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Lets talk about wiring

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  • Member since
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  • From: East Central Florida
  • 480 posts
Posted by Onewolf on Monday, February 5, 2018 11:23 AM

A 50 foot run from the booster to the end of track is a pretty long run.  My longest track power bus runs are about 40 feet and I used 10ga THHN stranded for them. I used 12ga stranded for the shorter 'occupancy zone' track power bus lines and I use 22ga solid wire for track feeders.

Modeling an HO gauge freelance version of the Union Pacific Oregon Short Line and the Utah Railway around 1957 in a world where Pirates from the Great Salt Lake founded Ogden, UT.

- Photo album of layout construction -

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  • From: Mount Vernon WA
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Posted by skagitrailbird on Monday, February 5, 2018 11:22 AM

I believe 14g wire would be sufficient for a 45' bus but since you already have 12g go ahead and use it, recognizing that it will be a bit harder to work with due to its stiffness.

I would ditch the 16g & 18g wire for feeders. I think you will be mutch happier with 22g solid. Easier to solder to the rails and to the bus. Plus the rail connection will look mutch better.

Roger Johnson
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Posted by Paul3 on Monday, February 5, 2018 11:16 AM

SpaceMouse,
Twisted data cables (like CAT/5) are twisted in pairs for self-shielding properties.  They can resist outside interference better if they twist the matched pairs together.

LocoNet, however, is flat data cable.  I've talked with Digitrax about this, and they recommend not using twisted pairs for LocoNet cables.  Why?  I dunno, but they know their system better than I do.

One good thing about bigger wire for DCC bus use is that you have less voltage drop and a therefore a better, clearer digital signal.

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Posted by UNCLEBUTCH on Monday, February 5, 2018 11:05 AM

My last layout didn't have a buss,Feeders { reclaimed 24ga}  were droped down and pigtailed , a jumper went to another pigtail,and so on. Never a problem.

I wanted to clean it up,ran a 12ga buss,cause I had some on hand. 12ga is a bear to work with. On the new layout I decided to spend the money on 14ga bus,way better, and reused the reclaimed 24ga feeders. Thats on just over 50ft of track not counting the yard and sidings.

Somtimes you got to justify not spending money agaist stress

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Posted by Overmod on Monday, February 5, 2018 10:59 AM

Lone Wolf and Santa Fe
Twisted pair wiring came from the telephone company so that in a bundle of dozens of wires the pair of wires for each individual phone line stayed together and didn’t get lost in the crowd.

All this time I thought twisted-pair coupling cut down on crosstalk between the pairs.  Twisted-pair becomes essential in high-data-rate applications like Ethernet cabling.

If you are feeding relatively unmodulated DC down a 'legacy' length of twisted-pair, the value of the twisted-pairing probably defaults to what he said, useful color coding to pick out the circuit at the other end.  If you are feeding even relatively slowly modulated intelligence over the DC, maintaining the twist right up to any connectors will still have value.

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Posted by SeeYou190 on Monday, February 5, 2018 10:51 AM

SpaceMouse
1) What is the advantages or disadvantages of solid wires vs twisted wires?

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The biggest advantage of stranded wire it that it is more flexible and easy to work with.

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Secondary advantage: it will still work just fine if a few of the conductor strands break. It you use solid wire, and it breaks, you are done.

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SpaceMouse
2) Why are wires transmitting data twisted? I know they suggest twisting bus wires on DCC layouts, but from what I seen in reality on YouTube, the twisting is half-assed (and mostly, I think) to say they did it.

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This is so one conductor does not induce a current into the other one that is run parallel. Not a big deal in 12 volt track wiring, but with DCC this becomes a concern. The little "1s" and "0s" that make up the data packets can become corrupted. If the data pack is unreadable the intended receiver will ignore it.

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This is very true with heavy equipment that uses SAE 1587/1708, SAE J1939 or CAN/BUS for cummincation between devices. It is amazing how similar the controls for cranes are to the controls for model trains.

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Twisting data pairs is very important. Neatness does not actually count for much.

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-Kevin

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Living the dream.

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Posted by mbinsewi on Monday, February 5, 2018 10:46 AM

SpaceMouse
1) What is the advantages or disadvantages of solid wires vs twisted wires?

