Wire...stranded vs solid?

I like stranded it is more flexible & easier to work with & if you are crimping solid will not work very good.

Ken M

I was going to use all stranded, more flexible and easier to work with (just personal preference here). I couldn't find everything I wanted in stranded, so I am using stranded for all my power and power drops (used OGR wire #14 & #16), but ended up using #18 solid thermostat wire for my switches and some accessories. Home Depot has it, it's readily available and you can get 2, 3, 5, 7, and I think 8 conductors. I used 2, 3 & 5.

As it turns out the solid wire worked out better for switches and items with screw terminals. Instead of using crimp forks or lugs, you can wrap the wire around the screws for good contact with no extra parts needed. A bit more difficult to pull through the holes in my bench work, but it worked out quite well for terminating and it wasn't really that bad to work with.

I used both.  14 stranded to wire the track and solid 18 - 22 for accessories.

All solid wire. 14 gauge is the largest, track power.

Thanks for your input guys.  I've also used both but didn't know if there was a rule as to which you should use for certain applications.

As a matter of fact I just bought a 50' spool of thermostat 18 gauge 5 conductor wire  at Home Depot yesterday for $18 and some change.

Rick

I am Wiring up my layout now. I searched the web and found these plus and minus comparisons for solid wire vrs. stranded wire:

Some advantages of solid core wire:

• Cheaper to produce
• More compact diameter for the same current carrying capability as stranded
• Less likely to fail due to corrosion

Disadvantages of solid core wire:

• Typically only available in small gauges
• Continuous flexing or vibration will cause the wire to fatigue and break

Some advantages of stranded wire:

• Very flexible and withstands a greater amount of flexing and vibration
• Easier to rout

Disadvantages of stranded wire:

• Diameter is larger for the same carrying capability as solid
• More costly to produce as the manufacturing process is more complex
• More likely to fail due to corrosion from capillary action & a high surface area

Hope this helps.

My LHS techie in whom I have much trust in these matters advised me to go with STRANDED period.

Each, Stranded v.s. Solid  has it's advantages as listed.  Most of the wiring in your home would be solid. Easiest, and most reliable termination.   Solid wire is available through size #2.  Sizes larger than #2 Solid would be hard to find.  IMO, size #8 is when flexibility becomes an issue. IMO.  Solid wire adds to neatness, and an orderly assembly, for the smaller size wires.

Edit/add (11/11/15): Note that equivalent stranded wire has a slightly larger diameter than the same size solid wire.  Stranded would also have more surface area.

Difficult to do this with Stranded wire.

This truck termination probably would not last long if it was solid wire.

If you use stranded wire consistently, it's best to invest in good termination tools and the correct forked spade, or I-let connectors. Solid easily wraps around a screw, (Clockwise, please), or inserts in a provided termination, Stranded, IMO, should not be wrapped around a screw terminal, the appropriate crimp on termination should be used.  

I use stranded #10 for the bus and stranded #18 for the feeders.  I picked stranded for the flexibility and also for the way I connect the feeders to the bus.  I bare about an inch or inch and a half of the bus, poke a hole through the strands, insert about 2 inches of the striped feeder and wrap it around the bus, squeeze tight and wrap with electrical tape.  No soldering under the RR.  Also, I buy my wire at one of the local electrical supply houses.  They tend to have better prices than the big box stores.

Ed

I used both solid and stranded wire for wiring the layout. For track leads(feeders) #18 solid to center hot rail and outside common rails,all leads 12 inches long, one of the common leads is soldered to the skinned segment of the other common lead, the end of this leads is butt spliced either to # 16 or #14 gauge stranded wire for soldering to the common buss wire. Solid wire is easier to offset set bend and clamp to the rail side for soldering. Currently I am considering buying #12 gauge solid bare electrical wire for the common buss, no skinning is required for soldering the common wires. Because I am using track blocks, I most likely will use either # 14 or #12 gauge stranded wire for soldering to toggle switches and to the barrier strips which are to be wired to the ac power connections on the transformers.

According to the Lionel Trains(TM) Official Blog:

       "Wire comes in many sizes in solid and stranded varieties. Stranded wire is really a bundle of smaller diameter wires wound together. Wire size is indicated by a number – the larger the number, the smaller the wire. Most house wiring in No. 12, solid wire. For your layout, we recommend a No. 16 stranded bus wire with No. 18 feeders. The feeders do not have to be as large because they are not as long and it is easier to attach the smaller wire to the tracks. Stranded wire offers better electrical flow (electricity flows around a wire, not through it) and it is easier to bend. We recommend adding feeders at least every 10 to 20 feet around the track.

For lights and other low amp accessories, even smaller wire can be used on the feeders. Lighted accessories should use No. 20 or 22 wire.Phonecable works very well for switch motors. It is color coded, easily available and cheap!"

I have actually never used stranded wire, but as I wire my new layout, it looks like I should seriously consider using stranded wire.  I have always avoided using stranded wire because of the apparent difficulty of attaching the wire to transformer binding posts, etc.

I use stranded for just about everything, in sizes from 12 gauge down to 18 gauge. The one thing I use solid for is Tortoise switch motors. For that level of voltage and current 22 - 24 gauge phone or cat 5 does the job.

The skin effect for 60hz is a non-issue for any wiring you'll do on your layout.  The depth would be about 8mm, far larger than anything you'll wire with.  If you have a wire that's over half an inch in diameter feeding your tracks, you aren't running O-gauge stuff, you're into the 1:1 scale!

