Correct way to wire a DCC layout?

[inobu]

Kvp,

 

You are acknowledging in one sentence and negating in the next. Block detection is a core feature regardless of automation or manual control. It is based on current draw in a particular block. The point more so Is what is done with that information.

 

Just reading manuals isn't going to give you the over all picture. The stopping is possible with just block detection. Utilizing the logic and script element in JMRI allows the block to trigger the events. The speed control setting gives it the ability to time the stopping.

 

The whole point of my contribution is based on my actual experience in building and to convey that I found the best method is to pre-wire the layout to support the full gamit of detection now. Doing so allows the builder the ability to grow the system to its fullest potential if desired.

 

What is your reasoning in not adding block detection to this layout. It's a more advance layout than most which warrants this level of build. I'm curious to know why you think it is a waste.

 

Inobu

[kvp]

I didn't say it's not useful if the layout is going to have automatic block signals, but the owner should decide on that.

 

For automatic stopping, the timing method only works if you calibrate it for each train and each speed setting. Otherwise the only sure way is to detect it physically and for that, a small detection block or a threadle sensor at each stop location is a must. The same goes for auto stop at block signals. (the combined signal goes for block occupancy, while the stop section signal is used to stop the front right before the entry/exit/block signals. If you could calculate this without measuring then you could calculate all blocks and just run single block for everything)

 

ps: my club uses loconet and we know what it can do, but still the whole layout is run manually with fremo rules and it's actually more fun than with automation or even CTC, that i tried last time when we were one signaller short.

[inobu]

Yeah, it's hard to explore in club environment.

 

Inobu

[gavino200]

As usual what I'm going to say will counter what's on Sumida Crossing but what he is saying is true. The issue I found that adds the hidden variable is the geometry of the track. If you are using unitrack and your layout is not square all the savings on the wiring can be lost in 1 or 2 joiners. If the geometry is off the track shifts little by little. This created poor connections and voltage drops. Although unitrack is a build and storage system you can only do it so many times. As time progresses the jointers lose tension on the rails and the connection weakens. This causes the majority of voltage drops on a layout. If all of your track is NIB its not that much of an issue but it still holds true. Some times we can screw up a jointer without knowing it. When you install it there a problem waiting .

 

On a recent N-scale build I used flex track on a 32' of running track with only 2 feeders. I soldered the track hence no problem. I had .08 voltage drop on the farthest point from the feeder. This kinda proves the jointer theory.

 

So, Sumida Crossing theory is sound but you need to adhere to everything else in the build as well.

 

I used 18 awg wire because it sits right at the edge of the numbers. 18 gauge is good for 15 volts and supports 7 to 10 amps. That's good for N-scale. You can use higher if you like but I found it to be easier to work with.

 

You are correct in your interpretation but here is where your own reasoning comes into play. I chose 18 awg as I can tin and solder the wires on the PM4 and BDL connectors not through the holes but lay the wire on the connector. I make sure that I don't have cold solder joints. I use 18 awg through out the layout up to the feeders. One wire with many different colors but less headaches.

 

Here is a hint. I went through the same mindset as SC. I wanted every thing to spec then I realized I was wasting too much time trying to get everything perfect. So you have to make a decision on the things that are not as critical to keep the project going. if not you can get wrapped around the axle and waste time.

 

Remember feeders are blocks. Each color is a block. Each block is a feeder.

Any area where a train can sit is a block.

 

Track 1 is a section (1 PM4 connector) The colors are the blocks. Place isolators on each end or the blocks.

Section 1 Block 1 is the sky blue on the upper left outer track. The wine color is 1-2. Don't be concerned about buying a bunch of BDL's

You can add them later. What it important is you place the isolators on the track and pre-wire them. As long as you have the isolators on top. You can daisy chain the blocks below the layout. When you get the BDL you can unsnap the connector and add the BDL. 

 

 

I guess the tracks and distance but its close enough for this discussion. My layout is off 19 mm vertically and

2mm horizontally. I can gain 2mm by changing a 124mm track piece to a 62mm and a 64mm. 

I can get the 19mm by adding a 45.5mm on the right side and a 64 on the left side of the track. The difference is .5mm which is nothing. This is where the voltage drop issue starts. 19mm isn't much to us but 19 spread across the layout means a lot of loose jointers. These are the little issues that cause major problems when the compound themselves.

