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I hear you Harry, but I don't buy it.

I've had 4 RVs all wired with Romex and never had a solid wire failure -- a couple of them had quite high mileage with lots of rough roads.

Many (most?) commercial RVs are wired with Romex -- I just don't see them taking the legal risk of doing this if there was any real problem.

The low freq vibrations you get driving an RV over roads just don't seem to me to be the kind of vibration environment that would cause wire failure.

I spent some time searching for actual reported instances where people reported real failures of solid wired in RVs -- I could not find any.

I could be wrong, but just don't see it as a real issue. I'd like to see some hard evidence.

Gary
Hi Gary. I made a decision for my own work to rely on:
  • Data sheets
  • Known good practice
  • Electrical code (as much as possible)
  • Asking experts
Some, but not complete component testing, because I don't have the capabilities to test everything,

If I spent a little too much on components and ended up with very low failure rates, I am happy with that.

For the short wire lengths in a van, it isn't worth while for me to consider that I might be smarter than ABYC guidelines and the wire data sheets and shave off a few bucks in wiring.

The wire that I suggested is relatively inexpensive and widely available. I wouldn't wire a house with it, but a van - sure.

I know that you are looking for hard data and I am not in a position to supply it. I actually enjoy pushing on what can be done in a van electrical system but I have just chosen to be conservative about wire application guidelines.
 

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Hi,
The wire current ratings depend on the application. For home wiring, the 15 amps for #14 is used, and is conservative -- probably because home wiring often goes through insulation.

I think that the ratings that the American Boating and Yachting Council (ABYC) provides for marine applications are closer to RV applications than home wiring standards.
The ABYC ratings for #14 go from 15 amps up to 35 amps depending on the temperature rating of the wire insulation, but for wire with insulation rated at 90C (which is quite common), its 30 amps except in engine rooms, where its 25 amps.

Here is the table: http://assets.bluesea.com/files/resources/reference/21731.pdf

The BlueSea Circuit wizard uses the ABYC ratings and also takes into account voltage drop -- so, it seems like a good way to go. The ABYC ratings are for AC or DC.

Gary
Hi Gary,

I agree with you and think that following ABYC guidelines is a much closer model for a van electrical system than a home.

ABYC guidelines include using stranded wire and crimped connections, so that is what I do.

The one short fall of ABYC is that since it is designed around boat use, the assumption is that the wire insulation doesn't have to be tolerant of flexing when it is cold outside and not crack, so I go the extra mile to buy wire that also deals with that aspect.
 

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LOL, I used bell wire, phone wire, Goodwill lamp cords, ReStore extension cords and scrap solid wire. I did use proper stranded 00 wire for the battery to inverter connection.
 

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I bought a Renogy 2000w inverter with a hardwire connection and remote on/off switch.
I'm going to hardwire a single 12/2 piece of Romex (solid), because I have some, from the inverter to a single receptacle above a countertop.
The inverter will be fastened to the inside of a (ventilated) cabinet, the 12/2 will be fastened.
I'm going to guess that a possible temp range for the interior of the van will be 0-120F (sitting parked for extended periods in either heat or cold).
I'm not concerned with vibration and I'm not concerned with the wire's insulation failing from temp.
There is absolutely no point or advantage to going out and buying 12 ga stranded wire to run 115v AC, 4' from the inverter to a receptacle.
And I don't see any reason why the OP should use stranded in his application either, unless he needs to pull it through conduit and some tricky bends.
The only thing I would recommend is bumping up to 12 ga.
 

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I don't see 14 gauge as "minimal" for the AC side. As long as it's fused at 15A max, that's what's used in every house in the country (hopefully). The runs in a van aren't anywhere long as some of the runs from one end of a house to the other, and the AC voltage drop at 120V is minimal... not enough to make a difference.

I don't think that the OP has to feel like he's "just squeaking by" with 14AWG.

I prefer stranded wire in my van, but I've seen lots of commercial RVIA-approved RV's wired with Romex.
I said it is ok. 14 is the minimum for a 15 amp circuit unless you can ensure the temperature stays low enough then 16 is actually the minimum. I have no problem with 14 gauge solid wire for the AC side and I said so. But I will say it is the minimum, not just squeaking by, the standards allow plenty of overhead for safety. If you adhere the electrical standards, either code, rvia, or as I prefer AYBC (American Boat and Yacht Council) you will be fine.

You can squeak by with 16 gauge in a temperature controlled environment on short runs. Adhering to the minimum standards is ok, I said so, and I didn't mean to imply anything negative. My design philosophy is just different. I deal with the hassle of stranded wire even though I hate it for the extra margin of safety in my environment. I run heavier wire to have less losses because my power might be limited. Nothing unsafe about 14 guage AC wiring for 15 amp circuits, I never said there was. But I would say I view it as the minimum. I would never recommend 16 gauge, so I view 14 as the minimum.
 

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So I'm going to have a 15amp shore power connection , a 1000w renogy inverter/charger , and probably 3 outlets in the van . Would I be ok to use 14awg Romex wire throughout my install as I will not be running anything high power.....just laptop charging and that sort of thing .

So 15amp shore power going to main breaker 15amp , then onto inverter input , out of inverter to another 15amp breaker, then out from breaker to my 3 outlets . All using 14awg wire, does that sound correct
One thing might be an issue... if you plug your shore power extension cord into a 20 amp receptacle (the plug is similar and interchangeable), you wiring is protected to 20 amps from the load center breaker, but the 14AWG Romex in your install is rated for only 15 amps. 20 amp service uses 12AWG. Typically it is okay to plug multiple 15 amp devices (tools, etc) into 20 amp circuits, but they individually draw only 15 amps in their respective cable, and the cable leading up to the outlet from the load center is rated for and protected at 20 amps. In a worst case scenario, you could have several items drawing 15 amps in their respective cables, but the wiring (internal to your build) from their respective receptacles in your build to the outlet in your garage is rated for only 15 amps and protected at 20 amps. This could cause a fire. To play it safe, you might consider using 12AWG. Especially if you would ever sell your van to a third party who may not follow your rules.

(The ground can be top or bottom, I just oriented the pictures so the 15A and 20A markings would be right side up. Of course, that would be under the cover plate anyway, the obvious difference is the horizontal slot on the common wire.)

white-leviton-electrical-outlets-receptacles-r62-cbr15-00w-64_1000.jpg white-leviton-electrical-outlets-receptacles-r62-cbr20-00w-64_1000.jpg
 

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I doubt there will be any 15 amp devices plugged in, let alone multiple 15 amp devices.
Anything trying to draw more than 15 amps from the circuit will trip the 15 amp breaker.
So, no fires.
 
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