Wire - Stranded vs. Non-

[John316]

I too read the subject line and said oh no. Might as well bring up the other dreaded topics.

LOL
John

John,

Want me to ask about next? What kind of coolant, or what kind of oil to use?

Just kidding...

God bless,

John

[JackConrad]

More important than what kind of wire you use is how well it is secured to prevent movement and/or vibration and how good the connections are at the terminations.  If it is a wire that has to flex evert time a door is opened, it should definitely be stranded.  Jack

[rampeyboy]

somewhere in a bus conversion tips type site, I read that someone recommended using heavy extension cords for the coach wiring. They based this on cost, but also I'm sure because it is heavy enough for a 120 VAC load, and flexible???

Boyce

edit: I also assume he meant to cut the ends off and hardwire the ends..

[rv_safetyman]

Wow, not only has this thread been civil, but it has had some great responses.

Gary, I don't recall seeing your page (at least the crimping part).  I recall seeing your test.  The crimping part of your page has some great tips.  Thanks for posting the link.

I hope most of you have an infrared temperature gun and use it on things like your tires and bearings.  It ****SHOULD**** also be used on your electrical connections periodically.  Any loose or bad connection will generate heat.  Many years ago, I used to borrow one from work (when they were over $200!!! ) and take it home.  Our house  had aluminum wiring through out (not just the main supply) and it was a terrible problem at the time.  The aluminum would "flow" and the terminations would loosen up.  Anyway, I would check our breaker box and outlets at least every six months.  Try to check the bus connections once a year.

Boyce, there have been "strong" discussions about extension cords.  The overwhelming consensus of the folks that I consider to be "practical experts" is that they should ****NOT**** be used for 120 volt application.  First, much of that type of wire is really cheap in terms of both wire and insulation.  Second the application is based on "open air" use.  That allows the wire to dissipate heat better.  If you bury it in a wall with no exposure to the open air, it can (possibly) heat up.  Not sure it would cause a problem, but why risk it.  Wire designed to be enclosed is pretty darn cheap.

Folks have advocated using extension cord for low current 12V/24V wiring.  Recall here that low voltage applications can have some pretty high amperage and that wire gauge sizing is quite important (i.e. you would not want to use extension cord for something like a headlight circuit.

Jim

[artvonne]

  Hobe is the guy who advocated using extension cords. As long as you use adequate guage wire for the load, which is easily found in wiring charts, there should not be any problem. Also, there is no law keeping you from using heavier gauge wire on any given circuit; 12g in place of 14g, 10g in place of 12g, etc...

  I remain impressed with the electrical systems in the old GMC Buses we scrapped, it was very comparable to aviation quality. Quality end connectors with nut and bolt connections, well routed and securely attached wire clusters and conduits, and heavy gauge well insulated wiring. The old 3751's and 4104's still plying the highways are a testament to the care and quality put into those systems.

  There is no reason the AC side of an RV couldnt be built as well, without it costing any more than a residential grade system. All AC outlets have screw connectors, no reason they cant be used with good end connectors on multistrand wire.

[47FLXclipper]

boogies "tutorial" on crimping and soldering is exactly right [and I think NASA would generally agree], it matches my experience over years in USAF aircraft electronics - any "hardening" by solder wicking back under the insulation indicates poor workmanship, and breakage at the termination indicates the same, from improper strain relief

Bill

[Hi yo silver]

I have to respectfully disagree with the use of extension cords for permanent installation.  The real concern here is the aging of the insulation, rather than adequate wire size.  If you refer to the appropriate section of NAPA 70, the National Electrical Code, you will find the details.  As an experienced fire investigator, I can tell you these standards were developed over many years, as a result of the investigation of fires that resulted in the loss of property and sometimes the loss of lives.  Now, I'm a laid back kind of guy, who believes that many rules can be bent, but this isn't an area to take shortcuts.  The insulation on extension cords will become brittle as it ages, and fall from the conductors leaving them bare.  I have personally seen the old cords, and even seen the results. 

