I’m just starting in model railroading having only created a N scale on a 4x8 back in the late 1980s. I’m right now constructing the benchwork for a 18’x24’ E shaped (middle peninsula) double main track layout. No reverse loops, cross overs or wyes, except a wye for entering a yard as I couldn’t get a regular turnout to work. I’m thinking about using Digitrax Command station (DCS 240), a second booster and I’m guessing PSX power managers so I can keep my buses to under 30’ I’ve read various books and websites and of course I’m not totally clear on how the system should be hooked up. I’m going to use 14 gauge solid wire for the buses and probably 20 gauge solid for the feeders and solder the feeders every 6’ and most if not all the rail joiners. Using Atlas code 83 for all track. There will be one small yard. I believe I understand that I have to have a LocoNet cable running from the command station to the booster and another for the cab bus. Not sure whether I have to also have a ground wire connection also to the booster as Wiring for DCC Alan Gartner website kind of indicated not to as this causes a loop since the LocoNet cable has a ground built in, but then he shows something else about cutting two of the wires in that LocoNet cable instead and running a ground??? He also mentions about not connecting your booster outputs together, but not sure what he is referring to. Also, I guess I can run the bus wires to the PSX device and run the bus wires from there to the individual power districts (gap’d) so that I can get by with only one extra booster. I’m also confused about the cab bus setup and whether or not I need to have UP5s connected to the main bus wires for each power district??? I may also use a IR panel/throttle too, as radio wouldn’t work out since this system will be in a steel building.
Going to use Tortoise switch machines for all turnouts and I believe I can
You want to connect the ground (really a common) between the command station and booster with at least as heavy a wire as the bus. This is pretty important, as any slight voltage difference when crossing the gaps from a section powered by one to a section powered by the other needs a path, and without the heavy common, it uses the thin wire in the Loconet cable. Do NOT connect any of these to the easrth ground, such as the ground pin of an electrical outlet.
Do not connect the UP5’s to the track power, if you ever intend on installing block detection. Depending on how many throttle you plan to use plugged in, you may want to supply aux power to the UP5 via the power socket on the side.
For frog power with the Tortoise contacts, the same #20 feeder wire is fine. The frog is small and can never have more than one loco on it at a time, so there will be no high current involved. You can use the sam colors as the feeders for the two bus lines, and green for the frog because, as Tony Koester says, frogs are green.
As a long-time Digitrax user with a similar-sized (HO) layout, I’ll offer my opinions:
Use stranded instead of solid for your bus. MUCH easier to work with!
Consider 22 or even 24 gauge for your feeders (keep them short). Depending on how you solder them to your track, the smaller gauge will be less noticeable.
Unless you’ll have a zillion sound-equipped N-scale locos running at the same time, you probably won’t need a second booster.
Use one (or more) Digitrax BXP88(s) instead of the PSX. For roughly the same price as the PSX4 you’ll get twice as many breaker sections, PLUS detection if you ever decide to add signals or automation, PLUS transponding. (Okay, very few folks use transponding so you’ll probably just turn it off in the BXP88 anyway.)
Yes, you need the “ground” (it’s actually a reference ground, not an earth ground) between the CS and the booster (if you need one - see #3). Do NOT depend on the LocoNet ground conductors to provide that function, as it must be able to carry the booster’s entire output amperage.
Do NOT cut any of the LocoNet wires unless you FULLY understand the reason for doing so on YOUR layout. For the vast majority of layouts that’s something that not only isn’t needed or recommended, and it could cause other issues.
I recommend that you don’t connect your UP5’s to the power bus. Use a dedicated DC power supply in the side 2.1mm coaxial jack instead. I use a 15VDC regulated supply.
Use the same wire gauge for powering your frogs as for your other feeders.
A track plan would really help sorting out your questions.
My first question would be where would you place the command station? Using a track plan would determine the arrangement and length(s) of the buss(es). From that we (you) can determine whether a booster would be needed.
My second question would be how do you plan to power and control the Tortoises?
I agree about not connecting track power to the UP5s.
Randy, thanks again for responding to my questions. Based on your, Robert and Stevert’s response I understand to use a ground 14 gauge wire from the CS to the booster or boosters and not cut anything on the LocoNet cable. I also think all of you are telling me not to connect the UP5s to the track bus and if needed to use a separte power supply to them if I will be leaving throttles connected. Will use the #20 feeder wire for the frog power as you indicate.
Stevert, thanks for responding to my questions. I agree the stranded wire is more flexible and was initially going to go that way until I read both Larry Puckett’s and other book/websites that recommeded/used solid wire for bus and feeders (already bought the bus wire, just not the feeder wire yet). Everyone of these books/websites I read gave me either a 20-24 gauge range or 18 -22 range for feeders and kind-of-suggested soldering every track or 3’ for the ligher gauge, so using this as weill as the limits on the suitcase connector wire sizes. I decided to go with the middle #20 on Puckett’s range. Hopefully, this will not be an issue with soldering (soldering newbie).
