Running wires: under or over?

[m00py]

So I'm in the process of ripping the aluminum sheet metal that lines the inside walls of my bus and underneath it all is spray foam that Champion had applied during manufacture. There's spray foam in the walls, in the ceiling and even underneath the bus. I haven't drafted a floor plan yet but since insulation is the first step I figure I'll need to figure out how I'm going to wire things first. So here's the question: Do I scrape off the spray foam and run them through/behind the fresh insulation or do I put the insulation down first then run them on top? I've seen people lay down insulation, then wire, then spray foam before. I'd like not to mess this up so tell me what you did with your wiring, what kind of insulation you put in and why you did it that way. I'll be at that step in this process in no time.

 

[bansil]

So many variables,

I used conduit as a wire chase and left a pull wire in it, this has helped during the couple wire add on's and modifications over the years

I have seen spray foamed over wiring, spray foam channels cut out and wire run and the foamed over

not much help, just some more ideas to ponder, worst part is you could never pull more wire etc, due to foam encapsulation

look at pdbreskes build for one way

 

[nat_ster]

Run 2x4 strapping horizontal on the entire inside of the bus.

This gives you a proper thermal break, a place to screw everything on the inside to, and a nice clear path front to rear for all wires and pipes.

Without strapping, every fastener you use from the inside into the metal will condense, form water, and cause rust / mold.

No interior fastener should ever go from the inside into the bus metal. That would make it a thermal bridge.

Nat

 

[m00py]

I'm sorry I'm having trouble picturing all of this. Do y'all have any pictures as an example?

 

[bansil]

I'm sorry I'm having trouble picturing all of this. Do y'all have any pictures as an example?

the-camel-conversion-project-

it 50 pages, not sure where wiring is though look at page 21 for an example and then you will have to cruise 10-30 maybe

 

[Albatross]

Personally, I would do wiring by running a conduit, and leaving a pull-wire. You can enclose it in the walls/ceiling/flooring that way, and as long as you're not doing MAJOR renovations, you can always replace, adjust, or make small additions/modifications that way.

As a techie, I know that what I think is the coolest, most epic thing to build in today will be outdated in 6-12 months, old-skool at 2 years, and what-in-the-****-was-i-thinking by 5; and I know that as a human, I am going to screw something up, so I should leave room for the ability to fix it easily, or change it out completely if that's what is needed.

 

[roach711]

I ran my 12v DC wiring along with the original interior bus wiring without any special protection. My 120v AC wiring is in flexible metallic conduit separated from the 12v wires so there's no problem with induced voltage in the DC wires.

Here's some of the original 12V DC wiring which is mostly run inside black plastic wiring conduit. I ran my wiring in or around those conduits.

 

[nat_ster]

I'm sorry I'm having trouble picturing all of this. Do y'all have any pictures as an example?

Jatzy used strapping.

http://www.skoolie.net/forums/f27/armageddon-the-smell-of-airborne-rust-8870.html

I used strapping.

http://www.skoolie.net/forums/f11/the-four-season-prime-10138.html

And there are others.

Nat

 

[m00py]

Jatzy used strapping.

http://www.skoolie.net/forums/f27/armageddon-the-smell-of-airborne-rust-8870.html

I used strapping.

http://www.skoolie.net/forums/f11/the-four-season-prime-10138.html

And there are others.

Nat

Nat what do you do? I'm only on page 8 and I am blown away by the level of skill and knowledge you have about this stuff.

 

[nat_ster]

Nat what do you do? I'm only on page 8 and I am blown away by the level of skill and knowledge you have about this stuff.

I'm a farm raised country boy / small contractor that does everything from metal fab to residential construction.

Today I'm working on hooking up a half million BTU coal fired hot water boiler for the 12 bay bus shop.

I started a thread last year called $hit I do for money. I have a pile of pics to upload when it starts getting dark to early to work out side.

This year I did some landscaping, roofing, auto / heavy equipment repair, this boiler removal / install, demolition, and a pile more.

Just before my divorce I realized the 80 / 20 rule. 80% of the work on most job sites gets done by 20% of the man power. 80% of the money gets made by the boss.
I was one of the 20% working my a$$ off, getting no where in life, and making pricks rich. So I cut out the middle man, and became my own boss. Now I do most the work myself, and only hire a man or two sometimes when I just can't do the work alone.

The best part is now I have time for my loved ones. Unlike when I punched a time clock, I have the freedom to take the time to look after my wife and kids. Now they come first unlike before when work came first.

I love the diversity of doing alot of different things. I have a hunger to learn new things. I don't smoke or drink, I just read and tinker on my many projects.

I spend many hours on this site trying to help people that don't have as much experience yet as I do. Many have helped me, I try to pass the favor onto others.

Nat

 

[veglorde]

I, reading this so many years later wondering how the **** I’ll be wiring an AC outlet on one side of my bus when the inverter is on the other (through the ceiling, of course, but it scares the crap out of me to plug in a Vitamix that’ll be powered from so very far away) (hence why I’m here), thank you, Nat.

 

[Rwnielsen]

Voltage drop

I, reading this so many years later wondering how the **** I’ll be wiring an AC outlet on one side of my bus when the inverter is on the other (through the ceiling, of course, but it scares the crap out of me to plug in a Vitamix that’ll be powered from so very far away) (hence why I’m here), thank you, Nat.

Run #12 wire to all your outlets it's good for 20a (16 continuous) and voltage drop over the length of a bus will be insignificant. Use good outlets. I only use 20a outlets at work. Voltage drop is a complex equation involving length, guage, voltage, load an ambient temperature. There are tables and apps but I wouldn't be too concerned in a bus.

 

[ol trunt]

I'd be more concerned with the size battery bank it will take to run that AC than anything else.
Jack

 

[DeMac]

Lots of rvs use romex, cheap wood, also leak, burn, etc. (Minimum Standard). For your safety, its worth a couple extra bucks for the mc 12/2 Roach mentioned and a maybe little bit of conduit (Albatros). You can feel safe running it exposed high across the interior of lower cabinets, closets. Plus thin walls require more physical protection.

 

[bus-bro]

The space between the floor and seat rail worked well for me as a place to run wire out of the way. Used regular water proof NM cable.

 

[Phatman]

Just be careful with MC cable (we used to call it BX). I’ve seen that stuff get kinked, cut the insulation on the wire, and then after it’s all covered up it shorts out and then you have to trace it out to correct it. If you do use it, make sure you the little red anti-short bushings that come with it.