Teardrops n Tiny Travel Trailers

What is the consensus on running electrical wires in foam (XPS or EPS)? I've seen that people run it inside pvc pipes that are inlayed into the foam but it wasn't clear if they were using that for 120V AC, or 12V. I'd like to run some wire (insulated, 14-24 gauge depending on what I'm doing exactly) inlayed through the foam for 12V lights, fans, sound, etc. Obviously shorts can heat up wires, but practically, is there any reason I shouldn't do this?

Thanks for the help.

Running conduit will let you pull more or different wires though in the future. Embedding wire directly will work though I would fuse those wires before they go into the foam.

When doing this in a building you derate the wire capacity. Often by two sizes. So if your circuit needs a 16 gauge conductor, you end up using a 12 instead.

I ran a 1/2 poly water tube from where my tongue box will be to the cabinet in the cabin where all my wires run to, that is where the fuse panel is. It will be to run any forgotten wires after everything is closed up. Worked out well. I also ran a 18/6 cable and 2 16/4 cables (speaker wire) just so I have extra wires if needed at some point. Some will be for a thermostat if we add heat, and for a third break light on the hatch door. I ran some 12ga wire for 120v even though I don't plan to camp where there will be 120v. And now everything we need can be powered on 12v. The computer can charge while we drive, we have an AC plug in the TV.

I used this wire in 16ga for most all 12v, it is great stuff. https://www.amazon.com/Ancor-Marine-Grade-Duplex-Cables/dp/B000NUYC3S/ref=sr_1_2?ie=UTF8&qid=1523933650&sr=8-2&keywords=duplex%2Bwire&dpID=214cvzxTljL&preST=_SY300_QL70_&dpSrc=srch&th=1&psc=1

I didn't run any audio because we are going to use some bluetooth speakers we can move to where we need them, inside the cabin, out by the fire, back by the galley. That way we can have the music where we need it and not have to turn it up where other campsites might hear it.

I wouldn't use anything smaller than 18ga in an area that I wouldn't be able to get to in the future.

Sparksalot wrote:When doing this in a building you derate the wire capacity. Often by two sizes. So if your circuit needs a 16 gauge conductor, you end up using a 12 instead.

Good to know. Does the type of jacketing make a difference?

Sheddie had some thoughts on this based on legalities in NZ. Something about the wire insulation breaking down over time due to some chemical incompatibility. I wasn't too worried about it for 12v only.

About running conduit or other pull path liners, my advice is to not underestimate how big of a wire bundle you are going to end up with. Even with a "simple" system, lights and switches add up, features add up. Plan ahead.

Andrew Herrick wrote:
Good to know. Does the type of jacketing make a difference?

Not really, it needs to have a voltage rating consistent with what you're using.

Andrew Herrick wrote:

Sparksalot wrote:When doing this in a building you derate the wire capacity. Often by two sizes. So if your circuit needs a 16 gauge conductor, you end up using a 12 instead.

Good to know. Does the type of jacketing make a difference?

There are quite a few homes being built around here with ICFs. (Insulated Concrete Forms. Big hollow foam blocks that Lego together and are then filled with concrete.) They use a router or electric chainsaw to cut slots for the wiring. They use the same wire sizes for the circuit that they'd use in standard stud construction. I'm planning a new shop with ICFs.

I would think that if your wires are getting warm enough to melt foam, you've got the wrong gauge (and fuse) for the circuit. Foam or no foam. ???



Tony

All our wire is internal and exposed , no worries (EZ) … It’s a Camper , not House … JMHO