Fishing Electrical Wire in a Finished Bus

[indurain]

Hello all - I’m looking to add a second solar wire/circuit line to my rig to tie in 2 new solar panels to a dedicated solar charge controller. The unfortunate part is that my rig is mostly completed - inside and outside. There’s spray foam in between the exterior sheet metal and the interior wood panel walls. Wondering if anyone has experience fishing 10 AWG or 8 AWG wire from the roof down to a skoolie belly box (~15-20 feet mostly vertical but some horizontal length) so the wires aren’t exposed on the outside of the rig? If so, any best practices?

Perhaps fishing wire under this situation is not the best use of time. One other alternative is to attach some TECK90 10 or 8 AWG wire along the outside of the bus skin and secure it down real tight with some self tapping screws/VHB tape and conduit clamps.

Anyone got any advice on one of these methods or a completely different way to ring this new wire?

Thanks.

[Jolly Roger bus 223]

would be quicker to drop a 3/4 conduit down the back of the bus with something like a weatherhead and then run it in conduit under the bus to where you need it.
running it in the wall really depends on your construction methods?
like in my case i ran my furring strips horizontal and the same thickness as the chair rail and put multiple runs of 1/2" conduit in the cavity so i would have a place to run my wires
protected , can always access the wiring and have spare raceways.
i know hindsight is 20/20.
but this is also my second fancier version of a bus build.
good luck.
i just had a second thought while thinking of my solar panel install.
all of my panels came with splitters/tees for connecting the panels together and only running two wires in from all of the panels.
is yours capable of the same thing?
then you could just add the extra panels without adding another run of wires.

[HamSkoolie]

Yep, feed your existing and add on panels to a combiner box and then use the existing inside the wall wiring.
BUT FIRST
Make sure the total with the new panels remains within the capacity of of the internal wiring (voltage and current carrying capacity)
Make sure your existing charge controllers can handle the additional power (voltage and current capacity) from the added arrays....or be willing to upgrade them.


If the internal wiring can't handle the additional panels this approach will not work.

[Iceni John]

I ran each of my two PV arrays' 4AWG downfeed cables inside the roof's top-hat section steel ribs. I made combiner boxes (each array of four panels is wired in parallel) that are bolted and caulked to the roof, with openings to the inside of the roof rib below. then fed two 4AWG cables down the rib and through 1" holes I drilled through the main longitudinal box-section tube above the windows, and then down through the floor to the charge controllers in the underfloor storage bays. If your bus has continuous roof ribs that continue all the way down to the floor (or below it), then you can use them as ready-made conduits for cables without needing to drill holes through intermediate longerons such as my bus has. I also ran the panels' ground cables through the same rib but on the driver's side instead, and I ran a 1/2" PEX water line up to the roof for the washdown outlets there and a pair of PEX lines for some eventual solar water heating panels. Running cables and PEX lines inside roof ribs completely protects them and hides them from view; I hate seeing cables etc on the outside of the bus!

John

[DeMac]

Originally Posted by Iceni John

I ran each of my two PV arrays' 4AWG downfeed cables inside the roof's top-hat section steel ribs. I made combiner boxes (each array of four panels is wired in parallel) that are bolted and caulked to the roof, with openings to the inside of the roof rib below. then fed two 4AWG cables down the rib and through 1" holes I drilled through the main longitudinal box-section tube above the windows, and then down through the floor to the charge controllers in the underfloor storage bays. If your bus has continuous roof ribs that continue all the way down to the floor (or below it), then you can use them as ready-made conduits for cables without needing to drill holes through intermediate longerons such as my bus has. I also ran the panels' ground cables through the same rib but on the driver's side instead, and I ran a 1/2" PEX water line up to the roof for the washdown outlets there and a pair of PEX lines for some eventual solar water heating panels. Running cables and PEX lines inside roof ribs completely protects them and hides them from view; I hate seeing cables etc on the outside of the bus!

John

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John, that's a great idea for pv, dc & plumbing. Probably ok for ac in metal clad, too. Could add a bushing for protection through the penetrations and an optional air seal around it with plumbers puddy.

The IC factory uses the rib channel as conduit, too.

Stop sign wires

(same from a distance)


Side door alarm, too


Note the rubber grommets at exit, plus flexible plastic conduit for chaffing protection.