RV Electrical Wiring Advice

[pneumatics]

So here is where it gets in the weeds.....
There is a subset of regulations for 120V Electrical Systems under (Art 551 RV, Art 552 PMRV) of the NEC 2017. I don't have a copy of the code but as is typical for these codes, industry that is affected is part of the writers of the code. In fact, most codes have entire sections written for RV's whether Park, Mobile or Transportable.
If somebody can cite this section of the code, give it a go.
But note that these codes are NOT intended for end users but rather to guidance and regulate manufacturers, installers, designers, etc. in common and acceptable practices.
Just me 2 cents.

[macdaddy1111]

[QUOTE=Judge;273308]Last summer I installed a Dirt Devil Central RV Vac. After thinking I was going to tap into an existing 15-A circuit I had another idea.

Heck Yeah Judge, Got a new project on the way now!

[The_Breeze]

Originally Posted by OldWEB

SJO is not robust. When the cable just lays around I think ozone or UV attacks the insulation to the point it just crumbles when it ages. But I do not make the rules, heck, it is hard enough to read the rules!
...cut...

I wanted you to know I sincerely do appreciate your taking the time to ferret that out. I will read until my head hurts too.

[The_Breeze]

Originally Posted by pneumatics

So here is where it gets in the weeds.....
There is a subset of regulations for 120V Electrical Systems under (Art 551 RV, Art 552 PMRV) of the NEC 2017. I don't have a copy of the code but as is typical for these codes, industry that is affected is part of the writers of the code. In fact, most codes have entire sections written for RV's whether Park, Mobile or Transportable.
If somebody can cite this section of the code, give it a go.
But note that these codes are NOT intended for end users but rather to guidance and regulate manufacturers, installers, designers, etc. in common and acceptable practices.
Just me 2 cents.

551 seems to address feeder systems (i.e. campground hookups). Still researching 552.

I actually thought that on the way up and back from picking up the fishing tape. You get a lot of thinking done in two hours.

I respect the opinions of those who've been around this block more than once, especially having done it for a living. I've run wiring too, in additions, home improvements, garages and had it checked by a friend. It always passed but it was always romex and I did it for no other reason other than that was the way it was always done and the only way I'd ever seen it done. No rationale beyond that.

My Father has some 12-2 romex laying around. The run along the bed support wall is short so I won't have expended a lot of time and energy to test romex against that angle. If it doesn't work, I'm pretty much left with two options: 1) use the SJO and keep the wiring inside or 2) drop romex through the floor, run conduit along the frame and pop back up under the bed. The SJO will never see the light of day so UV deterioration is unlikely or could take forever and a day?

I'm hell bent on not putting the inverter so far away from the batteries (other end of rig). They also cost me 4k so throwing my hands up is not an option at this point.

I have a test to run and some possible heavy thinking to do afterward. As for the termination points on SJO, I'm thinking there has to be a better way. Beau is a smart guy but even I balked at that one.

On a wing and a prayer. Wish me luck.

p.s. this article is from 208 and provides a little clarification. I learned a little something - where to start looking.

"NFPA 1192 Standard does not contain any electrical system standards.
It states Electrical Requirements by
referencing to NFPA70 Article 551 and ANSI RVIA/LV compliance."
https://diysolarforum.com/threads/nf...968/post-62351

[OldWEB]

I myself would not use "cab tyre" type extension cord, but in my past life I had installed miles of wire in control panels. I cannot remember the type of wire used (PVC?), but it was grey, single conductor (stranded). That wire I would not hesitate to use in this situation, it had a tough covering that I never saw deteriorate. It is available in #12 or #14 and all that is needed is you mark each end or ring them out after.

[The_Breeze]

Originally Posted by OldWEB

I myself would not use "cab tyre" type extension cord, but in my past life I had installed miles of wire in control panels. I cannot remember the type of wire used (PVC?), but it was grey, single conductor (stranded). That wire I would not hesitate to use in this situation, it had a tough covering that I never saw deteriorate. It is available in #12 or #14 and all that is needed is you mark each end or ring them out after.

The wire in question is 14-3 (14 gauge, 3 wire, single conductor). It's not gray but black SJOOW AC power cord (e.g. https://www.awcwire.com/productspec....wires%20inside).

It's oil resistant, not that it matters. A larger gauge is used in UPS systems for large datacenters (a past life). Not that it matters, the wiring will be tucked up against the outside wall, run under the counter top, under the shower, then under the bed so it will never see sunlight (UV degradation).

Take a peek and weigh in if you can.
https://www.lowes.com/pd/Southwire-S...-Foot/50148244

[cavie]

Originally Posted by The_Breeze

but you don't explain why?

to much code involved for this forum.

[The_Breeze]

Originally Posted by cavie

to much code involved for this forum.

Yes Sir but you can distill it for us, no?

Break it down into a paragraph, at most?

[OldWEB]

Originally Posted by The_Breeze

The wire in question is 14-3 (14 gauge, 3 wire, single conductor). It's not gray but black SJOOW AC power cord (e.g. https://www.awcwire.com/productspec....wires%20inside).

It's oil resistant, not that it matters. A larger gauge is used in UPS systems for large datacenters (a past life). Not that it matters, the wiring will be tucked up against the outside wall, run under the counter top, under the shower, then under the bed so it will never see sunlight (UV degradation).