I get the solid wire, but by "twisted", do you mean, do you mean stranded wire, or runs of solid wire twisted together?

My L shaped dog bone continuous run is 50', I used 14 ga. solid wire, red and black, for the main bus,  and for the feeders, I used 22 ga. solid wire.  I did twist the red and black bus wire together, just make it a little more confined, and then seperated them were I soldered the feeders.

I would think that the 12 ga. solid wire, the house wiring, would be fine for the bus.  I'm thinking the 16 or 18 ga., might be a little big for the feeders, but I don't know what your plan is for attaching the feeders to the track.

That's why I used the 22 ga.  Just a smaller wire to deal with, and hide, as I soldered mine to the outside of the rail.

As far as stranded wire vs. solid, the stranded is more flexible.  I think the solid wire is better for bus and feeders.

Mike.

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Posted by SpaceMouse on Monday, February 5, 2018 10:41 AM

Lone Wolf and Santa Fe
Bigger wire is stiffer and harder to work with. Also it costs more.

Thanks. Thing is, I already have the wire so there is no cost. 

So if my bus is 45 ft long, what guage wire would you suggest?

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

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Posted by Lone Wolf and Santa Fe on Monday, February 5, 2018 10:37 AM

SpaceMouse

 

 
Lone Wolf and Santa Fe
Therefor you don't need #12 wire.

 

It's not a matter of need but a matter of got. Is there a disavantage in going with too big a wire?

 

Bigger wire is stiffer and harder to work with. Also it costs more.

Modeling a fictional version of California set in the 1990s Lone Wolf and Santa Fe Railroad
  • Member since
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Posted by SpaceMouse on Monday, February 5, 2018 10:32 AM

Lone Wolf and Santa Fe
Therefor you don't need #12 wire.

It's not a matter of need but a matter of got. Is there a disavantage in going with too big a wire?

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

  • Member since
    January 2015
  • From: Southern California
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Posted by Lone Wolf and Santa Fe on Monday, February 5, 2018 10:26 AM

110 volt AC
15 amps = #14 wire
20 amps = #12 wire
30 amps = #10 wire

The breaker size is determined by the wire size. If the wire is smaller than the breaker size then the wire will burn before the breaker trips.

Amps times volts = watts

15 amps X 110 volts = 1650 watts

The power from your transformer is DC for starters and it is not 110 volts. It is usually around 12 volts. Therefor you don't need #12 wire.

Twisted pair wiring came from the telephone company so that in a bundle of dozens of wires the pair of wires for each individual phone line stayed together and didn’t get lost in the crowd.

Modeling a fictional version of California set in the 1990s Lone Wolf and Santa Fe Railroad
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Lets talk about wiring
Posted by SpaceMouse on Monday, February 5, 2018 10:15 AM

Let's talk about wiring. I figure I'm going to have a lot of questions. So let's start with the little I know about it. Feel free to correct me here.

1) If you are drawing a lot of amps you have to have heavier guage wire. Power tools such as worm-drive saws (draw 13-15 amps depending on manufacturer) need at least 12 guage wire to run 100 feet on a power cord or they suffer from voltage drop and can burn up. They use twisted wire.

2) The same principle applies to house wiring. If you are on a 20 amp breaker you need 10 guage wire. On a 15 amp breaker you use 12 guage wire. Both of these are solid core wire.

3) Data--phones and computer--is trasmitted over some pretty great distances using thin 24 guage solid core wire. For some reason, they twist it. That it is except LocoNet wiring which is a flat ribbon.

4) The smaller the wire, the easier it is to solder to the track and make it look good.

5) Soldering thin wire directly to a solid 12 guage bus isn't as easy as it should be.

 

I want to understand the why of things so I can make decisions about my layout. For instance I have a sufficient length of 12 guage romex residential wire, and a lot of Cat 5--like half a box (250 ft or so 8 strand twisted pairs). I also have some short pieces of 16 or 18 guage solid core wire in red and green--probably enough to do the feeders. 

First 2 questions:

1) What is the advantages or disadvantages of solid wires vs twisted wires?

2) Why are wires transmitting data twisted? I know they suggest twisting bus wires on DCC layouts, but from what I seen in reality on YouTube, the twisting is half-assed (and mostly, I think) to say they did it. 

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

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