 gauge wire as a main bus and run #22 gauge solid wire feeders from the bus to the rails. I find 22 gauge solid wire is very easy to solder to the tracks, easy to hide and very durible if you don't flex it much. The 14 gauge strand wire is very flexible to work with and carries more than enough power to all the tracks. I solder a pair of feeders to every section of track, so there is a feeder no farther apart than 5' with 36" flex track. If there are smaller sections of track, they either get a feeder soldered to them or they are soldered to a larger section. Try to limit the distance to 36" if you can. If you solder flex track sections together, I put a feeder every 36".
This provides me with more than enough power to run at least 11 sound locomotives (3 Bowser F7's, 5 Bachmann GP-40's and 3 Athearn SD70MAC's) from my NCE Powercab and 5 amp Smart Booster. There is also a Bachmann EM1 steam locomotive and an Athearn Big Boy idling on a siding as well.
All this work is for naught if you have dirty track.
Firstly, joiners are notoriously poor at providing anything more than mechanical alignment at the joints; they provide generally unreliable continuity electrically.
Secondly, the above means that many/most of your joiners should be soldered. If done well, the solder greatly improves continuity, not to mention strengthening the joints placed necessarily along curves, especially sharp curves where the strain is greatest.
Thirdly, the broader the cross section of a given wire, the better it is to counter voltage losses over distance. The nickel-silver rails are rather modest in their ability to transmit voltage and current, so we use a generous gauge of wire to do that. Generally, nothing less than 14 gauge, thicker when the layout gets rather large with long runs of rails.
Feeders should be near 20-22 gauge for ease of use, but also necessarily short due to their small cross-section. So as not to negate the advantage of the broad wire bus mentioned previously, use feeders often. My own practice is to solder a feeder into every second joiner. That way, the power loss over distance is never greater than 36" in either direction, and you can minimize your work and use of materials while maximizing the intended salutary effect of high voltage.
Some people advocate soldering a feeder to every contiguous length of track, be it 12", 24" or 36". I routinely feed 6" of rails with one feeder pair in the configuration I just described: one pair of feeders into every second joiner pair, and the logic is every bit as good...and successful.
for general info. all info is for solid copper wire . 20 gauge max amps 6, for 16 gauge max amps 10., 14 gauge max amps 20, 12 gauge max amps 25, now all the max apms should be reduced to 75 % for safety factor. as for restance (not a factor in most modeling apps.) 20 gauge 10.4 ohms per 1000 ft, 16 gauge 3.96 per 1m ft, 14 gauge 2.54 per 1m ft, 12 gauge 1.65 per 1m ft.
At model railroad voltages, max amps doesn't really come into it, but the resistence and corresponding voltage drop does. Losing 8.3% from 120V AV means the device at the other end of the wire gets 110V AC and operates just fine. Dropping 8.3% from a 16V booster output means the train at the end of the line has a 1.3V drop - that is quite a noticeable speed difference. Also, I think your numbers are off there. #20 can't be 10.4 phms per 1000ft and then #16 also 10.4 ohms but per meter - that puts #16, the thicker wire, at more than 300x the resistance. Other charts has #20 at 10.15 ohms per 1K foot, #16 at 4.016 ohms per 1K foot, #18 at 6.385 ohms per 1K foot, and #12 at 1.588 ohms per 1K foot
Remember a complete circuit is out and back, so if the end of the wire connects to the track 160 feet away from the booster, the electricity travels 320 feet. Times the resistance per foot for the size wire, times the current draw by the loco, is your voltage drop. You want to keep that to .5V or less.
So for #16, 320 feet x .004016 ohms per foot is 1.285 ohms.With a single loco, drawing 1/2 amp, that's a .643V drop. Stick a bunch of locos down there drawing a full amp, and the voltage drops 1.285V - a very noticeable speed decrease.
Even if the booster were in the middle of the 160 foot run, so the furthest out to each side was 80 feet, 160 feet of wire per side, you simply halve the numbers above, and it's STILL too much drop if there are several locos operating. The solution is either #12 wire, or add boosters simply to decrease the bus length. Just having 2 boosters instead of one, evenly spaces, along a 150 foot run, you end up with 4 segments, each 40 feet long. Now in our 1 amp multiple loco case, we have a maximum drop of just .321V, acceptable, but because with multiple boosters it's unlikely all the locos will be at the end of one booster's power bus and the other one will be sitting there with no load, the actual drop will probbaly be less. Winner winner, chicken dinner.
