Hello everyone,
I am ready to start wiring my new layout. I want to use a power bus wire to connect smaller feeder wires around the track. Since my older layouts were very primitive (just one set of feeder wires) I am unsure what size wire to use. What is a good size wire and where can I find wire to use for a power bus? I have the atlas rolls of 20 gauge wire on hand.. will this be sufficient? Thanks in advance , Nick
How big is your layout, how far does the wire have to travel.?
Will it work? What do you mean by work? Will the wire heat up and start a fire? : No not likely.Will the train move? : Yes the train will move. Is that what you want? : NO IT IS NOT!
20 ga will work, but what you loose is the slower speeds, since you would have to use a higher voltage to force the same amount of current through the conductor.
14 ga is supposed to be good for DCC, and thus it is also good for DC. I am using 12 ga on my DC layout. LION would use 18 ga for the feeders, and 14 - 12 ga for the bus, but then the LION has 1000' of tracks!
LION gets his wire from the powerhouse. But then I do not suppose many model railroaders have a powerhouse in their back yard, with miles and miles of scrap wire of every description. I guess you'll just have to go to your favorite home improvement store and pick up a coil of wire. The LION prefers stranded wire for the bus as it is easier to work with. 18 ga for the track feeders. You could use suitcase connectors, but my use of them did not turn out as well as I had hoped. I should have gone with the bigger suitcase connector for the bigger wire, but my home store did not have any.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
My layout is smaller than The Broadway Lion's. I use 18-gauge wire. i have no runs over 20 feet, and most are considerably shorter than that. I use DCC, plenty of feeders, and this works fine for me.
The "standard" recommendation is 14-gauge, and many use 12. 12-gauge is standard wire for a 20-amp household circuit. It will work great, but for me, that's overkill for anything less than a club-sized layout.
Buy your wire online, at places like Mouser or All Electronics. I have a local electronics place near me, and I often go there, too. Avoid Radio $hack. They sell small rolls of wire at seriously inflated prices.
It takes an iron man to play with a toy iron horse.
That Atlas 20 gauge wire would be fine for the feeder wires, but I would recommend standard household 14 gauge wire for the bus wires. I drop feeder wires about every 6 to 7 feet. However, I should (but don't) wire feeders on the end of every leg of every turnout.
Rich
Alton Junction
only
nick45326 Hello everyone, I am ready to start wiring my new layout. I want to use a power bus wire to connect smaller feeder wires around the track. Since my older layouts were very primitive (just one set of feeder wires) I am unsure what size wire to use. What is a good size wire and where can I find wire to use for a power bus? I have the atlas rolls of 20 gauge wire on hand.. will this be sufficient? Thanks in advance , Nick
Way back in the 1950s I was an electronics tech an for what it's worth 14 gauge wire should be plenty big for the normal home layout. Now, there is something else. I was taught that the electrons travel on the surface of the wire only and that is why heavy current draw is feed with stranded wire. This may not even apply to our application, but I did use stranded wire for my buss.
Have a good day
Lee
yankee flyer Way back in the 1950s I was an electronics tech an for what it's worth 14 gauge wire should be plenty big for the normal home layout. Now, there is something else. I was taught that the electrons travel on the surface of the wire only and that is why heavy current draw is feed with stranded wire. This may not even apply to our application, but I did use stranded wire for my buss.
Interesting.
I use solid 14 gauge wire for the bus, but stranded wire for the feeders.
BroadwayLion ... 20 ga will work, but what you loose is the slower speeds, since you would have to use a higher voltage to force the same amount of current through the conductor. ...
... 20 ga will work, but what you loose is the slower speeds, since you would have to use a higher voltage to force the same amount of current through the conductor.
...
Beg pardon, Leo Broadwayensis, but what he would lose is the top end....the speed. If he has to dial in more voltage to get the unit underway, then he will run out of available/deliverable voltage when he wants higher speed at the top end. And this problem with 20 gauge wires used as a bus would probably only be manifest to a neophyte with runs of about 12' or more, or when he added several hard-working locos at the same time.
Crandell
selector BroadwayLion: ... 20 ga will work, but what you loose is the slower speeds, since you would have to use a higher voltage to force the same amount of current through the conductor. ... Beg pardon, Leo Broadwayensis,
BroadwayLion: ... 20 ga will work, but what you loose is the slower speeds, since you would have to use a higher voltage to force the same amount of current through the conductor. ...