 

Inobu 

 

That's a pretty accurate schematic of my layout. Did you make it on 'Anyrail'? I never thought of using a design program to digitally recreate my layout in order to mathematically correct the track geometry. If you saw my track up close you'd see some areas with seriously bad geometry. I'm spend entire nights down in that basement trying to correct the geometry. Not so much for electrical reasons. Mainly for aesthetics and to eliminate derailment. I eventually settled on using two pieces of Kato variable track to create acceptable geometry in the near loop of the layout. 

 

On SC KenS did emphasize that the biggest voltage drop was at the track level. That's why he strongly suggested more feeders and wasn't overly concerned about having to use 20 and 22 gauge for distribution in many areas. 

 

I found an online wire store that sells wire in a vast array of colors. I'm already planning draw it out first and use extensive color coding. I want to decide what gauges I'm going to use so I can decide what wire to buy. I want to use the largest that is practical and easy to use. Based on your experience I'm going to get 18 gauge.

 

Agree about the BDLs. I'm not getting them now. But I wan't to feed and isolate the track for their later addition. 

 

BTW I really appreciate all the information. :)

[gavino200]

While adding lots of feeders is a good thing, i think that adding too many isolators is not really needed. If someone doesn't want automation, then they are not needed, so you can leave the normal joiners there and just add multiple feeders to the same large block.

 

On the other hand, if you do want automation, then the image above is seriously not enough as there are no position sensor tracks for stopping at the platforms. This means that for automation, you can have a single large block for each loop (with many feeders) and two small train head sensor tracks on each end of each station track. (or just one each in the main direction) This allows accurate stopping while the mainline is handled as a single large block. You can divide that to 3 or more blocks if you want to have more than one train on each loop, but the train stopping position detector sections are more important. That is, if you want computer automation. Otherwise, imho the whole block dectection idea is mostly useless.

 

KV I appreciate your input. Both of your points are relevant. You're saying that if I want an excellently functioning manual system I don't need so many blocks. I agree. Also, that I don't need to actually isolate them. Again agree.

 

You're also saying that if I want to automate, I could benefit from more blocks. Again, I agree. 

 

Part of the problem, is that I haven't given you much information about what my goals are. I have a tendency to build a picture of things in my mind, and gain information by asking a lot of pointed questions, without explaining what I'm getting at. Sort of like the detective in that old TV show 'Columbo'. 

 

I apologize about that. Let me tell you a bit more.

 

It's true that I do a lot of 'low brow' play with my son on the layout. I fully intend to continue that. But he's also a kid who loves mechanics and technology. I love the technology too. Playing is a lot of fun, but he's also at an age where we are really working side by side. It's a good vehicle to teach him about technology, using tools, etc. I had a similar but lesser experience with my Dad when I was kid, by working together on my old OO gauge trainboard. So I know, these projects have some value. 

 

That aside, I'm fairly OCD and I like to do things well. I like to undertake projects that are beyond my skill level and knowledge. I enjoy the challenge and learn a lot. I want to do as much with the layout as I can. But I want to do it stepwise so I can do it well. 

And I want to get this wiring done fairly quickly so that we can get back to using the trains, without compromising on quality or later capability. 

 

So what do I want to do with the layout? As much as possible. Everything. Things I haven't learned about yet or thought of. 

Manual control - sure. Automation - yes. Complex signalling - you bet. Anything that sounds like fun or that I/we can learn from doing - absolutely. 

 

The layout is currently around a third of our main basement room. I wouldn't be shocked if it expanded later to take over the whole room. I could even demo the wall and expand into the relatively large washroom and storage area right next to it. I could even consider moving to a different house if need be to accommodate the project. Who knows. 

 

Doing extra work is not an issue.

 

So thanks for your contribution. Please continue to point out areas where the plan can be improved for any use that you can foresee. 

 

The general plan is "quality work now with as much built-in capability for later addition as possible".

Edited January 28, 2017 by gavino200

[gavino200]

 

Digitrax has a lot of feature sets which works into automation. You won't see into a lot of what I'm saying until you actually build and play with it. That's part of why I suggest Digitrax. If someone wants low level automation then I suggest NCE.

 

Looking back you will see that Gavino isn't playing around on his build. He's done a lot so giving him info so he can pick and choose fuels his build which is a good thing.

 

Inobu

 

That's exactly right. I want to learn as much as possible from both of you guys. Goal = most kick-ass layout possible.

