RV installation

System

I have been doing a lot of research regarding solar power, and being independent as far as a RV is concerned. I am about to test this out on my small travel trailer, and if all goes as planned, I will invest in a package for my fifth wheel. As I said earlier, while researching installation instructions from numerous sites I have been on, one thing always stands out to me. Instructions state to mount the solar regulator/controller as near to the batteries as possible, but then instruct to route wiring through the fridge vent, and mount there. This seems to be a conflict of information.

Does anyone have any recommendations on routing wires into the trailier, without using the fridge vent (perhaps a link). I would think the most direct route possible would be the way to go to avoid voltage drop.

Thanks

Cariboocoot

Re: RV installation

Welcome to this forum.

Installations are highly individualistic. However, I doubt anyone here would recommend running a wire through a vent or via any other such method which could result in pinching the wire or otherwise compromising the insulation.

As a rule, cables between batteries and charge controllers or inverters should be kept as short as possible because this is where the most current is flowing. The shorter (and larger) the wire the better for handling the Amps. Obviously there's a need to balance that with the practical side of where things will actually fit.

So there's this other rule: make the longest runs on the highest Voltage and/or lowest Amperage part of the system. Depending on exactly what the install is, this could be the wires from the PV's to the controller (as it is possible to run higher-than-nominal-Voltage array and down-convert through an MPPT controller for proper charging).

Most people would agree that wires that are exposed, either inside or out, be run through conduit to protect them from the ravages of weather, UV, and abominable beasts (whether two-legged or four-legged) that like to damage wires. If the RV unit has no convenient "wire through" access already, that means drilling holes through, using weather-tight equipment, and sealing up around the edges. Here's a hint: holes through a flat roof are the most likely to leak no matter how much silicone you put around them. Dropping the wires (in conduit) over the edge and coming in through the side is safest for keeping out the water.

I'm sure others here will have more to contribute. There are members who do have RV's and have done the solar install themselves. Like Kamala, who seems to have gone missing of late. I hope that nasty mid-west weather didn't wash him away; very bad flooding out there this Spring.

BB.

Re: RV installation

Here is a nice thread with video from Kevin in Calgary Canada that shows designing and installing solar PV in a small RV trailer.

-Bill

PhilS

Re: RV installation

I'm guessing you see "run wire through fridge vent" because many RV manufacturers pre-wire for solar and use that vent. On ours, removing the vent cap gave access to those wires. Any other way you could get decent gauge wire to the roof panels is certainly acceptable. Also, running the wires that way eliminates putting them through holes in the roof which, as said, is a potential leak.

Phil

bluewickedburner

Re: RV installation

My take.

First, since we're not talking about 300 meters of wire just go big. So you might spend $100 on wire, AND? I put this into the same category as putting diesel or gas into your fuel tank. Do you fill it up or put in enough to get you there plus another 10 miles? New tires or just enough to get another thousand miles out of them? Think about it. Smaller no, larger-yes.

Properly sealed, holes no matter where you put them will not leak. The whole point being "sealed properly." With both surfaces cleaned well (roof and whatever is going on it" and sealed, it isn't going to leak. 3M makes some sealing tape that if you just follow the directions, will not allow a leak. A water leak is like a bad wire connection, both result from not doing things right.

When you seal a hole, wait the proper amount of time before even touching anything that goes through that hole, let it all setup. Moving it before the sealant sets almost guarantees a leak.

The fridge vent. Nothing wrong with it. In many cases it is the shortest and easiest run pathway.

WARNING: Running a wire down off the roof onto the side and then going into a wall is dangerous. Much more likely to scrape a branch or something and rip everything off. Loose a mirror, livable. Let a branch catch that wire and just park and put out the for sale sign. Don't do it for your own sake. Yeah, you can hit branches on the roof too but lots of things will hit first and usually you are going slow. There is a reason no one puts wires on the sides of moving objects like cars, trucks and RVs.

Then again, there are people that hang their feet from windows and let their kids do the same with their heads. Culling the herd.

Distance from batteries to controller. Back to big wire. Leave room for margin. Why run #4 wire when you can run #0 or #00? We're not talking about running 150 amps through anything on an RV right? Yes, closer is better but don't get so wound up about some length there that your install gets complicated.

You'll see folks that spend big dollars on charge controllers, panels and then start counting pennies on wire, factoring to the inch the losses of one gauge over another. Please.

Do yourself a big favor. Put things where you want them, they are safe to be and easy to get to in case something goes wrong or needs to be replaced.. Run big wire (you only buy it once right?) and get happy and use the solar.

vcallaway

Re: RV installation

My refrigerator vent has pretty much become my cable run. I used 4ga wire to go from combiner box to charge controller.

My wifi, and cell antennas are run through there as well. Just too darn convenient and accessible to NOT use it.

Spools of 4ga wire can be picked up fairly reasonable from car stereo installers. Got my fuse holder there as well.

Undersized wiring is like trying to drive with the choke closed.