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Wiring

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Wiring
Posted by jacon12 on Wednesday, July 5, 2006 7:23 AM
I've been told that it would be best to wire my layout in blocks, even though I'm using dcc, in the event there is a problem it would be easier to find. By 'blocks' I think the guy meant to divide the layout into sections, running wires to maybe 3 different areas from a centrally located terminal block to which the dcc controls are hooked. I think maybe it would be best to place this terminal box beneath section B..

and then run the two bus wires down that section, over to section A following the track and terminate the wires on the backside. The next set of wires would be for table B, and the third set for table C. Is that a bit of overkill and maybe just have it divided into 2 sections, or just run the wiring in one big block?
How would you do this?
Jarrell
 HO Scale DCC Modeler of 1950, give or take 30 years.
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Posted by Adelie on Wednesday, July 5, 2006 8:05 AM
Jarrell, it might be overkill but there is nothing wrong with it.

If you are dividing the layout into double-gapped blocks (power districts in DCC lingo), you probably want to wire each section through a power management module. That way a short in one section does not bring the entire operation to a grinding halt.

Just looking at it on the screen and not knowing what your normal operations will be, I would make the peninsula in C it's own district since that is where your yard is located. Yards = turnouts = possible points of "annoyance and displeasure." You could certainly run this as one power district, but I tend to design these things in honor of my friend and frequent visitor, Murphy.

The other kind of block is a detection section, which is a single-gapped block. Those can be done fairly easily up front and everything wired to the normal bus. Later, if you decide you want block occupancy detection for something such as signals, you simply run the feeders from the gapped rail side through a block occupancy detectors. It provides no short protection and no autoreversing (I don't see any reverse loops on this plan, so that is moot), but it will detect locomotives or cars fitted with resistor wheelsets. Doing that now costs you a few insulated joiners or gaps, but gives you some flexibility down the road.

- Mark

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Posted by jacon12 on Wednesday, July 5, 2006 8:21 AM
QUOTE: Originally posted by Adelie

Jarrell, it might be overkill but there is nothing wrong with it.

If you are dividing the layout into double-gapped blocks (power districts in DCC lingo), you probably want to wire each section through a power management module. That way a short in one section does not bring the entire operation to a grinding halt.

Just looking at it on the screen and not knowing what your normal operations will be, I would make the peninsula in C it's own district since that is where your yard is located. Yards = turnouts = possible points of "annoyance and displeasure." You could certainly run this as one power district, but I tend to design these things in honor of my friend and frequent visitor, Murphy.

The other kind of block is a detection section, which is a single-gapped block. Those can be done fairly easily up front and everything wired to the normal bus. Later, if you decide you want block occupancy detection for something such as signals, you simply run the feeders from the gapped rail side through a block occupancy detectors. It provides no short protection and no autoreversing (I don't see any reverse loops on this plan, so that is moot), but it will detect locomotives or cars fitted with resistor wheelsets. Doing that now costs you a few insulated joiners or gaps, but gives you some flexibility down the road.



I appreciate you taking the time to tell me this. One thing is for sure from your answer, I need to do a LOT more reading up on this so that I understand things like block occupancy detection, double gapped blocks and detection sections. In other words, like I used to tell photography students, Ya gotta learn the basics!!
It's comforting to know that Murphy is also a buddy of yours, God knows he spends enough time around here.
Jarrell
 HO Scale DCC Modeler of 1950, give or take 30 years.
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Posted by selector on Wednesday, July 5, 2006 10:13 AM
Jarrell, I just did this, and it just takes some early diagramming to get it right. Use main buses as you suggest, then have a sub-bus come off each bus. So, diagrammatically, each bus/sub-bus would look like an H on its side, with a short feeder pair of wires between them. I would very strongly urge you to use the #1156 tail light short detection/protection method used by Joe Fugate. I did, and giggle every time it does its "thing" for me.

The H is really paired wires on all segments. You solder one bulb onto one of the feeders by cutting it and soldering the far end (going on to the sub-bus) on the side of the bulb metal body, while the close end (closest to the main bus) is soldered to the tip at the base of the bulb. That simple.

From the sub-bus main wires, which follow the tracks more closely than the main will need to, solder feeders to your rails, above.

The bulbs are cheap, some are meant to last forever (if their ads on the packages can be accepted), and the setup works like a hot da**.
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Posted by jacon12 on Wednesday, July 5, 2006 10:29 AM
Thanks Crandell for the help. I'll try to get my brain wrapped around busses and sub busess... :) I need to read Joes tute on using the bulbs again, it sounds like a good idea!
Jarrell
 HO Scale DCC Modeler of 1950, give or take 30 years.
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Posted by jacon12 on Wednesday, July 5, 2006 10:32 AM
Another wiring question that is simpler to answer.
Is there a certain length that you should try to keep feeder wires under, in other words... say... 6 inches? Is shorter better than long? Is there a noticeable difference, in power delivered to the track, if they're maybe 12 inches long?
Jarrell
 HO Scale DCC Modeler of 1950, give or take 30 years.
  • Member since
    February 2005
  • From: Vancouver Island, BC
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Posted by selector on Wednesday, July 5, 2006 12:42 PM
As you know, or surely can tell, short is good....everywhere. So, for the sake of overall penny pinching, keep your heavier 12-14 gauge main bus as short as you can get away with. Coming off it, in discrete sections what you want to isolate using the single bulb, your 18 gauge sub bus will likely be short runs paralleling the main line. Again, those individual wires need be no longer than the district or block you are designing, and could be shorter with the feeders covering the extra distances to the extremes of each block/district.

