(Another) Rough electrical question

[Naio]

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 :B

I 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?

[time2roll]

Most RVs are wired with solid wire romex. Not many problems posted.

[Naio]

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]

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]

Thank you very much, ktmrfs and myredracer :).

[ktmrfs]

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]

Yes, it has a 20a plug.

[ktmrfs]

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]

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]

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]

Thanks, shastagary, and everyone:)

[Naio]

whoops, double post.

[shastagary]

if you want a long term use of extension cord as wiring between outlets i used a good quality rubber 14ga cord in my home built camper van i built in 1980. i have 4 outlets in it and used fiberglass boxes with punch outs for the wire inlets in them and have no problems with the wire pulling out and the insulation is still soft and has no cracking. it is not subject to uv rays from the sun or water that would deteriorate a normally used extension cord and is still in use today as i still have the van. not saying that any cord would last this long not the orange ones. i used a good black rubber extension cord.

[theoldwizard1]

vermilye wrote:
My only concern is with the quality of the outer jacket on extension cords. Some are fine, others are thin and easy to damage. If you use cords that are rated (S or SJ) and the various versions with additional specifications, you are good to go, although the insulation on the S or SO cable may be large enough to make it difficult to fit the holes in the boxes.

• The difference between "S" and "SJ" cordage is 600V rated insulation versus 300V insulation.
• The "O" means the insulation is oil resistant. "OO" means both the inner and outer insulation are oil resistant.
• The "W" means the outer insulation is water resistant.
• Stay away from any codage that has a "T" in its rating. This means thermoplastic insulation that is hard/brittle in cold, and soft when warm.

These ratings should be stamped in the outer insulation.

SJOOW would be good. If you want heavier insulation, get SOOW. Both are available from https://www.wireandcableyourway.com

[vermilye]

My only concern is with the quality of the outer jacket on extension cords. Some are fine, others are thin and easy to damage. If you use cords that are rated (S or SJ) and the various versions with additional specifications, you are good to go, although the insulation on the S or SO cable may be large enough to make it difficult to fit the holes in the boxes.

Another solution it to look to the boating industry. GenuinedealZ sells a flat stranded 600V cable that works well with standard electrical fittings. Expensive, but probably the best solution. Again, because it is stranded cable, you won't be able to use stab type receptacles. There are back wired receptacles that use the side screws to clamp the wire that work well with stranded wire. The Leviton 5252 is an example.

On Edit - Just saw the GenuinedealZ post made while I was typing...