Take a peek and weigh in if you can.
https://www.lowes.com/pd/Southwire-S...-Foot/50148244

That is what I refer to as "cab tyre" 3 conductor cable, not single. There are places where flexible cable is allowed and places it is not. What causes the insulation to break down is beyond ME, I just mention the two common ones, UV and ozone.

Running flexible cable in a data centre is most likely allowed, it is in a approved cable tray or raceway, only authorized peeps have access to it, etc.... I have run those wires too.

[OldWEB]

Romex has its rules too. Not to be run through floors or walls w/o protection, a maximum bend you can put on it (NOT 90 degrees), exposed runs to be protected.... and on. When I see pictures of some RV wiring (mine included), you wonder who does the inspecting at the manufacturer.

[16ACE27]

Here's two basic rules:

Use solid wire in installations where the wire won't move - this would apply to buildings and structures.

Use stranded wire in applications where the wire is expected to move - such as extension cords and vehicles.

Have you ever seen solid wire in a plane, train, automobile, submarine, ship?

The NEC has a section of code that applies specifically to RVs, which allows manufacturers to install solid wire like Romex in the house structure of the RV.

There should be absolutely no issue with using stranded (flexible) wire as the OP would like to do as long as it's rated for the volts/amps for his application.

[The_Breeze]

Originally Posted by 16ACE27

Here's two basic rules:

Use solid wire in installations where the wire won't move - this would apply to buildings and structures.

Use stranded wire in applications where the wire is expected to move - such as extension cords and vehicles.

Have you ever seen solid wire in a plane, train, automobile, submarine, ship?

The NEC has a section of code that applies specifically to RVs, which allows manufacturers to install solid wire like Romex in the house structure of the RV.

There should be absolutely no issue with using stranded (flexible) wire as the OP would like to do as long as it's rated for the volts/amps for his application.

Right. Makes sense. If it can't flex, it can break. Come to think of it, never saw a stiff piece of wiring in an A-10.

[Jahood]

Romex insulation is rated for 600 volts
Most extension chords are only rated for 300 volts

[Bill Johnson]

Originally Posted by The_Breeze

Right. Makes sense. If it can't flex, it can break. Come to think of it, never saw a stiff piece of wiring in an A-10.

What if you installed plastic flexible conduit and pulled stranded wire through the conduit. I would think that stranded wire would be much better in an rv, boat or auto. There are many wires going around the corner, why not disconnect one of them and hook a fish tape to it or string and pull it back and tie the new 3 wires to the original and pull all 4 back to the end around the corner

[JoeDS]

Originally Posted by pneumatics

Oh.. extensions cords are not the same as SJOOW. 14/3 SJOOW is rated 18 Amps, extension cords are rated as a stand alone device.

14 AWG 15Amp breaker


12 AWG 20 Amp breaker


10 AWG 30 Amp breaker


Its never wrong to oversize the cord, but it is bad practice to oversize the breaker.


The codes also assume you don't run a circuit for more than 80 % of rated capacity on a continuous basis.

[aaurbanelli@aol.com]

Originally Posted by cavie

this thread will give an electrician nightmares

I'm an engineer, not electrical or an electrician, but it scares me also. I've more experience with boats and there seems to be less electrical-do-it-yourself discussions - I guess electrics with water so close to hand gets more respect.

[cavie]

Originally Posted by The_Breeze

Thanks. That's at least a partial answer but what does the code attempt to prevent by requiring Romex over SJO? Is it the length of the run, heat, what?

I don't see myself making that bend with Romex and don't have the luxury of having everything out of the way like Thor did when they wired it.

Mostly heat degrading the rubber cord and the unsafe contion of the 120-volt cord when it does. Not a big safety issue when 12 volts is involved.

[cavie]

Originally Posted by OldWEB

Romex has its rules too. Not to be run through floors or walls w/o protection, a maximum bend you can put on it (NOT 90 degrees), exposed runs to be protected.... and on. When I see pictures of some RV wiring (mine included), you wonder who does the inspecting at the manufacturer.

Nobody. That is the problem.

[fastellman]

The diagram you posted looks very much like my ‘16 ACE 30.1. We removed the stove and replaced with an Induction stovetop. I was concerned about using the outlet under the sink. It had the outside tv on it. I ran romex from the circuit breaker box on the end of bed along the side of the bed and under the shower and refrigerator just like the existing romex for the outside outlet and the TV. There was an open slot in the breaker box where I added a breaker that I bought from Lowe’s/Home Depot. It was the same brand as the existing breakers. The whole install looks at least as good as originally built if not better as I cleaned up the mess a bit and vacuumed all the trash and sawdust. Have fun with your new install

[The_Breeze]

Originally Posted by JoeDS

14 AWG 15Amp breaker


12 AWG 20 Amp breaker


10 AWG 30 Amp breaker


Its never wrong to oversize the cord, but it is bad practice to oversize the breaker.


The codes also assume you don't run a circuit for more than 80 % of rated capacity on a continuous basis.

If this is true, why is my current 30A coach hardwired with 12-2 romex? 14-3 SJO has 300v and 30A capacity.