Bus Wires

The two wires you attached to your track with your starter set work well for a 40 x 60″ oval – but as your runs get longer voltage drop over the distance and joints can cause poor performance as your train gets further from the power source. The solution to this is a simple wiring bus. Not only will buses provided better power, on a large and complex layout, they can help keep the wiring neat and easy to maintain.

transformer buses

Start bus wires from the transformer. Busses can travel beneath the platform for a cleaner appearance.

A bus wire is nothing more than a wire, or pair of wires, that carries power from the source around your layout. It can be tapped by feeder wires to connect it to the layout at any interval. These work for track, switches, accessories, etc. We highly recommend using different colors for each of your different mainline and accessory bus wires. This will make it much easier to trace a problem later.

Wire comes in many sizes in solid and stranded varieties. Stranded wire is really a bundle of smaller diameter wires wound together. Wire size is indicated by a number – the larger the number, the smaller the wire. Most house wiring in No. 12, solid wire. For your layout, we recommend a No. 16 stranded bus wire with No. 18 feeders. The feeders do not have to be as large because they are not as long and it is easier to attach the smaller wire to the tracks. Stranded wire offers better electrical flow (electricity flows around a wire, not through it) and it is easier to bend. We recommend adding feeders at least every 10 to 20 feet around the track.

For lights and other low amp accessories, even smaller wire can be used on the feeders. Lighted accessories should use No. 20 or 22 wire. Phone cable works very well for switch motors. It is color coded, easily available and cheap!


Attach feeders to the track to connect to the bus.

You can use “common rail” or “common ground” wiring to further simplify things. As long as your transformers are in phase, you can run one common ground wire for all of your tracks. Then simply run an additional “hot AC” wire for the center rail of each separate loop.The bus wires for your tracks and accessories do not need to follow the track itself directly, but it is helpful if the bus wires and the things they supply are close. This minimizes the length of the feeders and reduces the “spider web” effect under the platform. It is a good idea to keep wires supported by running them through holes in platform supports or using some of the many different wire anchors available at a hardware store.

bus wires

Keeping busses color coded and organized makes wiring and troubleshooting much easier.

In addition to color coding, wire tags are also available to mark different elements under the layout. Maintaining a wiring diagram or planbook with notes that you update with your progress is also invaluable for future additions and maintenance. While this may not seem too important in the beginning when you only have a few tracks and accessories, as the railroad gets more complex, you’ll be glad you took the time to keep everything neat and consistent. [youtube=http://www.youtube.com/watch?v=9JKA0GD_564&feature=g-upl]

47 thoughts on “Bus Wires

  1. the component i use on my layout are the lionel 180 watt power house, the lionel tpc 400 and lionel #990 LEGACY Command Set how do i do a bus wire when using my components

    • Connect the bus wires to the same track connections on your controllers that are currently powering your track. Route the bus wires around the platform and attach feeders as necessary.

  2. Evening, I finally noticed what i did wrong according to Mike’s video instruction. I have to disconnect one of the two leads coming from the terminal strip for my two main lines. Will write back on my outcome

    • No differently. You can use the FasTrack terminal pieces to attach your feeders or use the tabs on the underside of the roadbed of most FasTrack sections for a more concealed connection. Just wire the other end of these feeder wires to your bus.

  3. I have a shelf layout going around a 20×20 room with 2 sidings. I am trying to figure the best way to wire this. I am reading about bus wires and feeders. I assume my bus wire would start at the transformer and circle the room and the feeders will tap into the bus wire and connect to the track at intervals. Is this correct? What is the best way to tap into the bus wire? I talked to some hobby store folks and they suggested wire from transformer to a bus (square plastice piece with one power in and 10 power outs). Then run the spider web from that point.At least it keeps the transormer clean but still is a wiring mess on the shelf.

    • Scott,

      Avoid the spider web method unless you plan on using MTH DCS which seems to prefer that style of wiring. A single bus wire with short feeders to the track will be much cleaner and more efficient. Simply run your bus wires around the layout and add feeders from there to the track at regular intervals. Make sure you have feeders on either side of your switches for the sidings.

