# Wire Gauge?



## monsterhunter (May 25, 2008)

Howdy. 
Can anyone tell me what size wire is best for my code 332 layout? Does length of track determine how large the wire should be? 
Thanks.


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## Trains (Jan 2, 2008)

I used the low voltage outdoor wire for lights. Worked great and no need for plastic pipe. I think it comes in 14 and 12 gauge.


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## Bill Swindell (Jan 2, 2008)

The distance from your power supply and the current draw determines the proper wire gauge. In general, the bigger, the better. Our HO club used 10 gauge wire for track feeders. You might consider using at least 12 gauge wire.


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## altterrain (Jan 2, 2008)

10 gauge for HO??? Are you running 50 locos at a time? 
Most of your household wiring is 12 gauge for 120volt 15 amp circuits. Some of that is pretty long runs from the circuit box. Any larger gauge is reserved for large appliances. 
I use 16 ga. low voltage landscape light wire for short feeders (less than about 30 feet) and 14 gauge for longer runs. Some use 12 ga. but its over kill in my opinion. 

-Brian


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## Bill Swindell (Jan 2, 2008)

On our HO layout, the maximum difference in voltage drop from one end of the layout to the other is 1/2 volt at full current. The layout is 30' x 50' and the throttles can put out 5 amps. We have run as many as 14 locomotives on one train.


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## Dan Pierce (Jan 2, 2008)

It is better to run 2 pairs or more of wire (feeders) from the power pack to the rails. This will give the least amount of power losses if using rail clamps and conductive grease. 

A pair of 14 guage wires are much better than a single 12 guage and is close to using a 10 guage wire. 

Outdoor low voltage wiring has one side ribbed and the other smooth so you can hook it up properly and is very flexible.


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## astrayelmgod (Jan 2, 2008)

Bill -- 

14 locomotives on one train? How many cars was it pulling? What sort of grades do you have?


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## ohioriverrailway (Jan 2, 2008)

Seems to me that #14 works quite well unless you have grades and multiple engine consists. I ran the feeders right along with the track in a loop and tapped in every 15 or 20 feet or so, excpet on the downgrade (I run counterclockwise only) and it works fine. The trolley wire is #22 NS and it only needs to be fed every 10 feet or so. We're not talking about all that much current draw in most cases.


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## Greg Elmassian (Jan 3, 2008)

Monsterhunter: (by the way, what's your real name?) 

You have not mentioned: 

type of track (brass, SS, aluminum, NS) 
type of joiners (stock, rail clamps, etd.) 
type and number of locos you will use eventually 
length of trains 
grades 
whether you will run analog power, or some type of control that uses a constant track power. 

All of these items will impact your choice. 

For example, I run: 
SS rail 
Split jaw SS rail clamps 
Lots of locos MU'd / doubleheaded 
up to 3.4% grade 
DCC (constant track power) 
long trains (20-40 cars) 

with all that, I needed 10 gauge feeders, and feed points every 20-30 feet to minimize voltage drop (I can get pretty close to 10 amps on a single train). 

Regards, Greg


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## Madman (Jan 5, 2008)

Being in the construction business, I have access to unwanted damaged extension cords. Since the stranded wire used to manufacture them is finer than stranded house wire, it is more flexible. And they are usually UV resistant. It's 

an inexpensive source of wire.


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## Greg Elmassian (Jan 3, 2008)

I've had a somewhat negative experience with stranded wire outdoors. 

I have to preface this with the following, I run DCC, the track power is always on, and the track gets "watered" pretty much daily. 

Stranded wire, being thinner than solid, will corrode more easily, I've had some stranded #10 wire just dissolve where it was exposed to the elements. Very fine wire would make it dissolve more quickly. 

I recommend solid wire where it is exposed, then connect to stranded feeder when "water tight". 

Regards, Greg


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## altterrain (Jan 2, 2008)

Posted By Greg Elmassian on 05/27/2008 9:22 PM 
I've had a somewhat negative experience with stranded wire outdoors. 

I have to preface this with the following, I run DCC, the track power is always on, and the track gets "watered" pretty much daily. 

Stranded wire, being thinner than solid, will corrode more easily, I've had some stranded #10 wire just dissolve where it was exposed to the elements. Very fine wire would make it dissolve more quickly. 

I recommend solid wire where it is exposed, then connect to stranded feeder when "water tight". 

Regards, Greg




I would guess that would depend on the type of layout you have. If you have a "garden layout" I would stick with the stranded wire. I have yet to see any manufacturer of low voltage outdoor landscape lighting recommend or sell a solid wire. 

-Brian


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## stanman (Jan 4, 2008)

FYI, one of the functions of my _Handy Converter_ program helps you determine the best wire size for your layout. It lets you enter the length of your wiring run and load current (amps), and tells you what the voltage drop would be. 

A video demo of this function can be seen at  Wiring Demo


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## Greg Elmassian (Jan 3, 2008)

Brian, I don't think there is such a thing as solid stranded wire. I mentioned solid wire. 

Landscape wire is stranded to allow it to be buried easily and conform to the ground, etc. Also the connectors most used rely in piercing the insulation to contact the wire, which only work on stranded wire, or there are silicon-filled wire nuts, and twisting large gauge solid wire would take more effort. 

But, I'm concentrating on just exposed wire where you connect it to the rails. I use a solid piece, crimped in a ring terminal, then connect it to the stranded wire and waterprooof the connection. 

If I have stranded wire in the open, water gets into it (Between the strands) and works its way inside, eventually causing corrosion and wire breakage. 