[gavino200]

So you are talking about automatic block signals with manual train control? That is possible with the setup above. (will even work without a computer as it only needs the feedback signal with minimal logic) Automatic train stopping at the station won't be possible though, but getting automatic block signals right, based on occupancy detection will work as long as both the head and the tail of each train picks up power and no train is longer than the shortest detecting block. (longer trains need additional power using cars in the middle to trigger the block detection)

 

KV, you clearly know a ton about this. Can you tell me how you would configure my layout for both instances - manual and automatic.

 

I don't mind doing extra or redundant work. I can also afford to buy wire. If there were a good reason to wire a feeder to every single unitrack and isolate every single unitrack, I'd do it. (Obviously that's a ridiculous example, but I think you get the picture)

 

So have at it. What would be ideal setup from your point of view?

[gavino200]

 

 

ps: my club uses loconet and we know what it can do, but still the whole layout is run manually with fremo rules and it's actually more fun than with automation or even CTC, that i tried last time when we were one signaller short.

.

 

I agree. I think manual, will always be more fun. But I'm interested in the challenge of playing with the technology.

 

Also, I like the idea of relaxing in the trainroom, doing some work or reading a book, while the train layout does it's thing in the background. 

[inobu]

Yes, it's Anyrail it also spits out a material list and you can price track material.

 

If you get the geometry right you can eliminate most of the voltage drop concerns. 18 is about right. Only 1 train is in a given block anyway so the current draw is low by default.

 

 

 

Inobu

[gavino200]

 

 

Fifthly ... is that a word? ... Fifthly, check out the Accu-Lites Digitrax Breakout Boards.  For time poor people like me they are an easy wiring solution that does not require soldering.  They will also happily take AWG12 wire ... probably even AWG10.  Each board comes with a simple instruction sheet.

 

 

 

I missed the significance of this when I read it first. If I understand correctly, what this is, is an adapter with a socket for the PM42 or BDL168 that routes the original terminals to a screw-type terminal that accepts larger wires. Thereby allowing a decision about which gauge of bus wire to use, to be made based on voltage/current requirements and wire management preferences, rather than what gauge is suitable for the digitrax circuitboard. Do I have this right?

[gavino200]

You should get a BDL168 for each. This way you can have the right amount of blocks. As you build and complete your layout one has the tendency to add all the bells and whistles. Part of that is signaling (bells and whistles) which requires block detection. Most do not get to that point and fail to see the value. As you start to automate your layout the controlling system needs to know where things are.

 

 

I've decided to work toward this. I'm going to wire the tracks for and eventual setup with a BDL168 for track 1 and 2, and a BD4 for the yards. I may want a BDL for yard 1 at some stage. It's big and often houses a lot of locos/trains.

 

That would made 16 feeders on each main loop, 6 feeders for yard 1, four for yard two, and two feeders for the segments between the yards and the main loops. 

 

Total of 44 feeders. Not terrible considering I currently have 20 feeders on my zero-sophistication Kato 3-to-1 adapter tree wiring scheme.

 

It would at least make the electrical distribution fairly bulletproof. (If I understand correctly).

 

I had figured that these would be planned as follows.

3 subsections for each station platform (short entrance, main section, short exit)

Remaining 10 subsections for each track evenly scattered.

1 subsection per yard track.

 

I had also figured that each of these subsections would be double gapped with it's own feeder. However, reading the manual for the BDL168 I came across something confusing.

 

http://www.digitrax.com/products/detection-signaling/bdl168/

 

Page 8 Fig. 1 Direct Home Wiring Example

 

They show a track setup with one double gap (both rails insulated) for the entire BDL168 section of track. There is a single gap (one rail insulated joiner) for each of the 16 subsections. Is this a mistake in the manual?? What am I missing?

[gavino200]

This likely means that when I redo the system - maybe in a year or so - I'll probably take down all the wiring between the PM42 and the feeders and re-lay the wire. I'm fine with this. I'm sure that I'll learn a lot and make some errors this time around. Hopefully, I'll be able to take what I learn this time and use that knowledge to do a cleaner job second-time round. 

 

Hopefully the feeder wiring I do now will work well with next year's distribution.

 

Next step: choosing wires, connectors, junctions etc, and drawing out my plan. 

Edited January 28, 2017 by gavino200

[inobu]

Let's go back to Kato's DC setup.

 

You have the Blue and white wire. Without either wire connected the train will not work. If you leave the white wire connected to one rail of the track then it's operation is based on the blue wire. The blue wire becomes the control dictating when the train works or not. The white wire becomes the common wire and the blue wire becomes the control wire.

 

With the BDL168 the color wires are the control and the one white wire becomes the common rail through out.

