How difficult is it to run wiring in foam walls in trailer?

[profdant139]

My small inverter is starved for juice -- I am pretty sure it is because we have it running off the thin 12v wire that feeds the cigarette lighter socket. I want to run heavier wire from the converter to the inverter.

My question is pretty simple -- how to fish the wire? The wall panels are a sandwich of paneling and styrofoam. It is not like fishing wire at home, where there are voids between the studs. Will ordinary "fish tape" penetrate the dense foam?

Thanks in advance for your advice. Obviously, I am not yet an expert at electrical repairs.

[profdant139]

Thanks, Matt! I am seeing a consensus here -- this is a doable deal.

[Matt_Colie]

Watch for notes in-line and at the end.

profdant139 wrote:
It never occurred to me to mount the inverter near the battery, but I think I could do that.
=> Yes, you should.

Please forgive the simplistic questions, but does that mean that I could attach leads to the battery and then come right through the front wall of the trailer to the inverter? I would seal the holes in the trailer -- the batteries are on the tongue, inside plastic battery boxes.
=> Yes, it does. Just be sure to put a down loop in the cable so that they don't conduct water into the wall laminate.

I would then mount the inverter on the inside of the front wall and run a 120v cord from that point, using surface wire mold.
=> That is the plan.

This solution, if it works, avoids the issue of hooking the inverter to my converter.
=> And lots of others as well.

This sounds too easy -- I think I am missing something.

=> No, you are not missing anything important.
=> Yes, it is this easy. You can make it a lot more difficult if you chose to, but this method is clean simple and straight forward. Put the inverter some place that it has air too cool it and you can see the indicators (it probably will have).

** I did forget to mention a fuse or breaker that should always be included where you come off primary power.

** If you are going to run a laptop and a printer (I do), for the cost, you can try a cheapo modified square (I refuse to call it sine) wave inverter. If it does alright, you just saved a bunch. If something complains about the poor AC, you can probably sell off the MSW inverter for a good portion of the original price.

Matt

[westend]

Connect your 800 W inverter directly to a circuit breaker/fuse and then to the batteries. Use 8ga or larger wire. The circuit breaker/fuse can be attached directly onto the battery terminal. Size the breaker/fuse to the size of the wire used.


Look at how I fused the battery lead (red) in this image:

[SoundGuy]

profdant139 wrote:
... and put together a simple "how to" for other non-experts who need occasional 120v power while dry camping.

Exactly what I did. We normally camp on electric sites but because a few times each season we lose campsite power for any one of a number of reasons I installed a 1000 watt PSW inverter in the trailer's front pass through cargo compartment and wired the outputs to dedicated receptacles - 3 inside the trailer and 1 outside. If we lose shore power we carry on as usual, making coffee or toast, running fans, even my wife's hair dryer set on low. :B

[profdant139]

Niner, unfortunately the laptop is the real issue -- it is a big MacBook Air, and I need it for work. (I work even while we are boondocking -- I write a column on current developments in financial law -- the most boring topic imaginable.) I then upload the columns to the publisher every weekend, when we go to town for groceries.

So even the 400 watt inverter was not doing the job, probably in part because of the inadequate wiring and partly because of the "high wattage brick." That's why I think a bigger inverter makes sense -- an extra cushion of capacity.

I am getting more and more comfortable with the idea of coming right from the battery on the tongue and up through the floor (not the fiberglass). There is a junction box right near the battery, out on the tongue. I will open it up and look inside to see if I can tap into those connections for my power source.

I will probably not be able to get to this project for a couple of weeks (due to actual work), but my hope is to take photos and put together a simple "how to" for other non-experts who need occasional 120v power while dry camping.

[NinerBikes]

Get a 150 or 175w inverter to replace the one that died. Problem solved, still plug it in the lighter socket. Or get a laptop that is more energy efficient and uses less wattage in the brick.

Many ways to solve your problem, but a bigger more powerful inverter isn't one of them.

[SoundGuy]

MrWizard wrote:
yes..mount inside up front, and go thru the wall to the batteries

No way I'd go through the wall when the trailer floor is right there and is the better option because you're not cutting through exterior fiberglass or aluminum siding.

[SoundGuy]

profdant139 wrote:
SoundGuy, that is very helpful -- thanks! Did I see fuses on the lines running to the battery?

Mine is a 1000 watt PSW inverter and because I typically don't pull any more than ~ 60 amps or so when powering a 750 watt toaster I used an 80 amp fuse in the positive cable where it connects to the trailer battery's positive terminal. My run is ~ 6' from the inverter to the battery so for this application I used 4 gauge cable ... other cable gauges can easily be determined using this Blue Sea DC Wire Gauge Chart.

[MrWizard]

very few people connect an inverter to the converter battery charge line, because it is usually 'Under Sized' for large inverters, and a long run from the batteries

yes..mount inside up front, and go thru the wall to the batteries

the alternate is mount near the batteries in an outside compartment, and use a 15 to 30RV pigtail and plug the shore cord into the inverter, this powers all the TT 110v outlets, no special inside dedicated wire run needed

finally as noted, mount inverter near the converter, attach inverter wires to converter battery wires, route inverter 120v power to outlets using a transfer switch, break out the outlet feed from the CB, and run thru the transfer switch

i think either method one or method two, are your best choices

method three offers the chance to mis-wire something at the TS

[profdant139]

SoundGuy, that is very helpful -- thanks! Did I see fuses on the lines running to the battery?

[SoundGuy]

profdant139 wrote:
Please forgive the simplistic questions, but does that mean that I could attach leads to the battery and then come right through the front wall of the trailer to the inverter? I would seal the holes in the trailer -- the batteries are on the tongue, inside plastic battery boxes.

I would then mount the inverter on the inside of the front wall and run a 120v cord from that point, using surface wire mold.

Mount the inverter in your trailer's front pass through storage compartment, run the cables to the battery location down through the floor and to the batteries, and wire the outputs from the inverter to a couple of duplex receptacles mounted inside the trailer. Pics of my own installation start here. It is too easy. 🙂

[time2roll]

profdant139 wrote:
time2roll, you are right that extension cords running around the interior are not pretty. But these would be for occasional use -- not permanently installed. When not in use, the cord is rolled up and stowed neatly.

I understand. I got bored with the entanglements long ago as the devices etc. seemed to multiply. We do better with all outlets powered by a 300w inverter so we can all charge, play, watch, surf as we like without the central or multiple cord issues.

Wiring is not that much. Now just push a button and all outlets are powered up.

[2oldman]

Naio wrote:
2oldman, I don't see the inverter in that.

Part two talks about inverters.

[2oldman]

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