Remember - it might not be the numberof trains you are trying to run that determines how many boosters you need. a Physically huge layout with relatively few trains may require extra boosters just to keep the bus run and the voltage drop under control. There is practically no current on the booster bus that links the DCC signal to each booster, as long as the voltage remains above the booster's threshold it will be properly amplified and fed to the rails.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
robkozCurrently I have a thin gauge wire feeding the track. (About 168 feet of track.)
Not sure whether you have a triple main with 168' of track for each or whether 168' is the total (roughly 55' circles). In any event, if you follow the bus & feeder guidelines you should be quite ok, as long as you avoid weak links as folks point out, such as (potentially loose or corroded) rail joiners for continuity.
Regarding bus length, I relied on "The DCC Guide" booklet that advises to stay within a 1/2 volt drop. Their table indicates max "bus" length (at 5 amps) of 25' for 16AWG, 40' for 14AWG and 63' for 12AWG. They recommend feeders of 20-22AWG but do not specify the length. Your shelf arrangement means feeders can be relatively short.
I have a modest layout that only needed 16AWG (I used stranded) bus, and I used (2' max) 22AWG solid feeders, max 6' separation. I also provided power to each piece of track. Pretty consistent with all the suggestions above. Taking the trouble to follow the guidelines is worth it and not much extra work.
BTW, are you familiar with the "quarter test"? Suggest you try it out now to see if your breaker will trip at all parts of the layout as currently wired (just for info on your problems) as well as testing your modifications to ensure performance. Not saying at all not to upgrade the wiring, even if you pass the quarter test everywhere now.
https://dccwiki.com/Quarter_Test
Paul
Modeling HO with a transition era UP bent
1m simply means 1000. shees and i corrected the ohms.
12 AWG braided wire for the bus20 AWG solid core for the feeders
Got it!
Do you recommend these to feed the tracks from the bus?
https://www.ebay.com/itm/NEW-Acculite-VAMPIRE-II-DCC-Power-Bus-Wiring-Connector-Single-Bob-The-Train-Guy/401525468333?hash=item5d7cc86cad:g:StMAAOSwcLxYDkNX:sc:USPSFirstClass!11790!US!-1:rk:1:pf:0
robkoz 12 AWG braided wire for the bus20 AWG solid core for the feeders Got it! Do you recommend these to feed the tracks from the bus? https://www.ebay.com/itm/NEW-Acculite-VAMPIRE-II-DCC-Power-Bus-Wiring-Connector-Single-Bob-The-Train-Guy/401525468333?hash=item5d7cc86cad:g:StMAAOSwcLxYDkNX:sc:USPSFirstClass!11790!US!-1:rk:1:pf:0
I would NOT recommend these. Splice into the main bus with a solder connectior or a T-tap style suit case connector. I personally use the T-tap suit case connectors because they allow you to insert a track feeder with a spade connector into the main bus wire without solder or cutting the bus wire. Never ... NEVER cut the main bus unless it is absolutely necessary, like installing a circuit breaker. On top of this, each connector cost $1.75 where the T-Taps are about $.04 each in bulk. I get mine in quantities of 300, which is 150 connections (+ & - ).
Look at this article to see the connectors I am talking about. The nice part is you can unplug the feeder to check for shorts or other problems without cutting any wires, and it's easy to plug a 20 gauge solid wire into the 14 gauge bus without cutting the main bus.
http://www.dccguy.com/?tag=tortoise
B. BryceNever ... NEVER cut the main bus or insert any fittings that may screw up the DCC signals.
I guess the module guys don't know that. But I'm not thrilled with the Vampire either.
There are wire strippers that will separate the insulation, without cutting the wire.https://tinyurl.com/y8ehsv2n
If you are starting from scratch, you can figure out where the feeders need to be and solder them above the layout. I also asked about suitcase connectors some time ago, because in the motorcycle world, they are considered a fail waiting to happen. Unlike motorcycles, layouts don't bounce around and vibrate and virtually no one had anything bad to say about 3M suitcase connectors.
There are Chinese knockoffs, that some didn't like. Suitcase connectors also come in different sizes, so pay attention to what you are ordering.