      You can connect the feeders to the bus in a variety of ways. The most direct is to strip a small portion of the insulation from the bus where you want to attach the feeder. Wrap the smaller gauge wire around the bus and solder.

      If you want a no-solder solution, install a terminal block at the location. Cut the bus wire and use crimp connectors to attach each end to the block. You can then put a third crimp connector on the feeder and attach it to the same terminal. (I would still solder the crimp terminals on however, so you’re still getting out the iron.)

      Some modelers use “suitcase” connectors which are a snap-on connection for two different gauges of wire. These are available through electrical supply sources. I have heard several concerns over these however, especially in regards to problems in humid environments. So while they are easy, they do come with a potential price.

  4. Do these bus wire methods also work for the new LionChief systems? I have extended a LionChief starter set to a size of about 12′ x 12′, and the performance of the train is noticeably worse when I get further from the FasTrack section that connects to the power adapter. My plan is to start the bus wire at that FasTrack section (connecting the end of it to the tabs underneath), and run the bus along the entire length of the track, dropping leads every 5′ or so for even power distribution. Any special bus wire advice for LionChief users?

  5. Hello, I have found these threads to be very informative, but I have a few questions.
    I just acquired a LionChief set and it comes with the wall-pack, which is rated at about 30 watts.
    I am planning on using 2 sets to create a Dog Bone Layout and possibly run 2 trains at once (will be using bus wiring at 2 points).
    1) How much can the standard 40X50 layout be extended before the wall-pack becomes inadequate ?
    2) How can the wattage be increased?
    3) What transformer could I use in the event the wall-pack is not enough?


    • You can extend the layout well beyond the 40×50 loop with the wall pack as long as you use bus wires. Making the layout bigger doesn’t draw any extra amperage – adding more locomotives, lighted cars or accessories will. You will see some voltage drop across the rail joints. This can be mitigated by busing the power to two locations as you suggest (probably adequate for a loop this size) or also by soldering jumper wires from one track section to the next on the underside of the FasTrack.

      We have successfully run two LionChief engines on a single loop powered by one wallpack, so your power supply is adequate for that. Its wattage can not be increased however.

      If you want more power, any of our conventional transformers can be used. A CW-80 will work well. You can also upgrade to the GW-180 and have more than enough power to spare for your two trains on this layout, accessories, and future expansion. If you are going to add any lighted accessories to the layout, I would recommend putting them on a separate power supply from the trains. This way they will not draw off of that amperage and you can set the voltage at 14V which will not burn out the bulbs as quickly as 18V. Our 1.8 Amp accessory transformer will be fine for that, or you could also use a CW-80.

      • Hello, I stumbled across the while trying find a similar solution to NTillero comment above. I too have a LionChief set with a wall pack and along with a lot of extra track to simply run the one train around the room. I believe I understand the concept of bus wiring and feeders to the underside of the track, but I am unsure of where to start the bus wire since there is not transformer?

  6. I’m planning a 20X20 shelf layout with two loops. I’m assuming I would use two lionel power bricks and two bus wires with four feeders in each of the corners for both loops. Or is it better to put the bricks in opposite corners each handling half of a loop?

    • By using the bus wire, you can place the bricks anywhere you’d like, it won’t make any difference. You are probably better off using one brick for each loop to simplify your wiring.

  7. Hello.

    I will be acquiring a lionchief ready set and will be expanding it via the “8” expansion pack; will be doing the bus wiring in 2 places to mitigate voltage drop.
    I also plan on bying another lionchief model and run both at the same time.
    Questions for the experts:
    1) Wil the stock wall-pack provide enough power to run both models (an their respective cars) simultaneously?
    2) What is the maximum number of trains/cars I can run using the stock wall-pack?
    3) In the event there wall-pack does not provide enough power, how can the power be increased?


  8. Woops, I see that my original question has already been answered.
    Bute here I go with more questions.
    1) I have an 80 watt AC powerbrick from the original 2 piece CW-80, can this be plugged into the powertrack in lieu of the original wall-pack?
    2) If I go the GW-180 route, how will I wire this to the track?