I am afraid I am beating a dead horse here, but if you use THHN, you can use it for both your layout and your house. And then among solid or stranded, I prefer solid THHN if I need to wrap around a screw. An electrician showed me a trick for stranded, you leave the last bit of insulation at the end of the stripped wire to keep the bundle together when trying to wrap around a screw, but I still prefer solid.

If it has to flex, as others above have stated, you want stranded.

Stranded can have a cleaner appearance, if that is what you are after.

Both solid or stranded in the same size wire gauge can handle the same amount of current. The advantage of stranded is being flexible. 

It would be legal to use stranded in house wiring but it would cost more so solid wire is used.

Solid wire should not break if flexed unless it is a very small gauge wire or you bend over 50 times in the same area.

My personal preferance is to use 16 AWG or larger on my layout.

Lee Fritz

Dennis,

I hate to debate you on this but voltage flows through a wire not on the surface area as you are suggesting. Stranded wire only offers flexibility, no better flow of electrons with stranded. 

Lee Fritz

Lee, it depends on the frequency.  If you're conducting high frequencies, they do indeed travel on the surface of the wire.  Look up Litz wire, commonly used in RF applications for that reason.

When star wiring with home runs and no thought of attaching drops I prefer solid 10 or 12.  It is easier to pull long runs with twisted solid core wire.  Pulling twisted stranded wire tends to go "Slinky" on me.

However when doing buss wiring job I prefer stranded because it is more conducive to slitting and inserting each feeder.  I prefer to solder all connections.

quote:

The skin effect for 60hz is a non-issue for any wiring you'll do on your layout.  The depth would be about 8mm, far larger than anything you'll wire with

That is my understanding.

Do any of the command systems use frequencies that are high enough for the skin effect to be significant?

John, you are talking about cable TV and not electricity like in house wiring, and there you would be correct. Cable TV in your house is also low current capacity and will not burn you under normal conditions, it might shock you a little but that's it.

Also RF cable is used for cable TV mainly, and sometimes in 2 way radio antenna systems.

In regular electrical work the current flows through the conductor and not on the surface. If the current was on the surface of the wire in residential electric you would get zapped more often.

Lee Fritz

Here is an article on the Skin Effect.

Gentlemen,

    I am not sure of the engineering reason, however long ago when DCS 1st came out, I used solid wire until Barry advised me to use stranded, the stranded wire eliminated most all problems with my DCS, for some reason it does work a lot better with the DCS, not sure if Legacy is effected in the same manner or not.

PCRR/Dave

Dave,

That is interesteing to know. I have been using 12 AWG solid wire on my DCS unit between transformer and DCS and then to track is also 12 AWG. I have not had any problems in the past, but I am setting up a new layout and will see about using stranded wire.

Lee Fritz

It's my understanding, that in order for stranded wire to behave differently than solid wire when it comes to the "Skin Effect", the individual conductors have to be insulated from each other. There is special wire called "Litz Wire" for this.

Here is a link

I've always preferred stranded due to its ease of use.  If a certain connection (like a Lionel lockon or tinnerman clip) would be easier done with stiffer wire, I just tin the end with a bit of solder. 

Technically it is not the surface, but the electron flow migrate toward the outside of the conductor at much higher frequencies.  This effectively reduces the surface available for electron flow and resistance per distance goes up.

We can go on about this red herring for ever, but for a low voltage DC or 60 HZ AC source, the issue should be ignored.

Your better doing the trade off discussion about cost, flexibility and easy of effort.

Surprised we are not talking about how many strands!  It comes in many different configurations.   low and high count.  G

 I wired my bus wiring under the table with solid 14 gauge I think, maybe 16 who knows. 

I pulled it tight and tied it off at the ends of the layout.  So it stays in place and spaced fairly nicely.  I just tap into it with strand wire whenever I need it for track power, accessories, etc.

I space the taps apart so they can't touch each other.

For me not all stranded wire is the same.  I prefer the high strand count which makes the wire much more flexible.  Also the quality of the jacket or insulation is a factor to consider depending on your application. 

I never worried about the skin effect.  Kind of like using monster cable on your stereo speakers.  Once you've seen the size of the wire using in wire bonding the power transistors that are driving your speakers, the monster cable seems like a mute point.

Thanks, as always -- LOL re 1/1!  

Thanks Lee!  Totally out of my league, as the quote is from the Lionel Blog, and was not authored by me!  I do understand the "Right Hand Rule"  from Physics 101 at the University of Michigan though.....!

GCG,  I am interested in learning about strand counts if the number of strands makes a difference for a model train layout.  I would suspect they don't.

Thanks!

aussteve:  Looks great!  That is similar to the method that I used for the star wiring on the layout I just dismantled.  I used solid copper 14 aww wire.

BTW, our youngest son who installed high end home theaters while going through college would totally agree with your comment about monster cables.  He also said that cables had one of the highest "mark-ups", and that his very honest employer did not recommend them.

Yes, but they're not carrying any significant current, so the fact that they're not using all of the huge conductor still doesn't make any difference IMO.  As I said and CW expanded on, in order for stranded wire to make any difference, it has to have individually insulated strands.  Plain stranded wire looks pretty much like solid wire to RF energy for the most part.

The finer the wire and the more strands, equates to more flexibility to a point.  The concern with strand wire in my opinion is breaking strands while removing insulation and while crimping or using.  This effectively changes the gauge of the wire.  Most cases not a problem, but could be with low count strand operated near capacity.   G