romex in my bus?

[Jolly Roger bus 223]

i dont like the idea?
collins/ midbus body.
i need to get wire from one side to the other through the ceiling/roof.
wifes bus i am building and she wants to keep the ceiling as is.
i was trying to do 1/2" liquatite but the ceiling i have found out has 1"x1/2" cold roll in between the ribs and the 1/2" liquatite wont even fit.
i need something like romex but dont like that idea because it is solid wire and can work harden overtime and its near the roof so could get to hot while being used in the summertime?
would an SJ or S/O cord be better.
any ideas are appreciated.
would love to stay with stranded wire and wanted a raceway but i cant get it through there.
thoughts and ideas please.

[rossvtaylor]

So...having done some work on aircraft I've owned (under the supervision of an avionic tech or A&P)...I learned that only mil-spec or aircraft grade fine strand wire is suitable in an aircraft. Wait for it...there's a point here, really! I carried the same thought over to vehicles on the road, too.

But, the RVIA changed their guidelines to allow Romex-type wiring inside of motorhomes, trailers and RVs. My understanding is that, when properly supported, there isn't enough flex and vibration to cause that work hardening and breakage. Yes, I know the RVIA is an industry association and subject (I assume) to pressures from the manufacturers. But having seen lots of conversions and removed lots of old wiring during renovations, I've never seen any Romex-type wiring with any damage to the conductors. In fact, the MC-7 we live in was wired with Romex.

[rffffffff]

I can’t see any reason SJ or something like it wouldn’t work. I used romex in a lot of places and haven’t had any trouble but if you’re trying to snake a run through a tight place I think SJ is a bit more flexible and tolerant of pulling and snags or whatever you may run into. My 30a input wire runs under the bus on the outside for a while so it is 10awg SJ, or really SOOW I think.

[o1marc]

Vibration can cause the solid core to break. I understand stranded wire is better than soilid core on a conversion like ours. I use this:

https://www.westmarine.com/buy/ancor...QaAht0EALw_wcB

[Phatman]

Why do you have to run it in the ceiling? Most of mine is in conduit under the bus and then goes up in the wall.

[Jolly Roger bus 223]

Originally Posted by Phatman

Why do you have to run it in the ceiling? Most of mine is in conduit under the bus and then goes up in the wall.

would love to?
but this shorty with a collins/midbus body has a solid little i beam bus body frame that is u bolted to the chevy chassis rail so anything passing from side to side would have to be under the chassis frame and i dont want to cross under the driveline for anything.
have thought about cutting round holes in the bus body rail and still picture frame with angle but that is extra work that can be avoided if i could get through the overhead.
was thinking sj/so cord but not really keen on that because i have also read that since its already insulated then if you run it in insulation then it could get to hot.
plus through the roof of a bus?
i think i have figured out my solution by changing the outlet for laptop/phone charging to 12v and i run a different path to get 120 on that side.
knee wall at the stair well. was already trying to run 120 over there but that outlet needded to be above the windows and i am putting in a raceway for everything 120v because i know it can mess with the 12v signal if ran together..
my wife wanted a porch lite on the passenger side of the bus for when at campgrounds or plugged in to shore power.
to get her started the solar is basic and i will build for more to be added whether she likes it or not but she wont complain cause she knows i overbuild anything i do.
thanks everyone for your advice.
most 120 is done next is to figure out load center and although not a sparky by trade i do commercial/industrial HVAC and getting one of my service techs over for advice or to check things out is not a problem.
thanks

[Meathead]

Originally Posted by o1marc

Vibration can cause the solid core to break. I understand stranded wire is better than soilid core on a conversion like ours. I use this:

https://www.westmarine.com/buy/ancor...QaAht0EALw_wcB

Stranded wire is what all boat manufacturers use.

Ancor wire can be bought on amazon for less than West Highway Robbery Marine. I sure Marc knows that but someone reading this might not.

Peace y’all

[BlueDevil93]

Use multi-strand. No Romex. 30 years aircraft industry in Avionics. As well some marine experience.

[Danjo]

I found lots of Romex in an RVIA-badged Fleetwood. It wasn’t the cable, it was the connections. I wouldn’t use it. I’d go with stranded. After lots of deliberation I’ve decided that good quality extension cord is just fine as long as it’s protected from damage.

I e also decided to keep my factory headliner. It’s full of synthetic wool batting. I’ve found that it can be fished with a fish stick no problem.