 

Looking at my BDL168. I am using gray,white,green and red for my blocks. Notice the color of the zip ties on the bottom near the connectors. They are the same color of my input control color from the PM4.

I repeat the 4 block colors so I can support the 16 blocks. If not I will run out of colors.

 

In Fig 1. It has 2 tiltid ~~ that indicates the ommiting of positions 5-15 in the diagrams drawing. It's not representing a gap in the rails

 

Inobu.

Edited January 28, 2017 by inobu

[gavino200]

Let's go back to Kato's DC setup.

 

You have the Blue and white wire. Without either wire connected the train will not work. If you leave the white wire connected to one rail of the track then it's operation is based on the blue wire. The blue wire becomes the control dictating when the train works or not. The white wire becomes the common wire and the blue wire becomes the control wire.

 

With the BDL168 the color wires are the control and the one white wire becomes the common rail through out.

 

In Fig 1. It has 2 tiltid ~~ that indicates the ommiting of positions 5-15 in the diagrams drawing. It's not representing a gap in the rails

 

Inobu.

 

Yes, I get the that the double ~(tilda) means ,,,,, here.

 

The double gaps I was talking about here are the ones before section 1 and after 16

 

So that's a double gap at the beginning and end of the BDL-associated 16 subsections. And a single gap on the control track between each subsection.

 

 

The diagram is just showing the circuitry with respect to the BDL. The BDL (blue lines) is only directly connected to the control track.

 

The booster/P M42 is only directly connected to the common rail. The booster/PM42 is indirectly connected to the control rail through a shared ground.

 

But the single connection between booster/PM42 and common rail doesn't have to be taken literally. That could just as easily be a single wire bus from the booster/PM42 with multiple single feeders between single bus and control rail.

 

For the time being - I can break my layout into four double gapped blocks.

 

Within each of these double gapped blocks (that will be governed/monitored by a BDL) I need to add 15 single insulated joiners on what will be the control rail. They will all be connected to the to the "Blue wire" or specific darker color from my PM42. Later each of these sections will receive a connection from the appropriate terminal of the BDL.

 

What will be the common (eventually) will receive feeders from the light colored bus wire coming from my PM40. Eventually they will come from the single wire bus coming from the booster. There doesn't need to be any insulated joiners between these sections for now.

 

?

Edited January 28, 2017 by gavino200

[gavino200]

 

 

It will still make sense for me to use the Kato wire with the blue and white wires stuck together, for my feeder wire. I have a ton of it. All feeders for one block will connect to a sub-bus from the corresponding PM42 output.

 

The PM42 will take the place of the booster in the diagram from the BDL manual.

 

Later, only the common rail will be supplied directly from the PM42 bus.

The control rail will come from the BDL

The BDL, and PM42 (and booster?) will be connected indirectly through the common ground bus.

Edited January 28, 2017 by gavino200

[gavino200]

This would be the eventual setup for one block

 

 

 

This would be the same block without BDL in place but with feeders and insulators in place for later upgrade.

 

[gavino200]

Alternative "Later" picture with the same feeder wiring as "now" 

 

 

Disregard red wire feeder below section 1

Edited January 28, 2017 by gavino200

[inobu]

Oh it's the sectional gap you are pointing out. It easier seen with the wired PM4 not the diagram. This is why just looking at the manual isn't enough. The wiring is more complex then what the diagrams can depict.

 

The commons are isolated also as they make up individual Circuits. You will have a mated common with each of the PM4's out puts.

 

I choosed to wire with the color codes to simplify things. We need to start using the terminology that Digitrax uses.

They use the term Rail A and Rail B. From this point on we'll use the example images. In this case rail A is white and Rail B is blue.

 

The PM4 takes 4 white and blue inputs and creates 4 protected outputs. Those 4 protected outputs each have their own common or what we will call the B rail. In my case the PM converts my B rail/blue/common wire to brown. When I see a brown wire I know it is a B rail wire that has short protection. My white wire is the A rail which is converted to 1 of 4 colors. yellow,orange,dark blue and voilet.

Each color has its specific brown wire or B rail.

 

 

This is not shown in the diagram. The diagram shows a single DCC unit where as the PM4 has 4 individual outputs of 4 pairs A and B rails.

 

Inobu

[gavino200]

As far as I can see, there is no need to add insulated joints within a block on the 'common rail' between subsections.

 

But there is also no reason not to add them. 

 

Adding insulated joiners between subsections, and using multiple feeders to the common rail at the same intervals as the control rail would.

