EddieP Remember to keep at least a foot of separation between the track bus and the control bus. If the two are placed to close for any distance crosstalk will occur. This will interfere with the digital signaling.
Remember to keep at least a foot of separation between the track bus and the control bus. If the two are placed to close for any distance crosstalk will occur. This will interfere with the digital signaling.
Mine run in the same bundle for almost 32 feet with no problems at all.
Dave
Lackawanna Route of the Phoebe Snow
If one main is normally eastbound and the other is normally west bound then your right and left rails are reversed. If there is a crossover and both tracks are wired the same then they are not reversed. Regardless, if you are consistent in which rail is Rail A and which is Rail B then they can both come off the same bus. Direction is irrelevant to the bus.
Picture a dogbone - NOT a reverse loop, a simple dogbone with a narrow neck, which is the double track area. If the rail nearest the front of the table is the A feeder, and the second rail of the track is the B feeder, then when you come back around the other side, it's the rail furthest to the back that is the A feeder, and the other rail is the B.
So the feeder order from front to back of the table would be A - B B - A is the layout has a simple turnback curve at the end with no reverse loops or crossovers.
If the layout is simply two concentric ovals, with no turnback curves, than indeed the feeder arrangement would be A - B A - B
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Phoebe VetI see no advantage to a second bus. If your double track is going in opposite directions, it is just a matter of reversing the A and B rails. If you look at the images I posted you will see that multiple tracks in both directions all come off the same terminal strip. Just keep track of which is rail A and which is rail B. Color coded wires are essential for clarity.
Sorry for jumping in, but I find this statement confusing. I didn't see any image, which probably adds to my confusion. If there is double track, like a double track mainline, each pair of rails is wired identically. There is no reversing of the A and B rails. Now if you are talking about a reverse loop, that is obviously a different story. I guess I don't understand what you mean by going in opposite directions.
otp777 I have read you can run the main bus along the back of the layout and then use sub buses from that. This way, the main bus can be placed "out of the way" and it does not have to follow the track route, just the layout board. It seems this would be easiest to install along with the other fie tips. Steve in Missouri
I have read you can run the main bus along the back of the layout and then use sub buses from that. This way, the main bus can be placed "out of the way" and it does not have to follow the track route, just the layout board. It seems this would be easiest to install along with the other fie tips.
Steve in Missouri
It's easier to reach if it runs on the FRONT of the layout.
You can do the drops from the rail in 28 gauge wire about six inches long and solder that to a long length of 14 or 16 gauge wire to the buss with no loss of voltage. If for any reason the buss lines can not follow the main line it is OK to run smaller sub buss lines using larger wire. No one likes to work upside down under a layout for any extended length of time so routing the buss in a convenient place and using a sub buss for inaccessible places is great. Small diameter feeders should be as short as possible not only for voltage drop but as a safety device also. If for some reason the booster does not shut down during a short the small diameter wire will heat up until something fails. Better to have a six inch piece of melted wire than a 24 inch piece. Always do the quarter test on new track and wiring to make sure that the wiring is capable of handling the current. Another benefit to running sub buss is that as your empire grows it is easier to break it up into districts later on.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
On my current layout, the bus wires follow the double main line.
But, like you, I have thought about running the bus wires down the center of the bench work on my next layout.
I don't think that voltage drop is a real issue with added length of the feeder wires.
That said, the real issue is the use of longer feeder wires which means more wire and more cost than if you used shorter feeder wires.
Rich
Alton Junction
Dave is correct,,,,,I have found however,,that it is much easier to remember,N and S, North and South for rail description,,N being alway's,when looking at the rail the top and S being the rail below,,My feeling is such that a lot of people consider,the first rail at the bottom,is a A and B,at the top...I've run into that before,with trying to help people,with A&B rail designation......Just My Thought!!
Cheers,
Frank
It depends on whether or not there is a crossover connecting them and which rail is rail A on each of them.
Okay... one more quick question on this topic. Do the two tracks of a double track mainline need to be insulated from each other? I've searched for an answer in the forum here, but can't find any specific mention of it.
What were the odds of two Franks discussing bus wiring at the same time? But I'll bet one of them knows more about how to wire a model railroad than the other. Guess which one...
My wife of 45 years accuses me of being confused sometimes, too.
Dave,
I just had to reread,everything,,,,I thought you were talking to me,,,,you were talking to Frank B...LOL...