Regards, Greg


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## pimanjc (Jan 2, 2008)

All the discussion of type, gauge, etc., is relevant and informative. However, for me, the criteria of availability, cost, adequate gauge, and durability outside were my concerns. I chose to use 12g. Malibu outdoor lighting wire for both the lights and the track feeder web. It is reasonably priced, easily available at Walmart, Ace, and other locations, 12g. should handle any load on the layout, and it is made to stay outside on/in the ground. 

JimC.


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## Greg Elmassian (Jan 3, 2008)

Actually my friend, 12 gauge will not handle the load on my layout, I often run over 5 amps on a train, and will be topping 7-8 soon. My layout runs multiple locos, so is probably not typical. 

Also, I use stranded 10 gauge, it was easy to feed through conduit, and cheaper per foot than malibu, even 12 gauge, though 10 gauge outdoor lighting wire is available. I will be changing to solid, because of the easier corrosion on stranded wire above ground. 

The 10 gauge wire is very cheap, since it's what they wire houses with. 

So, it is very reasonably priced, very easily available, and it does handle ANY load I have. 

So, since there has been no reply to all the questions I posed above, it's really impossible to tell how big is big enough for the originator of the thread. 

Overkill? For some, maybe, for me, necessary. 

Regards, Greg


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## Madman (Jan 5, 2008)

Greg, I beg to differ with you on the 10 gauge wire. Houses usually are wired with 14 gauge for 15 amp circuits and 12 gauge for twenty amp 

circuits. 10 gauge might be used in some instances for certain appliances etc, but never wholsale throughout the house. I take it you are talking 

about common electrical circuits. 

Also, 12 gauge wire is good for up to twenty amps, so your 7-8 amps should more than flow freely though it.


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## Greg Elmassian (Jan 3, 2008)

Sorry Dan, I meant to say I used the type of wire that can be used in a house, i.e. the thinner insulation that you will find on 14-10 gauge. 

The point I was trying to make is you can use the thinner insulation type of wire in conduit, and get more wire in the conduit / have easier "pulls". 

(you would find this wire on some 220 circuits) 

In terms of amps, I will differ with you: it's not the max amp rating, it's the loss in the wire you want to think about. 

So, if you are just running a few amps and a few feet, then it's no big deal. 

Now run 50-100 feet AND close to 10 amps, and your 12 gauge will have too much voltage loss. 

So, length and current need to be considered, the loss in wire is controlled by these factors. 


Regards, Greg 

(note the original poster still has not responded to any questions of how long, how many locos, etc. so we have no idea what the current requirements are, so it is impossible to recommend any gauge wire now)


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## Madman (Jan 5, 2008)

True. The wire length will determine how much of a load you can place on it. 

As for stranded wire; I was once told by the electrician on the job, that stranded wire has less resistance than solid. The theory was that 

electrons flow on the surface of each conductor. Since stranded wire has more surface area than solid wire, there would be less resistance. Others 

have argued the point. 

What's your opinion on this theory?


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## stanman (Jan 4, 2008)

Posted By Madman on 06/10/2008 7:33 PM
I was once told by the electrician on the job, that stranded wire has less resistance than solid.

From the research I did when I put a wire size calculator in the Handy Converter program, the opposite may be true. One source that I used gave this example: "... a 12 AWG solid copper wire has a resistance of about 5.21 ohm/km compared to 5.32 ohm/km for a 12 AWG stranded wire." 

Note that this is only a 2% difference, and from a practical standpoint is probably lost somewhere within all of the other variables in wiring a layout, e.g., in free air, in conduit, buried, type of insulation...


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## Greg Elmassian (Jan 3, 2008)

Well, I just happen to know the answer, from my background in what I learned in college and actual measurements. 

First, though, there is something you might not know, I did not until I did some investigation on stranded wire: typically the overall diameter of the wire (without insulation) is different between stranded and solid. IT makes sense that stranded is larger in diameter, because the air space between the conductors makes less copper per diameter. You can look up the diameters of standard stranded wires (because the number of strands can vary) on the Internet. 

The idea it to give you the same amount of copper per foot whether it's solid or stranded. 

There are situations where electrons are so "active" that they repel each other, and will migrate to the surface of a single conductor. 

It turns out that these situations require frequencies WAY above anything that electrician ever encountered in his work, in the 10s of megahertz. 

Also the strands would have to be individually insulated to give you more surface, the strands touching each other would negate some of the effect. 

So, for what we are are dealing with in trains, there is no difference. 

I have stranded wire, since it was easier to handle, but will go to solid because the thinner conductors are more susceptable to the elements. 

Regards, Greg 

Some reading on skin effect: http://forums.mikeholt.com/archive/index.php/t-82126.html 

And, the actual formula to calculate resistance based on wire diameter and frequency: http://www.allaboutcircuits.com/vol_2/chpt_3/6.html


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## Madman (Jan 5, 2008)

Greg and Stan, very interesting. 

Something else came to mind as I was reading your posts. When my son was into speaker systems etc., he used to buy "Monster Cable". I asked him if 

zip cord or lamp cord as I know it wouldn't do the smae job. He insisted that monster cable allowed better sound at the speakers.


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## Greg Elmassian (Jan 3, 2008)

Yes, the main part of "monster" was the much larger gauge. These cables are often made of many fine strands, mainly for flexibility, but also there is greater surface area, so it COULD help sound a bit, if you wanted the last 1% improvement (from the larger surface area, the larger cable is definitely a no brainer in helping). 

I had speaker cable that was the diameter of your little finger. If you have 3 ohm speakers and run 600 watts into them, then ANY resistance can result in significant power loss... and loss of fidelity, mostly in the bass area... 

Monster cable now is a brand of many different "high end" cables... 

Regards, Greg


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