Beg pardon, Leo Broadwayensis,
Him not gonna be happy, Crandell. King of Beasts bring down prey for far lesser crimes than that. Him gonna make you eat your words before him eat you.
The ideaof electrons traveling on the surface is the "skin effect" and is minimal at 60Hz powe rline frequencies and even DCC frequencies. The only reason I use stranded for my bus lines is that it is much easier to pull around and through the benchwork then heavy guage solid wire.
My layout pretty much fills up a 10x15 room, and I use #14 for my bus with no slowdowns or power loss. The longest run is about 25 feet.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Eh... Wire is part of the circuit. It adds resistance. Resistors affect current. The result *could* be a loss of voltage, but in my experience that means that suppose a motor will start to run at 2 volts. But suppose it takes 5 volts to get any current to flow through your wire, that means the first electricity that your motor sees is at 5 volts.
In any event, *I* was able to achieve lower speeds with the bigger wires. LION does not really care about the top speeds, NYCT does not travel that fast. Indeed my trains already run faster than the prototypes.
BroadwayLion Eh... Wire is part of the circuit. It adds resistance. Resistors affect current. The result *could* be a loss of voltage, but in my experience that means that suppose a motor will start to run at 2 volts. But suppose it takes 5 volts to get any current to flow through your wire, that means the first electricity that your motor sees is at 5 volts. ...
Eh... Wire is part of the circuit. It adds resistance. Resistors affect current. The result *could* be a loss of voltage, but in my experience that means that suppose a motor will start to run at 2 volts. But suppose it takes 5 volts to get any current to flow through your wire, that means the first electricity that your motor sees is at 5 volts. ...
Yes, the available amperage would depend on the voltage supplying, or conveying, it. But once the motor gets enough volt/amps to turn over at all, that is the start voltage for that system of supply and driven mechanicals. It could be 15% of the range, 55%, or 80%, but whichever extent of the range it is that the motor starts to turn, that will be at the lowest speed, not the highest. What our user will notice is that, when he turns his dial up to max voltage, he'll still only be at drag speed. If he turns down the dial, he'll slow to where he started off at a scale mph crawl.
Having been at this DC powered model train thing for about 40 years, and being an electrical control system designer back in the days of relays, I have a slightly different take on this.
Why does a DC layout need a bus wire at all?
My average isolated electrical track section (many of you call them "blocks", I choose not to use that signaling term) is about 20 actual feet long. Each has a single pair of feeders that come from the cab assignment system (some may use rotary switches or toggles, I use relays). Those relays are seldom more than a 20' run of wire from the track section, usually much less.
All rail joints within the track section are soldered, the feeders are typicially 16 guage wire.
I do a have a throttle bus system of 12 guage wire which connects all the relay panels to the radio throttle base stations. Each of these throttle base stations is powered by its own 5 amp, 13.8 volt, regulated power supply.
Never, in any DC cab control layout I have ever built or been involved in th building of, including a well known club or two, have I seen a need for multiple feeders to a given track section (block).
My trains don't suffer and voltage drop problems, and I run three and four powered units per train in amny cases.
I don't know the cross section or resistance of code 83 nickle silver rail, but I suspect it exceeds the specs of 12 guage wire - since DC layouts are almost always broken into track sections (blocks) why would one need a bus and multiple feeders?
Just solder the rail joints.
Sheldon
LION has 1000' of track, all DC, no blocks. LION uses an Analog Automation System. Him has 10 v DC regulated power supply putting 15 Amps on the tracks. Eight or more trains run at once with up to 12 powered units.
LIONS do not fool around with their trains.
RPAR
BroadwayLion LION has 1000' of track, all DC, no blocks. LION uses an Analog Automation System. Him has 10 v DC regulated power supply putting 15 Amps on the tracks. Eight or more trains run at once with up to 12 powered units. LIONS do not fool around with their trains. RPAR
Please explain Analog Automation System. Onboard radio recievers?
Analog Automation is of the LION'S own design. Actually I call it Automatic Train Control, but I thought the word "Analog" might help with the description.
Regulated DC power is on all of the layout all of the time. There are no blocks.
As a train enters a station, it passes over a series of resistors slowing it down. Once in the station a gap stops the train in the platform. LION has a time clock that releases trains at 15 second intervals, since a train would always leave the previous station at a known time (say :00 seconds) it will arrive at the next station in say 20 seconds, that station will be hard wired to the clock to release the train (pull in a track relay) at :45 seconds. Again the train passes over the resistors to gain speed.