You could also run a sub bus to a barrier strip or a bus bar. A bus bar is hot, because it is all metal or brass. A barrier strip has 4, 6, 8, 10 or 12 pairs of terminals. If you hold it length wise, only the top terminal is connected to the bottom. There is not connection to the terminals on either side. You can buy or make jumpers so you can connect adjacent terminals, so you could turn a 12 pair into 6+ and 6- terminals or whatever you want to call the different DCC polarities. You can run your feeders out from the terminal strip.
Henry
COB Potomac & Northern
Shenandoah Valley
I agree with everything Henry has said. My preference is still the T-Tap connectors because they are fast, easy and you don't have to try and solder over your head. The connector bars are far better connections than the Vampire, but still cost a boatload more than the suitcase connectors. Also, I can space the T-Taps on the main bus where I don't need more than a 6"-9" feeder. You may find that you will need much longer feeders for them all to reach the block connector. I agree that on motorcycles, they are a problem waiting to happen, but I also agree a model railroad doesn't bounce around, vibrate and is not normally driven in all kinds of weather and temperatures. If your T-Taps are corroding, I would hate to see what is happening to the rest of your layout! I have never once had an issue with any of my connectors and have plugged and unplugged them several times to do different things. I also did get a small batch of the off brand ones, and they were almost impossible to plug and unplug the spade into the T-Tap because of sloppy plating on the spade. Always go with the 3M connectors. The look the same, but I found they are not, because they work. Also, I use a blue T-tap on the 14 gauge main bus and a red spade on the 20 gauge (22 gauge in my case) feeders. If you wish to plug a 16 gauge wire into the main for an accessory, simply use a blue spade connector.
PS, if you are selling a product, you will always say it works the best. I don't sell either of these, I just use them.
Just not a fan of suitcase connectors - plus the standard sizes don't do #12 to #20 which is what my feeders are. I have Ideal brand strippers similar to what Henry posted, except it has specific holes in the cutting die side for different wire sizes. This cleanly strips back the insulation in the middle of the bus without cutting the wires, and I just wrap the stripped end of the feeder around the bare spot on the bus. Then I go around and hit the joints with a larger (150 watt) soldering gun. Offset the connections - I've never had a problem with adjacent joints shorting because even if you squeeze the two bus wires together, the connections don't touch, but liquid electrical tape will insulate it if you are paranoid.
If that is what works best for you, then keep doing it. I personally like the suitcase connectors. If you need to use them with 12 and 20 gauge, use the yellow connector on the 12 gauge and the red spade on the feeder. That will work fine. All I have to do is select where I want to tap into the bus, squeeze a T-Tap onto the bus wire, plug in the feeder and I am done. No solder, no strippers, no heat, no liquid tape, just squeeze the T-tap, plug in the feeder and I am finished. But again, if you prefer the other method, by all means, stay with it.
B. Bryce If that is what works best for you, then keep doing it. I personally like the suitcase connectors. If you need to use them with 12 and 20 gauge, use the yellow connector on the 12 gauge and the red spade on the feeder. That will work fine. All I have to do is select where I want to tap into the bus, squeeze a T-Tap onto the bus wire, plug in the feeder and I am done. No solder, no strippers, no heat, no liquid tape, just squeeze the T-tap, plug in the feeder and I am finished. But again, if you prefer the other method, by all means, stay with it.
Before you spend considerable time and effort feeding every rail or nearly every one, consider your particular layout and construction materials and methods. Remember that except for locations that will be inaccessible, you can always add feeders if over time the layout develops a need for more. It's easy to drill a small hole next to a rail, drop a feeder and attach it to the bus and rail. You can also solder joiners later if they prove to loosen or otherwise lose electrical conductivity (or add jumpers between rail ends). Basically, I installed feeders to sections of track without power because of rail gaps at frogs of certain power-routing turnouts. Probably the longest total run of track without a feeder is about 12'.
I use Walthers/Shinohara Code 83 flex and turnouts. I also use their track joiners which are a much tighter fit than the typical Atlas joiners. I also treated each end of rail with No-Ox before joining. Another factor is the layout environment. Is it subject to significant swings in temperature and humidity? Although my layout room has a controlled environment, I painted all the wood benchwork, the plywood and Homasote sheets that comprise the bench top (all sides and edges) and the Homabed roadbed to minimize moisture absorption.
The layout voltage is uniform throughout. I cannot claim 20 years' successful experience, but the layout is fully operational for over 6 years without a power problem. Admittedly, the track is not yet ballasted or painted. So far so good; I shall see how it performs over a longer time. However, as I said before, I can always add feeders and/or solder joiners.