    Thanks again and apologies for the duplicate question.

    • No problem!

      Any power supply that can produce 18V AC or DC will work with the LionChief sets. Simply wire the pack (your CW-80 brick, the GW-80, etc) to the track connecting the AC ground to the outside rail and the AC Hot to the inside rail. You can use a pre-wired FasTrack section or, solder wire leads to the tabs which hold the rails in place on the underside of the roadbed. Making multiple connections in this way via a bus wire will provide much smoother operation and you can hook up your wires to any straight or curved section.

  9. Thank you for the quick response.
    So just to be sure, I can just go ahead and plug the CW-80 brick (6-14003), bypassing the controller directly into the fasttrack where the wallpack would be plugged in and that should do it?
    Also, this should be enough to run 2 lionchief sets and 2 remote switches?
    Will be a simple layout, just wanted a bit exciting so that my 6YO and I can run trains at the same time.

    Thanks again, your knowledge is highly valued and appreciated.

    • I would check the output of the brick first to make sure you are getting an even 18V of power and not more. (The trains will actually run on a little less so if you don’t see exactly 18V, don’t worry.) That should be adequate power for the two trains and switches. You may find the switches run better on 14V. At 18V, the bulbs will also burn hot enough that extended time on may cause the lanterns to melt. Putting these on a separate power supply, or using the CW-80 controller and the accessory terminals with the voltage set to 14, will solve that if you do run into any problems. Have fun!

  10. I have wired my medium size layout using a bus as in this article. I am using both a Cab 1L and now I have a Cab 2 system. I have a couple of MTH protosound 2.0 and 3.0 locos. According to the DCS manual they want a star pattern on not a bus. Will I have trouble if I add a DCS system to the mix?

    • I have read varying accounts on this from others who have wired their layouts for both systems. Some have no problems with DCS and a bus wire system. Others have shown definite improvement with a star pattern. Your LEGACY system should work fine either way. All I can tell you is to try it and see how it works for you.

  11. I watched the Video on bus wiring and I have a question. You suggested a max wire size of 16 ga. fir the bus Why not 14 ga. or 12 ga.? The longer the run the more the resistance, the heaver gauge will help to cut down on resistance.

    • If you are building a very large layout, then yes, increasing the size to 14 or 12 ga. will provide less resistance. For most typical layouts however, these wire sizes will provide excess capacity at the expense of flexibility. If you’re not making a run of more than 40 feet, 16 ga wire will be more than adequate.

  12. I have a large layout with 3 loops of Fastrack (approximately 80, 60, and 40 feet around). I am planning to do bus system as described in the video. I have 16ga for the bus wires and 18ga for the drops and I m planning on a drop every 6 to 8 feet. At each drop on the hot wire to the center rail do I need a drop to the outside ground rail also or is one ground drop on each loop sufficient?

    • You should have feeders to a ground rail as often as your AC hot rail. You only need to drop a feeder to one of the ground rails however. There is a bus bar on each section of FasTrack (except the accessory activation / extender tracks) that connects the two outside rails. It does not matter which of these rails you connect to the bus.

  13. OK thanks!! The video was very helpful. I have been experiencing problems with engines slowing down and stopping etc. (running via TMCC) and I hope this solves my problem.

  14. Hi Lionel. I have been viewing the videos, reading the instruction manuals for both the Legacy 990 system along with the TPC400 & reading the blogs. The Legacy manual says to run 14 ga wire from my conventional transformer to the TPC400 and then to the track via a bus because the wire gets too hot working with the TPC400. However, you recommend in the blog & video to use 16 ga wire for the bus & 18 ga for the feeders. Which method is correct and safe?

