Solid versis stranded copper wire???????

[DrivingMissLazy]

The best wire to use, in my opinion is tinned, stranded copper, minimum 19 strands. It should meet UL1019 standards. It is not marine wire. The code for marine products is not NEC or UL. Larger boats do not have to comply with those standards. The marine standards that I had to meet manufacturing my ShorPower converters was LLoyds, ABYS and a couple of others I have forgotten.

When crimping lugs on wire, it is extremely important to use the proper crimping tool and a good quality lug. The crimping tool will cost $100 or more and once you start the crimp, you can not stop until the crimp is completed. The crimping action actually flows the copper of the wire and the lug so that it is impossible to obtain a poor crimp or a crimp that will corrode internally.

Richard

[kingfa39]

i used romex on mine because that was waht was in my travel trailer, that was 20 yrs ago and ive never ever had a problem with the wiring. standed wire is not recomended for ac voltage, however what ever you think. i just clamped everything as i went.
Frank Allen

[Sam 4106]

Frank Allen, Where do you get the idea that "stranded wire is not recomended for ac voltage"? That"s the first time I've heard that.
Thanks, Sam 4106

[DrivingMissLazy]

i used romex on mine because that was waht was in my travel trailer, that was 20 yrs ago and ive never ever had a problem with the wiring. stranded wire is not recommended for ac voltage, however what ever you think. i just clamped everything as i went.
Frank Allen

I seriously question the validity of that statement. I manufactured thousands and thousands of various AC power converters, all to UL standards, and all used stranded wire exclusively. I do not recall ever using solid conductors for anything.
Richard

[JackConrad]

My understanding is that stranded automotive wire meeting SAE spec J1128 does not meet AC wiring requirements, but Thhn stranded does meet code for AC wiring as long as it is inside approved conduit.  Jack

[bassfid]

AC current flow is subject to "skin effect"

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of a solid electrical conductor, such as metal wire. The effect becomes more and more apparent as the frequency increases.

Skin effect can be reduced by using stranded rather than solid wire. This increases the effective surface area of the wire for a given wire gauge.

Automotive applications  (DC) prefer stranded not for efficiency, but for ability to withstand vibration.

Fredm 4106

[DrivingMissLazy]

AC current flow is subject to "skin effect"

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of a solid electrical conductor, such as metal wire. The effect becomes more and more apparent as the frequency increases.

Skin effect can be reduced by using stranded rather than solid wire. This increases the effective surface area of the wire for a given wire gauge.

Automotive applications  (DC) prefer stranded not for efficiency, but for ability to withstand vibration.

Fredm 4106

Where I went to school (Air Force at Keesler) they taught about skin effect but it was only apparent when you got up to the higher frequencies. At 400 hertz it definitely had an effect. And we had to do things differently out in the field when working with 400 hertz.

At 60 hertz it had no apparent effect, as least so they said.

Richard

[bassfid]

"Although the skin effect is generally associated with RF and microwave circuitry, it often plays a significant role in switching power electronics, transformers, motors, and high power AC transmission lines. Whenever designing conductors for anything other than DC, it is advisable to be aware of the skin depth (a.k.a. depth of penetration)."

For full info & skin effect calculator:

http://circuitcalculator.com/wordpress/2007/06/18/skin-effect-calculator/

[boogiethecat]

It's interesting to me that on every forum dealing with busses, every time someone asks this question (solid vs stranded), it always gets out of hand as this thread has, and eventually arguements start, skin effect is mentioned, etc etc etc.  It's just silly.  Not that I need to chime in again, but skin effect is a real effect that has absolutely no meaning to bus wiring, as it only occurs with high voltages and frequencies that you'll NEVER see in a bus....unless you happen to launch yourself off the road and get tangled up hanging your bus on a 500kv power line or maybe a 100kw radio transmitting tower... at which point that's the least of your problems.

The bottom line in this whole conversation is, use what you want to use.  Stranded wire, Solid wire, boat wire, THHN, UL 1015, SAE blah blah, or whatever kind of wire you want to use may or may not be approved by the code writers for RV's, but then again they are not infallable gods either in their writings.  The code is simply a strong and reasonable suggestion for folks that don't want to or cannot do the research or think for themselves.

As long as the wire gauge you use is heavy enough to carry your proposed current without overheating, its insulation is adaquate to withstand the voltage you'll give it, its made of a material that won't degrade under the conditions you subject it to and the construction you use is robust enough to take whatever vibration and abuse your bus is going to give it and not cause shorts or breaks, just do it.  Stranded wire in an RV will always be a better bet than solid wire as long as the other requirements (voltage, current, insulation quality and mechanical) are met,  but as you can read here, just as many of us use solid housewire and get away with it just as well as do the nitpickers who adhere to the code like flies on sticky paper.  Personally, its 100% stranded UL 1015 wire in plastic conduit for my busses, or nothing, but that's just me.  Do as you will and do it well, and all you'll get is enjoyment....

CHeers

[DrivingMissLazy]

Thank you Boogie for a well thought out reply.

I think the only time an average person would run into skin effect would be if they were working on a larger aircraft that uses 400 hertz power.
Richard

[bassfid]

Skin effect can have an effect on efficiency (resistance) even at 60hz at high amp levels. My previous post also stated that stranded wire is not used for efficiency reasons, but for mechanical, ie:vibration etc.
This thread has certainly been beaten to death.   The consensus is stranded but busnuts are known to think/act outside the box.
Fred 4106

[Barn Owl]

PO used solid wire in '79 when the conversion on my bus was done. Didn't do the best job of keeping it supported and neat but it's still working after 28 years. I believe stranded is better, but for those with solid, don't loose any sleep over it, I'm not. Regardless of what type of wire you have be sure to check it on occasion. There is a converter in Florida (seems to be well respected among converters) that uses extension cords (with the ends cut off) for wiring. What do you all think of that?

Happy bussing,

Laryn

[Len Silva]

If you wired your coach in solid wire, it's all wrong - rip it out.  Same goes if you used stranded.

Len

[maria-n-skip]

So Len what do I use?

  I was considering fiber optics but I think the bends would be to sharp?


Skip

[niles500]

Try an enigma sheathed in a conundrum