LION has 45 platform edges on his layout, at the moment only four trains are in service, but the layout will support as many as 12 trains all at once.
Last time I looked, there is only one LION here, and controlling 12 trains, or even six trains is on the far side of impossible. When the LION releases a train from the terminal, it runs the layout, making all of the correct stops automatically. LION does not need to worry about a train until it arrives back at the Dyckman Street Station. There he must align the switches for the 242nd Street station, and then give the waiting train at Dyckman a Clear Home Signal to let it enter the terminal.
There are two loops that in normal operation are separate from each other and from the local tracks that host express trains. These run continuously (making correct stops, of course) but do not need to be turned at the end of the line. The Lenox Avenue Statio>n and the Nevins Street Station (both hidden off stage (sort of) can hold these trains during night time periods so that they can be released to "race" with the local trains.
Here is track with embedded resistors. Thes are 5.1Ω resistors.
Here is the clock or timer used to release trains from the stations:
And here is the tower from which the railroad is controlled:
Lion,
OK, simple enough and for your purposes a great system. As noted in my post, I don't care for the use of the term "block" for an isolated electrical section of track, as "block" is a signaling term.
But you do clearly have isolated track sections to effect control, even if they are all connected to the same power at the same time.
True. The left rail as looked at in the direction of travel is ground. The right rail is regulated (+) dc, the trains all move forward. There is no reverse on this layout. Subway trains do not go backwards.
There are power gaps, but not real "blocks" as model railroaders would understand their power districts since there are no cab controls. You cannot isolate one train and operate it as you will.
Actually, the dispatcher does have "holding lights" that are separate from the interlocking system. When illuminated, the conductor must hold his doors open. Perhaps for a connection, perhaps because he is running hot, perhaps because the railroad is all out of joint. Thus if the railroad is backed up, I can hold trains in the stations (by shutting off the relay that would release the train) since there are no train detectors, and because my signal system is just for looks. The LION *could* build a proper signal system to enforce this control, but the LION is not made out of money. Him would need over 200 train detectors: this is not going to happen. The signals operate off of the same time clock that starts the trains, this looks realistic enough and is all that I can do.
Hi Yankee,
Actually I think that skin effect applies only with AC current, and very high frequency at that. Wikipedia says that the skin depth of 60hz AC is 8.5mm. Skin effect might be significant with DCC, because it is roughly equivalent to a few khz. When I Googled "skin effect" one of its' offerings was for a skin effect calculator, but I didn't go there to look at it. 14ga wire can carry several amps over tens of feet with nearly imperceptible losses, so it should be plenty for any room sized DC layout.
Regards
Chuck Lee
Skin effect is minimal at the frequencies DCC works at, now at RF the range, it does become a big deal.
Still, using heavy wire for the bus, like 14AWG, is a good idea, as too much resistance can cause all kinds of problems, and most of those problems are caused by inadequate wiring. Cheaper to do it right the first time, than burn out a $100 Tsunami or melt a truck side frame first.
betamax Skin effect is minimal at the frequencies DCC works at, now at RF the range, it does become a big deal. Still, using heavy wire for the bus, like 14AWG, is a good idea, as too much resistance can cause all kinds of problems, and most of those problems are caused by inadequate wiring. Cheaper to do it right the first time, than burn out a $100 Tsunami or melt a truck side frame first.
Respectfully I have to ask - did you read the title of this thread? or all the posts in this thread?
The OP is using DC, he has no Tsunami's to burn out. Skin effect was just a side disscussion, a side disscussion that has no bearing on the OP's situation in fact.
Again I will repeat my view, most properly planned DC systems do not need a layout bus, but may need a throttle bus depending on the type of DC system. But even with that, each isolated track section should require only one feeder which can often be 18AWG or 22AWG with no problem.
ATLANTIC CENTRAL Having been at this DC powered model train thing for about 40 years, and being an electrical control system designer back in the days of relays, I have a slightly different take on this. Why does a DC layout need a bus wire at all?
It sounds like this works for you but won't work for me for a couple of reasons.
1. My layout is O scale and thus requires more amp draw.
2. I hand-lay my own track using steel rail, I'm not sure of the numbers but I'm certain that steel conducts electricity worse than copper.