  15. I have a loop layout approx 60′ in length. I ran a bus wire around the entire loop and connected feeder wires approx every 10′. I’m having problems with the train slowing in some sections and actually slowing to a stop at one point. Do you have any suggestions to fix this problem? BTW, I’m using a lionel GW-180 watt transformer

    • There could be several common problems. First, check your track power with a volt meter to see how much power is getting to the rails at the points where the train is slowing. You may have a loose electrical connection in the bus or feeders which is preventing power from getting to the rails. Another common issue is simply dirty track and wheels. If the problem has gotten worse over time, this is almost certainly the culprit. Track and wheels can be cleaned with our track cleaning liquid and eraser, or with a paper towel and some alcohol or Goo-Gone. Don’t forget the center rollers under the locomotive as well.

  16. new to all this. so I run 2 wires from transformer around layout. one ac hot and one ground. do I leave terminal track hooked up to transformer. and red is ac hot, correct and center rail. then drop wires to this wire at different places around the track. I tried that and my green light on transformer was blinking. didI connect to wrong rail possibility. thanks ralph

    • It sounds like you’ve done everything correctly. You’ll want to go back and make sure you don’t have any connections between the outer and center rails or anything metal that could be laying across them to cause the short circuit.

  17. I need something that can support some lamps and other accessory’s. I wan’t to run it through as many transformers possible. What would I buy?

    • I’m not sure what you mean by “run it through as many transformers as possible.” If you are looking for a transformer to run just lights and accessories then our 6-32923 36 Watt transformer or 6-14198 CW-80 transformer would be adequate for most small layouts.

  18. I recently rewired my layout (3 loops of 80, 60, and 40 feet around) with bus wires and drops every 6 to 8 feet per advice from this blog and it is working well. I have one problem left. After running a while the engine on the outside loop gets a spike and speeds up for a few seconds. I have TMCC and the CAB controller antenna is broken. When the spike happens it acts as though I have increased the speed via CAB speed control. Could it be bad speed controller on the CAB ? Or interference on the TMCC ? I am thinking of purchasing a CAB-1L as I have a few Legacy engines.

  19. Can you use a SPST instead of a SPDT toggle to control power to an insulated hot rail track block? The SPST toggle is also just an “On” and “Off” switch.

  20. Yes you can. The center rail is the HOT or + part of the two wires that go to the track. It is common to use SPST toggle switches to control such things as sidings, just by isolating the center raid for that section.

  21. Just to confirm: With Phased transformers, does the hot wire of track activated animation like a crossing gate get attached to the Accessory transformer’s hot wire buss wire? But, with non track activated accessory, like parking lot lights, lights in store windows and the like, does the accessory wire get attached to the Accessory transformer’s own two buss wires. Both ground and hot. Correct? What about switches (FastTrack)? Does the hot wire also just get connected to the Accessory Buss? And, what about the coupler track? Finally, just to make sure, with phased transformers and an accessory buss system, there will be two wired at the common (black) terminal and only one at the red? Corrrect?

    Thank you very much

  22. Problem: Train goes like gang busters on the portion near the vintage “ZW” transformer with trottle pulled back. But requires full throttle once the train crosses a 022 switch going to the “back-side” and train just “limps along”.

    Questions? How to prevent this?
    Possibilities: Need extra feed on back side?
    Track joints need to be sanded inside the connecting pin-holes?
    022 switch(s) are causing mischief?

    DETAILS: It ist 4′ x 7′ oval with (4) 022 switches. One pr of 022’s provides an alternate “Main-Line” parallel to and inside of the outermost loop. The other pair provides a diagonal track from the back side (farthermost) from the Transformer to the alternate “Main Line”. The track and switched are vintage Lionel “O” gage from the early 1950’s

    SOLUTION: What steps do you recommend?. Thank you for helping me “stay on the advertised” (imaginary schedule).

  23. I have a really goofy question that will probably seem very amateurish, but I am super new to all this (we all had to learn sometime)….do the feeder wires attach from the bus to the outside rails on Fastrack (which are connected via the bus bar)? I also am confused as the need for a ground – where to connect it on Fastrack (center rail?) and then where to connect the other end of the ground from the track? As you can see, I am a total newbie! Thank for the help and not laughing at me, I just don’t want to fry all these beautiful pieces of Lionel equipment I have.

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