Time to wire up the layout. I’m going with 14 guage wire - but should I use solid or stranded? Is one better than the other? If so, please explain why.
Solid or stranded? That’s the question.
Jim
This has been kicked around quite a bit in the model railroad forum. Bottom line is that the differences are too small to worry about in model railroading. Some people prefer stranded because it is more flexible and easier to bend while others like solid because there is only one wire to solder or attach to terminals. Use which ever one you prefer to work with.
Enjoy
Paul
[#ditto]
I use both. Cheapest at the time of procurement is my guide.[:)]
Thanks, guys. No real difference between solid and stranded, huh?
Jim
I also use both. If it is stranded, then I tin the ends so it becomes solid.
Only stranded for me , but I use all kinds of crimp style connectors, ends, and splices.
I do intend to crimp on connectors at the ends.
Jim
It is often alleged that stranded wire has lower resistance because it defeats the skin effect.
The skin effect is a phenomenon which confines the current to the outer surface of a conductor. It increases with frequency and with conductivity. At 60 hertz in copper, the skin depth, the depth into the conductor at which the current decreases to 37 percent (1/e) is about 8.5 millimeters. When the skin depth becomes comparable to the wire radius, the effect on wire resistance becomes extremely small. The diameter of 12 AWG wire is only 2 millimeters, which would make any effect virtually impossible to measure, much less notice when running trains.
Ordinary stranded wire does little to reduce the skin effect in any case. There is a special kind of stranded wire, called litz wire, which is effective in reducing the skin effect. The litz-wire strands are insulated individually and woven together in a way that puts each strand near the surface and the center of the bundle at various places along the wire. The strands of ordinary wire are not insulated from each other and are not woven. So, even if there were a skin effect at the frequencies and wire sizes that we use, stranded wire would not help.
The only sensible consideration is convenience in working with the wire.
Stranded!
Far less likely to break and much easier to fasten effectively(solder or crimp). One reason stranded is used in appliances,machine tools and fixtures.
I went with the 16 gauge stranded paired white lamp cord.
Got it at an Army Navy store.
300 feet for $20.00.
I use a magic marker on one side to decide which one is the hot lead.
laz57
I use 14 ga. stranded for bus wires, then solid wire of various gauges for feeder wire to track or accessories.
George, feel the edges of your lamp cord. One should be smooth; the other should have an almost invisible ridge or ridges. That is the “identified conductor” and the one that is normally grounded. Even if your wiring is already in place, knowing this could be useful for identifying which wire is which at both ends for repairs, alterations, and additions.
Thanks BOB, I didn’t know this.
laz57
According to code all paired conductors must be identified. i.e. lamp cord, romex, etc.
Stranded or solid?
Stranded for awg #16 or larger,
Solid for awg #18 or smaller.
Reasons are ease of working with and ease of termination!
If you still don’t know buy a little (or visit a home construction site for scraps) and try each one out and see for yourself.
Either stranded or solid copper wire will serve well for wiring a train layout. Each, however, has benefits and disadvantages:
Stranded is easier to bend and route around. Solid is easier to poke through holes.
Solid is easier to form in a loop to go around a transformer post. Stranded should be “tinned” so it is solid before forming the loop. Wire should ALWAYS go around a post CLOCKWISE; otherwise, tightening the post will force the wire away from the post.
If you twist two or more solid wires together, they will stay. Stranded wires twisted together will come apart. Solder or a wire nut will help both. Twisting solid and stranded wires together usually doesn’t hold and should be soldered.
A solid wire nicked during stripping will break. A stranded wire may lose a strand or so, but will not fail completely. Only use a stripper that has a formed hole! Never use one of those “one size fits all” types: they will nick the wire every time. Even check the hole to use. Strippers are different for stranded and solid wire. In general, use the next hole up for stranded. An automatic stripper will save a lot of time. To check for nicks, strip a half inch, then strip another half inch. Look for nicks where the first strip was made. Use the next hole size up if the wire is nicked or any strands are cut.
House wire is cheap. “Stranded” house wire has only a few strands, so is sort of a compromise between solid and stranded. Smallest size available is #14.
Use “hook up” wire otherwise. It has the smallest insulation. “Appliance” wire has thicker insulation, so wire bundles will be larger.
I use #10 solid, bare copper “grounding” wire for “track common/outside rail” run under the track areas. Short #16 wires are connected to the outside rail and soldered to the bare wire. A #10 or #8 wire is not overkill for “Track Common.” It must carry the sum of the current for all engines and anything else connected to "track
Good advice John,
I would however add that back twisting (holding the wire in your left hand and tightly twisting the strands toward you with the right hand) the stranded wire for terminals and always using wire nuts on splices will eliminate the need for solder.
Bob Nelson’s description of conductor identification on paired cords also applies for the secondary [low voltage output] cord on Lionel PowerHouse transformers. This knowledge is only useful if you cut the plugs off [as I do] and solder on spade lugs for connection to terminal strips used as distribution junctions or wired to TPCs, for paralleling,etc.
The ribbed or ridge “teltale” along one of the conductors in the PoHo cord’s pair is the Common conductor. I use white code for the Common on my RR so I wrap a piece of white plastic tape around the shrink tube on the barrel of the soldered spade lug of the ribbed/Common conductor.
Solid is definitely better than stranded. Fact, that’s what my house is wired with.
However, ensure that there will be no twisting motion involved as if you continually bend solid, it will break more quickly than stranded. The smaller gauge solid, like phone cable, a really the culprits in this respect.
So, it all depends on how you are going to use the wire.
I’m debating whether or not to go solid or stranded in rail-to-rail jumpers, where movement, due to heat/cold differentiation, would be slight.
Any opins on this are welcome.
David, I am just wondering if you could elaborate on your statement that, “Solid is definitely better than stranded.” Seems lots of people feel it does not matter if one uses stranded or solid, but you definitely go with solid. Can you explain some of the reasons that solid is better? Thanks!
Reading and PA RR,
“It should be common-sense knowledge that liquids flow through large-diameter pipes easier than they do through small-diameter pipes (if you would like a practical illustration, try drinking a liquid through straws of different diameters).”
From: http://www.faqs.org/docs/electric/DC/DC_12.html
Other sites reviewed agree, as well as my neighbor, who is a telecommunications specialist w/SAIC, working for military. He helped me wire my house.
The #1 reason for buying stranded is FLEXIBILITY. If you’re wire is going to be continually moved, then that’s the way.
Some say that since stranded has more surface area, it should be able to allow more electrons to pass. However, the inner strands do not have as much current as the outermost section of the strands, and much of the stranded wire is just air or dead space, meaning that you need a thicker stranded wire to carry as much current as a thinner solid wire.
But whether you have 14 ga stranded or solid, the effect most likely will be so minor in model RR operations as to be meaningless.
If your layout is a large one, I’d recommend going with 12 gauge. Even some large HO layouts use 12 gauge for the bus wiring.
There are several other advantages to solid. For one, it is usually less expensive than stranded (Romex, for instance), b/c it is so widely used in households (in Virginia anyway).
It is easier to crimp (or pigtail) solid wire and standardized and inexpensive fasteners are made for connecting these solid wires (the multicolored plastic fasteners found in your outlet box).