My from-scratch van build is progressing slowly, as I get an afternoon here and there. Right now I am doing house wiring, and something is worrying me. So I thought I'd ask you all :BI went to an s&b electrical supply shop (a pro shop, not a home depot), told them I was cutting up 14ga extension cords for the wiring, because I thought it would handle movement better than romex, and asked what they recommended for boxes.They suggested I use the kind where you push the wire through one-way slots that grip the wire. I am screwing the plastic boxes to the steel wall of the van (with insulation behind) and ziptying the wire runs in the walls, with protection between zipties and wire housing.I have installed the boxes, run the wire, and started putting in outlets. But now I am second guessing. The plastic that grips the wire where it enters each box... isn't the movement of the van going to mean that eventually it damages the wires and starts a fire?What do you guys think? Should I replace these boxes? It was really hard to get the extension cord, with its thick housing, through the slots -- I think there is no way I could add a protective layer.I have had so many one step forward, one back things on this van. I don't want another, but I don't want a fire, either. Advice? Opinions?

The extension cord may not be ideal when burying it in the build. Depending on the box style you may be able to use romex clamps.In a house the romex is also stapled to a wall stud within X inches of the box by code. In a mobile application you could fasten with this.As you install the wire leave enough extra at each box so that if you need to work on it later you have some slack.

I would never have used an ext cord because the insulation will dry out and crack eventually.Best to do it right or not at all.

ScottG wrote:I would never have used an ext cord because the insulation will dry out and crack eventually.Best to do it right or not at all.120V wiring in RV slides is with stranded wire. Can't say it is the same as insulated 3 conductor rubber jacketed wire sold by wiring supply houses.I wouldn't use "extension cord" but look for the 12ga and 14ga jacketed stranded wire sold on spools by the foot.On my trailer it goes to metal boxes using the push through plastic "clamp" then wired to the outlet or spliced in a box to romex.However, using 14ga solid wire in something that slides in and out is NOT a good solution.

It is your van and you can use common sense, as you have, without worrying about stick- house codes, etc.Agree totally with above advice about leaving lots of slack. It is a nightmare trying to change an outlet later if need be, and there is not enough wire in the box- especially if the wire is poked in a hole in the back of the receptacle and breaks off so now it is too short, instead of using the side-screws. You need enough slack wire to cut off some more insulation and have enough left over to grab onto to get it on the outlet. Also make sure all three wires have lots of slack. One too-short one and you are doomed.I had a GFCI problem in the 5er it took a big effort to find, where the Romex white wire insulation had a small cut just where it went in the metal box which was grounded. After finding that (took a while!), of course there was no slack to pull out and fix that. The wires in the wall had no slack at all going into the box, and whoever did the job at the factory must have cut that insulation somehow. Then they put the wall on afterwards I suppose, so no hope of getting anything fixed later. I had to break into the wall and afterwards fake up a patch that didn't look too awful. Huge PITA.IMO stick with your plan and just leave yourself lots of wire in the box so you can change outlets later if need be.

buy the screw terminal outlets, don't use push in outlets with stranded wireeven with romex solid gauge wire, the push in type come loose in an RVi assume you mean 3-wire, outdoor type extension cord, NOT 2-wire zip cord, that some people might be thinking aboutgood outdoor cord is very rugged and NOT going to dry out and crackjust anchor/clamp it good, and should not have any problemsput a rubber grommet/bushing where it passes thru metal surfaces

(Another) Rough electrical question | Good Sam Community

time2roll
Nomad
Nov 19, 2017
Most RVs are wired with solid wire romex. Not many problems posted.
Naio
Explorer II
Nov 19, 2017
That's good to know, Mex!

I just used old construction cords that I had a lot of. You know, the ones with the messed up plugs and stuff. Color coded for ac, dc, and inverter runs.

But I do have a lot of romex, too (unused, leftover from construction jobs). I just worried that when the van moved, stiffer wire would put too much stress on the connections -- they would be the fulcrum points.

Anyway, I can use some 10 or 12 ga for that 20a outlet.

I tend to lie awake at night and think about potential problems and their solutions. Sometimes this is very useful and sometimes it is not. The wire flexing at connections was one of those. Perhaps it is overkill, but it is done now -- I am not gonna rerun all that wire :)
MEXICOWANDERER
Explorer
Nov 18, 2017
Is it not NEC code that a receptacle cannot represent a connection that has insufficient amperage to power it?

I used 20-amp Bryant nylon nickel plated marine receptacles and Deka 10 AWG tinned marine individual wires throughout my bus.

Naio, if you are near a city of 500,000 or more, many scrap metal yards will sell wire by the pound. It does take some telephone research to find a ripe prospect.

When buying used wire bend it double with your fingers. The slightest trace of surface cracking or crazing at the bend eliminates it as a contender.
Naio
Explorer II
Nov 18, 2017
Thank you very much, ktmrfs and myredracer :).
ktmrfs
Explorer II
Nov 18, 2017
Naio wrote:
Yes, it has a 20a plug.

then it requires a 20A circuit with #12 wire by NEC code. see my updates in my post
Naio
Explorer II
Nov 18, 2017
Yes, it has a 20a plug.
ktmrfs
Explorer II
Nov 18, 2017
Naio wrote:
Another question: I put in a 20amp outlet, on its own circuit, for my PD9280. Like a doof, I wired it with the same 14ga. It's about 4 feet to the electrical inlet, and the PD92980 says it is 1300watts. That can be continuous for many hours, though, IIUC.

Do I need to rewire this? 10 or 12ga romex? I have some of each.

I believe you really should have it connected to a 20A circuit with #12. IIRC NEC derating for dedicated appliance is 80% so a 15A ciruit can't be used for a dedicated appliance that draws more than 12A continous. Now the PD9280 may only draw 1300W, but the PF is not good and it probably will draw more than 12A. My PD9260 draws more than 1400VA, the 9280 will be even higher under max load.

One clue, the website says it requires a 20A outlet. and a 20A outlet can't be used with a 15A circuit. the other way around is ok, but not a 20A outlet on a 15A circuit. and a 20A circuit requires #12.

doesn't make any difference how short the run is, by NEC it requires a 20A breaker, #12 wire.
myredracer
Explorer II
Nov 18, 2017
Naio wrote:
Another question: I put in a 20amp outlet, on its own circuit, for my PD9280. Like a doof, I wired it with the same 14ga. It's about 4 feet to the electrical inlet, and the PD92980 says it is 1300watts. That can be continuous for many hours, though, IIUC.

Do I need to rewire this? 10 or 12ga romex? I have some of each.

You need to take into account the power factor of the converter. There is an older RV.net thread here that discussed the PD9280 and requirements on the 120 VAC side (warning, very technical) - looks like you need #12 wire, but #14 *might* be okay depending on how high the DC charging current will get. If not too difficult at this point to replace the #14, I would go with #12 and never have to worry/wonder if it's enough.
Naio
Explorer II
Nov 18, 2017
Another question: I put in a 20amp outlet, on its own circuit, for my PD9280. Like a doof, I wired it with the same 14ga. It's about 4 feet to the electrical inlet, and the PD92980 says it is 1300watts. That can be continuous for many hours, though, IIUC.

Do I need to rewire this? 10 or 12ga romex? I have some of each.
Naio
Explorer II
Nov 18, 2017
Thanks, shastagary, and everyone:)

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