I don’t remember anyone of the books or website talking about the BXP88’s and I just tried to read up on them and not clear how they are used as a power managers for setting up power districts or simply for allowing me to keep my track bus under 30’. I was going to use the PSX-4 (that was what they recommneded or the Digitrax PM42) to run the bus wire from the CS and booster to them and then from there in both directions on the double main lines of which there will be two sets in every location on the setup so that I don’t exceed the 30’. Perhaps I should use the BXP88(s) instead, but not sure how this works and if it is more complicated I might have to go the other route (one of the reasons I made sure I didn’t have reverse loops and other more complicated track arrangements).
As you suggest I will run a ground wire from the CS to the booster or boosters and not cut any wire on the LocoNet cable and not connect the UP5’s to the power bus and use a 15VDC power supply instead. Will use the same wire gauge as the feeders for connecting the Tortoise to the frog.
Thanks again for all your help, I really appreciate it as this DCC stuff is making my head spin (don’t remember my head spinning as muc
I think the only reason these sites recommend solid wire for the bus is because the love to use suitcase connectors, most of which only work with specific sizes of solid wire.
I hate them and will never use them. And it is infinitely easier to pull easily bendable strnaded wire in heavy gauges through the benchwork. Yes, everyone will say “But they use solid in house wiring” Yes, and it is a pain to feed through rafters and in and out of boxes.
My feeders are 20 or 22, I forget which, but it is a 2 conducotr loosly twisted wire sold as alarm wire. It pulls apart easily into two individual pieces and it matched the color of the bus wire. Seems small enough for HO. N scalers might want to use phone wire.
Robert, I used the Atlas track planning software to create the plan and exported it to a jpeg file, but being fairly new to the forum I don’t know how to insert the file. Tried the insert image/video, but that didn’t seem to work or actually was clueless on the process. I tried to figure out where I could place the command station without having another booster and just using power managers, but no matter what the buses would be much longer than 30’ The track plan is E shapped(with middle peninsula), with 24’ long representing the top and bottom of the E, middle peninsula 16’ for the middle of the E and 18’ from the top to the bottom of the main part of the E. The width of each section ranges from 3 1/2’ along the top of the E 24’ part, but at the ends 7 1/2 by 7’ and 6 1/2’ for the middle peninsula. The double main lines run along the top and bottom of the entire length of the track plan.
I haven’t really researched in depth how I should power the Tortoise, perhaps using a DC power supply or maybe a stationary decoder?
As you and the others suggested I will not attach the UP5s to the track power.
Again, I want to thank you for your help and maybe help me on how to attach files or images as I’m not sure my explanation above of the track plan helps.
Randy, your obviously an old schooler and me being a soldering newbie, I already purchased the suitcase connectors. I think the last time I held a soldering iron was in 8th grade metal shop in the 60s. I hope this will allow me to connect my feeders more quickly and with less burns. Already having anxiety on the amount of soldering I need to do for the feeders, joiners, etc.
The BXP88 probably doesn’t show up in those publications because it’s is fairly new, and it’s a Digitrax product as opposed to a “generic” power protection device.
But it’s easy to wire: Rail A & B, and that common, from the CS/booster to the BXP88. Then a common Rail A from the BXP88’s RAX terminal to all eight breaker/detection sections, and a separate Rail B from the each of the BXP88 outputs to each of the breaker/detection sections.
As for the 30-foot “rule” - Put your command station in the middle of the backbone of that “E”-shaped layout, fan everything out from there, and you should be fine.
Randy, I agree with you, but I’ve already committed and bought the wire and suitcase connectors. I’m also someone who last held a soldering iron I believe was in 7th or 8th grade machine shop. I’m already dreading the amount of soldering I need to do for feeders to track and joiners.
Thanks again for insight on the size of the feeders.
Stevert, thanks for the additional information on the BXP88. I read the instruction sheet for the BXP88 and the wiring diagram. I noted that the single RAX connection was used to connect to common rail A (one wire to rail A) and that the DS1-DS8 connections were used to connect to the 8 individual gap’d/isolated rail B connections (all of these I assume would actually be my bus wires). It shows only one rail A gap’d/isolated section of track at the beginning and end of the 8 rail B isolated sections. The diagram makes it look like each of these wires are attached to the rails versus acting as a bus wire. So then if these are individual bus wires, which I assume they would be based on length) I still need to keep the longest one 30’ max, but if I only have one wire from the RAX connection as shown to rail A, how do I get 4 30’ rail A and at least 4 30’ rail B connections for setting up 4 30’ long power districts like I would if I use the PSX-4. Do I splice in 4 or 8 wires to the single RAX connection wire? I need to have 4 30’ or less buses from the booster/power manager devices for this to work on my layout. So if I’m using the BXP88 in lieu of the PSX-4 I don’t understand how this would be possible with only one rail A wire connection.
This is why DCC is so confusing, at least to me, with these devices and there instructions/diagrams.
I did try to see if I could place the CS in the middle backbone of the E, but it would require bus lengths of greater than 30’ and some close to 40’ or more.