EDIT: Another forum member pointed out that running an extension cord through walls and ceilings is not permitted per the NEC.

[Rwnielsen]

You can get stranded M/C cable in all the standard configurations. I use 12/2 and 12/3 stranded because it has less tendency to kink when fishing it and I'm generally by myself. I have a roll of 10/3 but it cost me $500 for 250'. 12/3 is perfect for my limited A/C plans. 1/2 & 3/4 flex with strategic junction boxes is my other option

[Rucker]

Originally Posted by Danjo

I found lots of Romex in an RVIA-badged Fleetwood. It wasn’t the cable, it was the connections. I wouldn’t use it. I’d go with stranded. After lots of deliberation I’ve decided that good quality extension cord is just fine as long as it’s protected from damage.

I e also decided to keep my factory headliner. It’s full of synthetic wool batting. I’ve found that it can be fished with a fish stick no problem.

EDIT: Another forum member pointed out that running an extension cord through walls and ceilings is not permitted per the NEC.

This is a good point Danjo. While reading the thread I was thinking a skoolie just isn't going to see the thousands of road miles a commercial freighter will do, so what risk is there really with some Romex. As long as you don't pull the wire through narrow places and leave some slack along the way...

HOWEVER, wire nuts have to be really really well applied. The risk is the connections.

[s2mikon]

Originally Posted by Rwnielsen

You can get stranded M/C cable in all the standard configurations. I use 12/2 and 12/3 stranded because it has less tendency to kink when fishing it and I'm generally by myself. I have a roll of 10/3 but it cost me $500 for 250'. 12/3 is perfect for my limited A/C plans. 1/2 & 3/4 flex with strategic junction boxes is my other option

Listen to the above. Anything else is a fools errand.

[Jbone32]

MC cable has a metal shielding. If concern is heat dissipation this would be counter productive..if money was not an issue i would use seal tight, it is air tight and water proof stranded wire would be the only option for me if i was pulling through any type of conduit not just for ease of work but the termination is cleaner IMO.

[BeNimble]

run the wire under the bus? it is the connections that are at risk for solid wire
how much do you really need?

[Rwnielsen]

Originally Posted by Jbone32

MC cable has a metal shielding. If concern is heat dissipation this would be counter productive..if money was not an issue i would use seal tight, it is air tight and water proof stranded wire would be the only option for me if i was pulling through any type of conduit not just for ease of work but the termination is cleaner IMO.

I'm not sure I'm following the "heat dissipation". If you stay within the standard ampacity and insulation tables there shouldn't be any excess heat. Poor connections and terminations cause heat.

[Jolly Roger bus 223]

i am past the romex thing?
figured out a different path and layout for liquatite.
but lets play the extension cord question game?
on hear years ago i was advised against using extension cord in insulated areas because it was already insulated and if in a conduit or insulation it would get to hot?
when i asked those questions for my big bus? i have two 100' extension cord hanging so i can get the generator away from it or plug into shore power.
my short bus is the one i am arguing with now?
would love to run extension cord or SO/SJ cord instead of liquatite but almost have all conduit ran.
what would be theside effects of an extension cord ran through non metallic liquatite?

[Jolly Roger bus 223]

also i would also pull only 10 or 12 awg to everything including 12v
anything i pull is going to have a spare.

[rffffffff]

I have soow in my bus in places and it’s fine. If you have a proper fuse or breaker on it you don’t have anything to worry about, but make sure the 12v stuff is over spec’d because voltage drop at 12v can be pretty nasty, or at least do the math before you run it. My diesel heater pulls a bit more that I thought on startup and it makes me want bigger wires than what’s already there.

If you’re worried about it at all re: heat on the 120v side, run 12awg on a 15a breaker and you’ll be extra double fine.

[Rwnielsen]

Keep your conduit straight and well supported, stay within the amperage rating of your SO cord and you will be fine. There's a separate table in the code book just for cords.

[DeMac]

Yes. NEC 400.7
However, the facts contained, therein, contradict the aformentioned instructions provided, by you.
Everyone knows that rubber (so insulation) has a short lifespan & does not dissipate heat well. Thats why SO must be run in free air. Exceptions include assemblies which have been UL listed. The facts are available, please look up the reference above. I don't make the rules, it's science, I do meet or exceed the code book, as it is the minimum standard. Please don't burry SO cable into a build. It will degrade.