On another note, the best set of battery jumper cables I have are made up of fine stranded welding cable.  When lesser jumper cables won't do the job, these cables will allow cranking like a new battery!  If you look at the cheapest cables you can buy, they are made up of a few relative large copper strands.  The best quality cables might be of equivalent size, but are made up of fine stranded cable.  The current travels along the outer surface of the wire.  The cable made of finer strands provides more surface for conducting the current.

My opinion.

Dennis   

[Hi yo silver]

Oh yeah, one more thing while I'm on my soapbox.  Throw away the RVIA book.  (Do I have those initials right?  Anyhow, the RV manufacturers group)  That's the standard that Fleetwood and other RV builders follow in slapping together those flimsy trailers like the new Fleetwood I use to have, that could have burned to the ground on two occasions, had it not been for Lady Luck.  Those are minimum standards, sometimes followed with the absolute cheapest components installed.  In my qualified opinion, Romex is not designed or intended for use in RVs or boats where terminals are subjected to constant vibration, whether "sufficiently anchored" or not.

Further evidence of the need for stranded wire is found on railroad diesel locomotives.  You won't find solid wire anywhere on one.  It's strictly stranded conductors. 

Great thread.  Be safe!

Dennis 

[Seayfam]

This has been some very good information... I was wondering why when I got my bus all the 110v wiring was stranded. Now I know and can sleep better at night.
Thanks to all your input

Gary

[rv_safetyman]

Gary, read through this thread again, and you will see that stranded wire has to be terminated properly.  Open up an outlet and make sure they used crimp-on fittings.  If not, I would put a load on every outlet and then take a look at the temperature in the box.

Jim

[artvonne]

I have to respectfully disagree with the use of extension cords for permanent installation. The real concern here is the aging of the insulation, rather than adequate wire size. The insulation on extension cords will become brittle as it ages, and fall from the conductors leaving them bare.  I have personally seen the old cords, and even seen the results. 

Dennis   

 I know what your saying about poor insulation that falls off the conductor, I have seen this myself. But I would argue it has nothing at all to do with extension cords, per se, as much as it has to do with general wire quality. The wire on the spools at the auto parts stores isnt always any better than the stuff inside the cheapo chinese extension cords sold at Home Depot. You need the stuff that stays flexible below zero.

[Seayfam]

Jim, thanks I'll look in the outlets tomorrow and make sure all is OK.

Gary

[crown]

 just my 2 cents. but hear in costa rica and i think all of centro america .
solid wire is not sold and cant be used all wire is stranded
most of europe also uses stranded wire also.the wire i used in my bus in from italy
a fine stranded 12 gauage rated for 120 v / 240 v. i used conectors on ends where neaded. john

[Barn Owl]

I am not going to take sides on this one because there is what I wish I had, and what I have. I'm not about to rewire my bus so I am using what the PO put in back in '79. Stranded for DC, Romex for AC. Thirty two years later and I haven't had an issue yet. I will post asap as soon as my bus burns to the ground, if I live to see it.     I don't have a lot of flexing in my bus, so I am fairly confident that the wiring will be fine for a long, long time. This is not a black and white, right or wrong thing for me. I look at wiring choices as Good, Better, Best. Good will work and is what I have, better is wonderful if you can, but there are many examples of Good doing just fine, and that doesn't necessarily make it bad, just not the best. Don't loose any sleep over this one guys.

[MikeH]

I appreciate all the input. I didn't realize when I started this thread that it was a hot button for many folks. I appreciate that the discussion has been cordial and polite.

One thing that seems to be a common in many answers is that we need to be careful of the quality of the wire. So the next question is how can you tell what is good quality wire and insulation? Before I started this thread, I most assuredly would have opted for solid wire, but now I think I would go with stranded. But if I walk into one of the big box stores and start looking at spools of wire, how can you tell whether it is quality or not? No sense opting for the "better" type of wire only to be foiled because the insulation peels off in a couple of years. That is clearly not "better".

Any clues on this? Do you look for a certain kind of manufacturing stamp, or do you ask the salesman what they use for coating?

Thanks. So far I am now slightly less clueless than before.

Mike