Frank:
I see no advantage to a second bus. If your double track is going in opposite directions, it is just a matter of reversing the A and B rails. If you look at the images I posted you will see that multiple tracks in both directions all come off the same terminal strip. Just keep track of which is rail A and which is rail B. Color coded wires are essential for clarity.
If you compare the two images you can see an error I made. I put the two strips too close together. In the second image you can see that I moved the rail B strip up about an inch. The G strip is command station ground. The small strips are 14VDC
Dave, as a matter of fact I did notice that you've labeled everything for easy reference. I have a label maker ready to go and I was intending to keep track of every single wire, where it goes and what it's for. I've seen pictures and videos online of layouts which show the layout's wiring. All with an absolutely horrific twisted spider-web of spaghetti which to me would seem like an impossible task to sort out if a problem rears its ugly head.
Up above one of the replies I got suggested that perhaps I could go with two seperate bus lines, one each for my double track mainline. Is this necessary, is there any advantage to doing it? Obviously it would double the cost of the wire required, but if there is some benefeit derived from doing so, then I would go ahead and do it. Most of the info I've come across more or less assumes a layout with a single track main. Is there a different approach to wiring a double track layout?
Frank B.
Dorval, Canada
Dexter:
Thank you. One point you didn't seem to notice: LABEL EVERTHING!
One snap relay is wired in parallel with the snap switch that controls a siding. The main line next to it has a crossing signal activated by the BDL-168. When the switch is thrown for the siding, the snap relay puts an additional crossing signal on an intersecting road in the circuit with the one on the main line.
The other one turns a set of building lights on and off.
On a different board I have two more of those snap relays wired in parallel with the snap switches that control my two program track sidings. When the switches are thrown to the sidings, the sidings are wired to the layout power so the engine can be driven in and out. When the switches are closed to the main line, the sidings are wired to the program outputs. One siding is to the Command station program outputs and one is to the PR-3.
Phoebe Vet My bus is 54 feet long. It runs along the front edge of the layout and each 8 foot section has a swing down board where connections are made without crawling under the layout. The under table connections are made with push on connections, so any changes are easy. Because my connections on the swing down boards used terminal strips and a jumper, when it came time to add detection, I just removed the jumper on the "A" rail side and wired in the BDL-168 right there on the swing down board. No crawling under required.
My bus is 54 feet long. It runs along the front edge of the layout and each 8 foot section has a swing down board where connections are made without crawling under the layout.
The under table connections are made with push on connections, so any changes are easy.
Because my connections on the swing down boards used terminal strips and a jumper, when it came time to add detection, I just removed the jumper on the "A" rail side and wired in the BDL-168 right there on the swing down board. No crawling under required.
Wow, that's some very neat wiring! This is exactly what I am striving for. Everything neat and orderly and easy to troubleshoot if necessary. Dave, in your pictures I noticed that you have a couple of what appear to be Atlas snap-relays. I was wondering what exactly you are using those for in a DCC layout as I thought that the Atlas system of products was intended for DC wired layouts.
I would definitely use 14ga solid wire for the main bus and then if you want to branch off to reach other areas, still use the same wire. I use terminal strips for many connections under my layout and also label everything. I use short 4-6" long 24 ga solid for feeder connections to the track and then 22 or 20 ga stranded to the buss. All my buss connections are made with 3M suitcase connectors and haven't had any problems and they are easy to use when upside down under the layout. You can buy th 14ga solid wire at Home Depot or Lowes by the foot so you don't waste any. You definitely want to do this part of the layout right and not wish you had later. Just my thoughts.
-Bob
Life is what happens while you are making other plans!
dexterdog I am ready to start on the wiring phase of my layout, but I've been wondering about an aspect of this process which I have really not seen covered . Most sources whether in print or online will say to "run a bus wire under your layout" which is well and good, but my question is: Would you run the wires directly under the mainline route, or would it be more efficient to string them along the length of the layout down the middle? The main part of my N scale layout is 4x16 feet, essentially 2 4x8 tables connected together. A double track mainline runs around the perimeter with a branchline, a yard and industries in the middle. Should the wires follow the mainline track above, or down the middle of the layout? Perhaps in a zig-zag pattern? I will be using Digitrax DCC system to run the trains. What is the conventional method of routing bus wires? Any input would be greatly appreciated.
I am ready to start on the wiring phase of my layout, but I've been wondering about an aspect of this process which I have really not seen covered . Most sources whether in print or online will say to "run a bus wire under your layout" which is well and good, but my question is: Would you run the wires directly under the mainline route, or would it be more efficient to string them along the length of the layout down the middle?