Again, I appreciate your help, but I think I’m going to have to buy a second booster and if I put the PSX-4 and booster/CS about half way down on the top and bottom of the E long side I’ll be able to branch out 4 30’ long buses and cover the 2 double main lines that run the entire length of the layout, as well as the small yard and hopefully spurs.
Henry, thanks for the information and I’ll make sure I use that screw size and ensure its brass before I do this. Does the hole in the turnout accept the screw without having to tap the hole as I don’t know how or have the equipment or feel that I can do that without damaging that part of the frog?
Thanks again and hope the screw is self tapping or the hole already has the threads.
Rich, I noted your response to rrinker. I believe you were just responding to the difficulty of running house wire, but are you kind of recommending/suggesting that the solid bus wires be in conduit for the model railroad or is that not really necessary or practical, especially because of the feeder connections every 6’ feet or so?
Gary, there is no reason to use conduit on the layout. In fact, if you enclosed bus wires in conduit, how would you attach feeder wires to bus wires? Conduit is used in some areas of the country like Chicago, for household wiring that carries 120 volts AC in order to minimize the possibility of puncturing the wires.
I would offer this thought though about bus wires. I have used 14 gauge solid copper wire on all my layouts with no difficulty whatsoever. I have never used stranded bus wire. In my opinion, use whatever you want for bus wire, solid or stranded.
Stevert, thanks for the additional information on the BXP88. I read the instruction sheet for the BXP88 and the wiring diagram. I noted that the single RAX connection was used to connect to common rail A (one wire to rail A) and that the DS1-DS8 connections were used to connect to the 8 individual gap’d/isolated rail B connections (all of these I assume would actually be my bus wires). It shows only one rail A gap’d/isolated section of track at the beginning and end of the 8 rail B isolated sections. The diagram makes it look like each of these wires are attached to the rails versus acting as a bus wire. So then if these are individual bus wires, which I assume they would be based on length) I still need to keep the longest one 30’ max, but if I only have one wire from the RAX connection as shown to rail A, how do I get 4 30’ rail A and at least 4 30’ rail B connections for setting up 4 30’ long power districts like I would if I use the PSX-4. Do I splice in 4 or 8 wires to the single RAX connection wire? I need to have 4 30’ or less buses from the booster/power manager devices for this to work on my layout. So if I’m using the BXP88 in lieu of the PSX-4 I don’t understand how this would be possible with only one rail A wire connection.
This is why DCC is so confusing, at least to me, with these devices and there instructions/diagrams.
I did try to see if I could place the CS in the middle backbone of the E, but it would require bus lengths of greater than 30’ and some close to 40’ or more.
Again, I appreciate your help, but I think I’m going to have to buy a second booster and if I put the PSX-4 and booster/CS about half way down on the top and bottom of the E long side I’ll be able to branch out 4 30’ long buses and cover the 2 double main lines that run the entire length of the layout, as well as the small yard and hopefully spurs.
As another longtime Digitrax user (1996 is when I got my system) I have a few different viewpoints that other post.
The BXP88 is a replacement for BDL168 (block detection) and the PM42 (power management). It does the job of both of those devices. It also is now a solid state circuit breaker instead of a mechanical relay. This was/is one of the biggest complaints about the old PM42’s. The mechanical relays tend to wear over time and they were not the world’s most friendly when it came to sound locomotives.
It also limits your system to 3 amps per section. Granted if you are pulling 3 amps in a single section, I’d be worried.
As for my personal preference the PSX breakers are still my go-to item. They are very simple devices that serve their purpose. They do have other auxillary functions such as reporting block detection and/or auto turnout control but that is not what I bought them for. They handle sound locomotives like a champ and don’t require any external connection other than track power to function.
From a troubleshooting standpoint, I am not a fan of single integrated devices that do everything. It alot like a multi-tool, they can do alot but only half as well. I prefer to use the right tool for the job.
Having never really been a fan of centralized block detection. I used a third-party solution. RR-cirkits has a block detection system (fully loconet compatible) that puts the detectors (current transformers) at the block they are to detect.
I have a full CTC signalling system on the layout with its all run from a Raspberry Pi. Even though RR-Cirkits has a signalling I used the Digitrax SE8c’s for the signals. I really liked the plug and play nature. This is one piece of hardware that Digitrax did very well!
Again seperate devices will make troubleshooting much easier.
I use digitrax DS-64’s for turnout control power by a seperate 12v accessory bus.
My Ideal Stripmaster works perfectly every time with stranded wire. But since the OP has already purchased solid, solid it is in this case.
I’m not a particular fan of centralized block detection either - nor am I a fan of diode drop type detectors that cause a voltage drop to each block. The transformer type detectors don’t cause a drop, plus you don’t need multiple long bus lines running from the central detector. Granted, you still have multipel lines, one from each section of the circuit breaker, but typically you have more detection sections than you do power districts.
I use solid for feeders - because with solid there’s no chance of a stray strand at the track getting caught somewhere and causing a short. Plus solid is easier to fish down a hole drilled in the benchwork. And holds its shape while being soldered to the rail.