3. The lengths of rail I use are 6' and soldering them end-to-end will cause expansion/contraction problems. They need to be gapped.
4. My blocks are up to 40' long.
So, yes, I need to have a buss wire conneced to each piece of rail or I get major problems with trains moving at constant speeds.
Check out the Deming Sub by clicking on the pics:
el-capitan ATLANTIC CENTRAL: Having been at this DC powered model train thing for about 40 years, and being an electrical control system designer back in the days of relays, I have a slightly different take on this. Why does a DC layout need a bus wire at all? It sounds like this works for you but won't work for me for a couple of reasons. 1. My layout is O scale and thus requires more amp draw. 2. I hand-lay my own track using steel rail, I'm not sure of the numbers but I'm certain that steel conducts electricity worse than copper. 3. The lengths of rail I use are 6' and soldering them end-to-end will cause expansion/contraction problems. They need to be gapped. 4. My blocks are up to 40' long. So, yes, I need to have a buss wire conneced to each piece of rail or I get major problems with trains moving at constant speeds.
ATLANTIC CENTRAL: Having been at this DC powered model train thing for about 40 years, and being an electrical control system designer back in the days of relays, I have a slightly different take on this. Why does a DC layout need a bus wire at all?
Being in O scale, you have a larger rail section to be able to solder to, so a larger feeder size is easily doable in the first place.
Nickel Silver, used in all the smaller scales now, only contains 60% copper, the rest is nickel and zinc. Not much different than steel in expansion/contraction or resistance. I have soldered all my rail joints for some 40 years in this hobby - never had any expansion issues. But, it that is a concern, jumpers soldered around rail joiners, just like the prototype, are very effective in allowing expansion but maintaining current flow. I know several modelers who do that even in HO.
40' - not a problem here. Some of my blocks are that long with no voltage drop issues using code 83 nickel silver rail and running as many as five to six powered units on a train. Each of my throttles has its own 5 amp power supply - I can run 5 old style Athearn diesels with no problem - 3-4 amps.
Feeder bus will work, but jumpers at track level or soldered rail joints will works as well - even in O scale with steel rail.
Pardon me while I put on my contrarian hat.
I run analog DC and I do have one rail bus - #12 solid - that connects all my common rail drops to all the places where common rail is supposed to be connected to provide loco power. This is driven by the fact that I might have ten or a dozen open-frame motors, plus rolling stock lights, drawing power at any one time (and the availability of a free roll of wire)
I, too, have rail expansion issues (100 degree annual temperature swing) so I solder jumpers around every rail joiner that isn't insulated. My longest electrical section is about 6 meters long.
With the comparatively short runs of my non-common-rail drops, I have been using #22 wire (sometimes in the form of a twisted pair of #24s - once again, the price was right.) For some of my longer inter-panel connections I'm thinking of going to #18 wire (panels are two meters apart, but the wire run is close to 25 meters.) That requirement is still future tense.
Loss of top end voltage doesn't bother me. Running at prototype speed usually requires less than 9 volts. The full 12<14 volts available at full throttle would result in rollovers on my curves.
No matter what the electrical system ends up looking like, two basic rules:
Chuck (Modeling Central Japan in September, 1964)
Chuck,
If I used common rail wiring, I would use a bus for that as well. But that is generally a different concept than this idea most commonly used in DCC of spreading the distribution of a single feeder to single section of rail that is electrically continious by having a bus with multiple taps connected at various points along that one rail.
I don't use common rail wiring because:
The Aristo Train Engineer is not common wire/rail friendly.
And, since each of my eight throttles has its own power supply, not using common rail provides the "free" operational benefit of preventing operators form overrunning their assigned track section by simply staggering the electrical gaps.
This concept of staggered rail control is integral to my whole control systrem. All my "X sections" or floating blocks as some call them, are fed from both ajoining sections - one rail from each, requiring that the whole route be properly selected before power is available for operation.
No doubt each layout situation is unique and may require different approaches to wiring methods, but the idea that a DC layout with some sort of "block" or "track section" system of control requires muliple feeders per each isolated track section from some sort of bus generally not true.
If expansion is an issue, jumpers are just as effective and likely cheaper and easier to install.
I have a bus, a throttle bus that takes the eight throttles around to all the relay panel locations where they are then connected to the track sections. It is #12 wire. But again, even with "blocks" or "track sections as long as 40', I only have one connection to each isolated section of rail. And have never had issues with voltage drop. My throttles put 13.5 volts max on the rails at a max of 5 amps. I have measured that voltage at all points along some of my longest track sections - all equal.
