Wire Size Tech Tip

All about wire and cable:


 What size, how many conductor, and what kind of wire should I use on my layout?

Wire size:

Wire is graded by gauge which basically means how thick the conductors are. The smaller the “gauge” the larger the wire.  Number 4 or no 6 wires for example are used to bring into your house to feed the circuit panel in your house. 50-gauge wire was used frequently inside of computers to transfer data.  Lionel would give you a small length of 22 gauge to power your tracks. For a run of a couple of feet that was ok. For longer runs bad idea. 

 Note:  Wire has built in resistance usually measured by OHMS of resistance per foot. The smaller the wire the more resistance. What that means is the more feet you have the higher the resistance the more power loss you will have. The larger the wire (the gauge of the wire) the less the loss. This is a matter of mathematical computation, so let’s just use the kiss system.

To run trains:  For runs up to 60 feet’ 18 gauge is fine. For longer runs go to 16.

For switches, rcs tracks, toys etc: For runs of 8’ or less 22 gauge is ok. We have used this size for controllers up to 8’ runs.  only problem is wire is not very thick and is hard to work with.  This year (2023) we have received new cables specifically made for us,  and is 20 gauge. Much heavier than 22 gauge. This new wire works great for switches rcs controls, lights etc up to 60’ For short runs (under 10’) will work to power trains also.

 For LED’s 50 gauge will work but is a pain. Suggest 22 gauge which is also ok for lights.

For spurs power taps etc 18 again is a good choice..

How many conductors?  Logic says just run the number of conductors you absolutely need to power whatever or is it. Our train stuff always seem to have babies,. which require wiring. So why not run an extra wire as a just in caser for down the road?  I like 4 conductor cables.

What kind of wire?

First, always use stranded wires not solid. Stranded wires (especially for AC) will handle more power, and are much easier to work with. Plus they don’t break. The more individual wires in any one wire the better. The wires we now have made for us have extremely fine wires, but lots of them. Makes the whole cable much more flexible, solders easier, and handles more current then normal wires.

Pure copper or copper clad over aluminum?

Pure copper has less resistance, handles data better, and solders better.

True, but is 5 times more expensive, If you are wiring a house, or sending data more than 75 feet absolutely use pure copper. For our applications on our layouts it is a total waste of money. We use exclusively copper clad wires and they work just fine. The actual differences would be completely meaningless.. For soldering, use a 600-degree tip and even the smallest gauge wires you will have no difficulty. Useless info power companies now use all aluminum wires except for the big towers which they add a steel core for strength for long runs. Our current cables do have a tiny tiny center of aluminum, so small, it is very hard to see. Them being so small and using so many wires per cable, works out great.

Oh a word about solder.  Use only Kester 60/40 66 rosin core solder. It is up to twice as expensive as other solders and believe me is well worth it. We use the .062 size exclusively, but some folks like the thinner gauge .031.I’ve tried cheaper solders and the grief ain’t worth the price difference. Remember this is a lead base solder, so hold your breath when melting it. We use very strong exhaust fans on our workstations.  Yeah I know, old school.

Last tip:  use fork connectors to attach wires if possible. Don’t have to worry bout strands shorting out.