The main part of my N scale layout is 4x16 feet, essentially 2 4x8 tables connected together. A double track mainline runs around the perimeter with a branchline, a yard and industries in the middle. Should the wires follow the mainline track above, or down the middle of the layout? Perhaps in a zig-zag pattern?
I will be using Digitrax DCC system to run the trains. What is the conventional method of routing bus wires? Any input would be greatly appreciated.
Just run a bus down the centre of the tracks, one for both mainlines, or one for each mainline so they are on their own circuits. Depends on whether or not you want two power districts or one…
Buy heavy wire, if you want to have a good idea check out the NTrak standards. You can use stranded or solid, not an issue. Just run feeders off the bus at regular intervals, like every 3' or so. N scale rail is much lighter than what is used in HO, so it has more resistance. For a foot or two, lighter gauge wire for the feeders isn't an issue.
Check your wiring as you progress, so if you make a mistake and cross a wire, you'll find it sooner than later.
The yard can be wired in a zig-zag fashion.
Thanks for all the helpful responses. I have a much clearer idea of how to go about this. I just wanted all the wiring to be neat and most of all efficient. I think I can now go ahead and pretend I'm an electrician.
dexterdog Would you run the wires directly under the mainline route, or would it be more efficient to string them along the length of the layout down the middle?
I would follow the mainline and keep my feeders short. This minimizes the voltage drop due to the smaller wire.
Jim
Dexterdog,
Your comparing apples and oranges,with cable TV and a buss,,,There's voltage in a buss and a signal in cable.. Use 14 ga wire for your buss and 22ga feeders and you won't have any problem's...
dexterdog My concern was the length of any feeder wires from the middle of the layout extending two feet or more to reach the bus. So am I to understand that it is acceptable to attach a "branch" bus to the main bus wires to reach any tracks located in the middle of the layout?
My concern was the length of any feeder wires from the middle of the layout extending two feet or more to reach the bus. So am I to understand that it is acceptable to attach a "branch" bus to the main bus wires to reach any tracks located in the middle of the layout?
Yep, that was my concern too. 2 foot long feeders would probably reduce the current to the track. Yes, you can run a "branch bus" as long as it's equal to or the next size smaller and limit the length. Example: If using a 16 gauge bus, the branch bus can be 16 or 18 gauge. On the other hand, if you run your bus line 1 foot in from the edge on each side, that would leave 2 feet between them in the middle. Therefore, your feeders would only be 1 foot (12 inches) from any bus line, on any side.
dexterdog Electricity is NOT my strong suit. I'll build you a house, just don't ask me to wire it! I thought that splitting a bus wire off into a branch of sorts somehow would decrease the current, sort of like splitting your cable TV feed which degrades the quality of the picture. Now I can see all those wiring gurus out there wincing in disgust at my ignorance, but bear with me folks. I want to do this only once, I want to get it right.
Electricity is NOT my strong suit. I'll build you a house, just don't ask me to wire it! I thought that splitting a bus wire off into a branch of sorts somehow would decrease the current, sort of like splitting your cable TV feed which degrades the quality of the picture.
Now I can see all those wiring gurus out there wincing in disgust at my ignorance, but bear with me folks. I want to do this only once, I want to get it right.
Cable only comes in one size, unlike wire, pipe or hose. With wire, pipe or hose, I can start out big and work my way smaller. Oh, SOLDER joints and connections!!! it really makes a difference in maintaining a good electrical supply (your locos will thank you)
Inspired by Addiction
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Based on your description, I would run the bus line as close as possible to the main line. When it comes to electricity: the longer the run, with smaller diameter wire = more current loss due to resistance. So, if you start out with a small diameter bus, then try to feed smaller diameter feeders, you'll end up losing current to the track.
I run a 16 gauge bus line as close to the main line as possible. My feeders are 24 gauge and don't exceed 12 inches in length. With this set-up, I'm putting the electricity right where I need it. I have a Digitrax Zephyr Xtra and maintain 13.4 volts at all areas on the layout (considering the rated output is 13.8v).
As someone else stated on this forum: "I've never heard anyone complain that they have too many feeders"
I don't think it matters. My layout is a linear design with narrow benchwork, so the bus automatically ends up close to the main track in most places. Whatever location works easiest for you should be fine.
Rob Spangler