Dante
robkoz B. Bryce If that is what works best for you, then keep doing it. I personally like the suitcase connectors. If you need to use them with 12 and 20 gauge, use the yellow connector on the 12 gauge and the red spade on the feeder. That will work fine. All I have to do is select where I want to tap into the bus, squeeze a T-Tap onto the bus wire, plug in the feeder and I am done. No solder, no strippers, no heat, no liquid tape, just squeeze the T-tap, plug in the feeder and I am finished. But again, if you prefer the other method, by all means, stay with it. Where do you get those yellow connectors & all the spades for the 12 guage wire? And I don't have to strip the insulation for a good connection? Seems too good to be true. But then again this is my first big layout so I'll believe the experienced ones anyday.
12 gauge T-Tap: https://www.delcity.net/catalogdetails?item=908085
Other T-Tap: https://www.delcity.net/store/Quick-Splice-&-Tap-Connectors/p_901562
Spade Connectors: https://www.delcity.net/store/Push!On-Terminals/p_801898
robkoz snjroy The NCE site recommends 12 gauge for larger layouts. Thanks. I read your previous post and I'll have to install feeders. Are there NMRA standards for this?
There are no "NMRA standards" published regarding track bus and feeder specs, because that isn't what standards are about. Even their recommended practices don't really get into detail on this. Many books will not really talk about it either, other than suggesting a minimum recommended gauge. Most charts for current capacity of copper wire are also only listing the maximum current which will cause a rise in temperature to 30C, with a 60Hz sine wave. DCC isn't a sine wave and it is in the 8 to 10 kHz range as well.
A good rule is to try to keep voltage drop to 5% or less. Heavier wire is always better.
robkozI don't have to strip the insulation for a good connection?
You do have to strip the end of the feeder that goes into the tap. (at least according to the demo I watched).
https://www.youtube.com/watch?v=ikZZBmvFEho
carl425 robkoz I don't have to strip the insulation for a good connection? You do have to strip the end of the feeder that goes into the tap. (at least according to the demo I watched). https://www.youtube.com/watch?v=ikZZBmvFEho
robkoz I don't have to strip the insulation for a good connection?
The video is exactly how you will do it. The T-Tap goes on what ever size wire you use for the bus, in their case they are using 14 gauge wire. The spade connection she crimped onto the end of the other wire will be your 20 gauge feeder, so you will use a red spade going into the yellow T-Tap. Any size can be combined with any size. Just make sure the T-tap is sized for whatever size wire you are using for the main bus and the Spade plug which is being inserted into the T-tap is sized for your feeder wires, which are soldered to yout track.
14 gage bus, 18 gage feeders for me, and I have the bus and the feeders with spade connectors to Radio Shack barrier strips. Unfortunately, Radio Shack is basically defunct. But no matter which method you use, invest in a label printer from Staples and label the location of each feeder underneath the layout. When it starts to look like spaghetti under there, you will know why. A quick pass with shellack, varnish, polyurethane, whatever clear liquid of this nature, and that label is going to stay there.
PS: 16 gage feeders will probably be better for a larger layout. check out Alan Gartner's site "Wiring for DCC" for lots of info.
Bear "It's all about having fun."
Great stuff guys thanks! Now questions:
1. What color wires do you use for the bus and the track feeds? Black and white?
2. As you can see from the video above it's a shelf/elevated layout. What's the best way to keep the bus secured to the bottom of the plywood?
Thanks
How'd you know I used white and black? The trains don't care what color you use, as long as you are consistent, and don't use a piece of black wire when you needed white, but ran out. It doesn't pay to switch colors midstream either.
I used a cable staple gun, the staples look like little croquet hoops, but there are also plastic cable clamps.
I use red and white because it's an available set of colors plus I found some very nice #20 solid wire that came on spools looosely twisted (so easy to make two seperate pieces) that was also red and white. It's marked as alrm wire, guess they use this to runt he sensors for wired alarm systems. Anyway, it has made good feeder wire for two layouts now and while what I have left is probably not enough for the size of my next layout, it's still available.
By following a conventon of Red to the Rear (ie, away from the fascia/aisle side), hooking things up became a matter of attaching all the red wires hanging down to the red bus wire, and white to white.
It doesn;t matter what color, as long as you use some color scheme and stick to it. I was originally going to use red and black for the bus wires, but it was pointed out that in the less than ideal light under the layout, red and black look a lot alike. So red and white it was.