 

1. Make trouble shooting easier (for now anyway)

2. Make it easier to use Kato type double wire for all my feeders (thereby keeping a degree of uniformity - I already have 20 of the suckers).

 

The downside is more work. No problem. I'm OCD and I know how to use it :)

[inobu]

If you want to use Katos feeder wires you can. Just establish which wire is the A rail and B rail and make sure it correlates to the inner and outer rail through out the layout.

 

Inobu

[gavino200]

Oh it's the sectional gap you are pointing out. It easier seen with the wired PM4 not the diagram. This is why just looking at the manual isn't enough. The wiring is more complex then what the diagrams can depict.

 

The commons are isolated also as they make up individual Circuits. You will have a mated common with each of the PM4's out puts.

 

I choosed to wire with the color codes to simplify things. We need to start using the terminology that Digitrax uses.

They use the term Rail A and Rail B. From this point on we'll use the example images. In this case rail A is white and Rail B is blue.

 

The PM4 takes 4 white and blue inputs and creates 4 protected outputs. Those 4 protected outputs each have their own common or what we will call the B rail. In my case the PM converts my B rail/blue/common wire to brown. When I see a brown wire I know it is a B rail wire that has short protection. My white wire is the A rail which is converted to 1 of 4 colors. yellow,orange,dark blue and voilet.

Each color has its specific brown wire or B rail.

 

 

This is not shown in the diagram. The diagram shows a single DCC unit where as the PM4 has 4 individual outputs of 4 pairs A and B rails.

 

Inobu

 

Agree. This is easier if we speak the same language.

 

Rail A = White = common rail

 

Rail B = Blue = control rail

 

Yes. The PM has four outputs. I just drew one for simplicity. 

 

I was planning on keeping a Dark wire/ light colored wire code for Rail A/ Rail B, and then shopping to see how many different color wire I could find for short protected wires for different districts. However, I'll think through your repeating color code with color coded cable jackets, and see if it will work for me. 

 

I also very much would like to know exactly what a wire is and does just from it's color.

Edited January 28, 2017 by gavino200

[gavino200]

If you want to use Katos feeder wires you can. Just establish which wire is the A rail and B rail and make sure it correlates to the inner and outer rail through out the layout.

 

Inobu

 

Yes, I plan on doing that. I just randomly placed my first one and kept then next 19 consistent. Blue is inside rail. White is outside rail. I'll either change this (can't see why I'd have to) or make the inside rails my Rail B.

[inobu]

As far as I can see, there is no need to add insulated joints within a block on the 'common rail' between subsections.

 

But there is also no reason not to add them. 

 

Adding insulated joiners between subsections, and using multiple feeders to the common rail at the same intervals as the control rail would.

 

1. Make trouble shooting easier (for now anyway)

2. Make it easier to use Kato type double wire for all my feeders (thereby keeping a degree of uniformity - I already have 20 of the suckers).

 

The downside is more work. No problem. I'm OCD and I know how to use it :)

The only reason would be if you foresee converting a block into a section.

 

For example. That long back straight away on your layout.

 

Today it's one block but in the future you wanted to break it up into 4 sections. Adding the isolators today makes it easy to do. Below the track the feeders will allow it.

 

Inobu

[gavino200]

I probably will make it into a few sections. I plan n a BDL for each track. Six sections will be used by two station platforms. I can divide the remainder of each track into 10 sections.

 

I'll draw up a zone map if I get a chance this evening. Off to go sledding now. 

 

I'll also try to make a complete wiring map, and think about my color code. I'll look online to see how many different colors of quality wire I can find first. Will post a picture when done.

 

 

BTW, for any beginner (like me), who was following this up until we started talking about block detection. Try reading this:

 

http://www.wiringfordcc.com/blockdet.htm

 

And this:

 

http://www.sumidacrossing.org/LayoutControl/TrainDetection/

Edited January 28, 2017 by gavino200

[inobu]

The colors help in troubleshooting and keeps order.

 

Based on your plan so far. Blue and white is your feeder wires.

If you were troubleshooting a switch problem you wouldn't look at a blue and white wire because it has nothing to do with switches. If you left the switches red and black then you could identify them easily.

 

In my case I setup my blocks as gray,white,green and red. Those are the block wiring to the feeders. When I'm above the layout and have a problem in zone 1 block 4. I know to look for Yellow belt wire and the red block wire.

 

Section 1-4 is Yellow,Orange,Blue,Violet. Block 1-4 Gray,White,Green,Red.

 

Section 4 block 2 is down. Under the table you would look for what wire.

 

Inobu