To respond directly, your feeders will have to span the gap from your bus (if you elect to forego the sub) to your rails, or from the sub to your rails....no matter what.

Here is what I did: I ran the heavy wires only as far as I needed to, and kept them close to the front of my benchwork. At certain, predetermined, points along that close heavier wire bus, I dropped a feeder to a sub that paralleled the main loop (not the spurs and yard, necessarily) so that no one set of feeders to the rails from it would have to be longer than about 18". You can appreciate that on a flat bench with foam or plywood on it, the feeders could get as short as 5-7" between the closely tucked sub and the rails. On mine, with open grid frame and risers with spline over them, the feeders have to be longer to reach from the frame-bound sub up past the risers and into the splines to meet the rails. Some of my feeders, all about 22 gauge, are in the order of 20".

I hope that is a help. Bus with bulbed feeder to a segmented sub. The sub sends power to a gapped section so that the bulb can tell you which section of your system is experiencing the short. Past the bulb is the sub, itself, only long enough to allow short feeders up to your rails...in that section.

Joe's clinic is straightforward. Just keep your wires colour coded and oriented, inner rail/outer rail, and you will be fine.
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Posted by claycts on Wednesday, July 5, 2006 3:12 PM
This may help you.
I installed a RAMP METER from Tony's to get true RMS at each panel and we have one that is portabel for voltage loss (another story).
With this in mind, looking at your plan, you would run #12 awg STRANDED wire from the central panel to the A in one direction and to C in the other direction. Get some EURO TERMINAL BLOCKS for Radio Shack and Cut them apart to make them into (2) segments (red/black).
Terminate your bus with these so you can ADD ON if you have to.
Running #12 awg bus you can use #18 to #22 SOLID from the rails DOWN to the bus. Ours are from 12 to 18" max with most around 9" long.
Put a feeder (drop from rails) every 2 sections of Flex track (6 feet max).
we did this and have No problem (this is 750 feet of track we are powering).
The bus should Mirror the MAIN LINE ONLY DO NOT have to mirror the sidings or each yard track. Remeber to keep your RED AND BLACK rails in PHASE red to red, black to black.
I am using all Digitrax EXCEPT for the district Breakers I use Tony's PSfour (6 of them).
If you already know this then forgive the following information.
DO NOT confuse a Circuit Breaker for a Booster/Breaker. A Booster is worth 5 amps of power a Circuit Breaker is worth ZERO amps of power. Some people would read my system as 24 breakers (6x4) as 120 amps of track power that is not true we have (6) 5 amp boosters with (1) PSFOUR off each Booster giving use 30 amps of power. 25 amps for trains a 5 amps tp handle 116 Tortise units and logic uniits.
Take Care
George P.
Taking another look at your plan. Segment "C" would be your HEAVY USE segment (yard and such) the yard is ONE disrtict. Isolate that track. In the same segment you would then have a seperate district coming into the yard and another district on the other side of the yard. This way a short in the yard would not shut down the layout.
What are you going to use for turnouts? Power for them?
We ran a #14awg Bus for just the turnouts with its own booster. Remeber you must consider how many trains you will run at one time to make sure you have enough power for that AND the turnouts.
Take Care George Pavlisko Driving Race cars and working on HO trains More fun than I can stand!!!
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Posted by Anonymous on Wednesday, July 5, 2006 5:18 PM
Two recommendations (in addition to those above):

Get a good, recent RR wiring book. Several are available, including from Kalmbach. Some of those are listed at: http://kalmbachcatalog.stores.yahoo.net/model-railroading-books-wiring-electronics.html

Take a look at: http://www.wiringfordcc.com/
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Posted by jacon12 on Wednesday, July 5, 2006 7:15 PM
Thanks for all the help, fellas. I have a lot to learn and need all the help I can get.. :) A friend has loaned me a book on wiring model railroads and it looks as though it dates from about the beginnings of dcc, at best. But, there's probably a lot of information in it that'll be helpful even though it's primarily a dc book.
Time to get reading.
Jarrell
 HO Scale DCC Modeler of 1950, give or take 30 years.
  • Member since
    May 2003
  • From: Santa Fe, NM
  • 1,169 posts
Posted by Adelie on Wednesday, July 5, 2006 7:22 PM
Jarrell, try playing around on Digitrax's web site in the various manuals. For instance, there is a diagram for wiring detection sections on the instructions for the BDL-168 (block occupancy detector, under detection and signals). Some of those diagrams say more in a page than you can learn in a chapter of a book.

It is not as intimidating as it sounds.

- Mark

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