And, as you mentioned, I have wired a number of DC layouts in the past with wire as small as 22 gauge with no loss of voltage or performance.
ATLANTIC CENTRAL Feeder bus will work, but jumpers at track level or soldered rail joints will works as well - even in O scale with steel rail.
I have wired sections of my layout without a buss wire and found problems with voltage drop.
I really don't want to get in an argument, just wanted to give the OP my personal experiences with it so he can make an educated decision.
You, of course, are entitled to your own opinion based on your own experiences.
ATLANTIC CENTRAL betamax: Skin effect is minimal at the frequencies DCC works at, now at RF the range, it does become a big deal. Still, using heavy wire for the bus, like 14AWG, is a good idea, as too much resistance can cause all kinds of problems, and most of those problems are caused by inadequate wiring. Cheaper to do it right the first time, than burn out a $100 Tsunami or melt a truck side frame first. Respectfully I have to ask - did you read the title of this thread? or all the posts in this thread? The OP is using DC, he has no Tsunami's to burn out. Skin effect was just a side disscussion, a side disscussion that has no bearing on the OP's situation in fact. Again I will repeat my view, most properly planned DC systems do not need a layout bus, but may need a throttle bus depending on the type of DC system. But even with that, each isolated track section should require only one feeder which can often be 18AWG or 22AWG with no problem. Sheldon
betamax: Skin effect is minimal at the frequencies DCC works at, now at RF the range, it does become a big deal. Still, using heavy wire for the bus, like 14AWG, is a good idea, as too much resistance can cause all kinds of problems, and most of those problems are caused by inadequate wiring. Cheaper to do it right the first time, than burn out a $100 Tsunami or melt a truck side frame first.
In defense of Betamax,
I will say that it never hurts to cover bases. While the OP may be asking about DC wiring, there are probably a lot of DCC layouts that used to be DC layouts - so it seems to be safe, why not wire a layout to handle both, incase a hobbiest loses all sense of reality and goes over to the dark side? =P
The one thing I like about solid wire, both for the bus and the drops is if you use the suitecase connectors to simplify the wiring, less chance that you would sever some of the strands. I also like using small solid strand wires to solder to the rail vs stranded which you have to twist up and keep orderly.
Rio Grande. The Action Road - Focus 1977-1983
The real kicker is the same thing would work fine in DCC. If the maximum length of each sectionw as 40', and all rail joints were soldered or had jumpers soldered around the rail joiners so there was definite connection between each piece of rail, and you had power being fed to each 40' section, it would work just fine.
Where there might be an issue is that in each 'section' on DCC you could have a lot more powered locos, assuming the power suppyl could handle it. With sectional DC control you have oen train in a section, that's it. 4-5 powered units. In 40 feet of track I could run 2 or 3 multiple unit trains - they'd be too short to justify 4-5 powered units on each one, so maybe that would never really come up, unless the section included a stretch of main line plus a large yard with multiple switchers working it, but that's getting away from duplicating the DC wiring, since in DC the yard would be a seperate section from the main, unless you really never wanted to have someoen run a yard job while another train ran past on the main.
In short (which we hope to avoid) if your wiring scheme does not show a voltage drop under load with DC, it won't show a voltage drop under DCC with the same load.
What doesn;t work, is sectional track with no jumpers and no soldered rail joiners with just 2 wires to the track. This didn;t work well in DC either, heck I had a 4x8 test track set up using some Bachmann EZ Track adn had FOUR pairs of feeders equally spaced and it didn;t matter if I hooked a DC power pack or my DCC system to it, trains slowed down, Expand that to an 8x12 oval with flex track, with some soldered joints (total joints, far less than the 4x8 sectional track setup), and it ran perfectly fine on DCC with one pair of #20 feeders hooked up. No slowdowns, even with multiple locos on the train. I did have a #12 bus running around that I eventually hooked multiple feeders to, but it did run without. My current layout is actually bigger, and I'm only using #1 wire this time, no #12. It's about 10x15 around the walls of a spare room.
I have a 1958 Lionel O scale. When I was a kid my father had wires going everywhere. I want to install bus and feeder lines. I run 2 engines. My track is O scale 3 rail. When attaching the feeder lines to the track, what connects to which rail? Thanks.