Hi folks,
I just bought a 6x12 cargo trailer to turn into a camper. Thought it would be fun to share it here. There will be lots of wiring done, so I've posted in Mikes forum. This is probably a smaller setup than what most people here have, but I've been tent camping my whole life, and am just now upgrading to a very simple camping trailer. So hopefully you all will find this process interesting.
I've attached a picture of my truck and trailer setup for now. I'll have lots more to share soon. 🙂
So I have a few goals for this trailer; some may be more challenging than others. One is a weight limit of 2,000 lbs. Another is to have an air conditioner for the really hot weather we occasionally find ourselves in. A third goal is to be able to camp off-grid for short periods of time. For that, I'll be installing a solar array and a battery. Apart from the electrical system, I want to keep the trailer fairly simple. As a result, the trailer will not have a few things that most RVs typically come with:
-no bathroom/shower
-no black or gray water tanks
-no stove or propane tanks
The kinds of things that people do that would require these things, we'll be doing away from the trailer. The one thing that is top priority for this build though is the A/C. My wife and I both get absolutely miserable in the heat. Fortunately, our tiny trailer will allow us to use a small 5,000 BTU window unit instead of the big RV roof units. I don't plan to have it hanging outside the trailer though. I'll show how I plan to install it later.
I found some solar panels that are just the right shape to fit 10 of them on the roof of the trailer. This will let me have a 1,000 Watt array that could deliver up to (but probably less than) 3,000 kWh per day. On a bright hot day, that should be enough to keep the battery topped up, and run all the electrics that I plan to install. More on that later.
I've never heard anyone complain that they have too much solar, so I've dedicated the whole roof to it. The vents will be on the side of the trailer instead of the roof. I'll also have a power inlet for grid-power when available, or a generator if we really need it.
Attached is a "floor" plan of the roof. It's to scale, so you can see how the panels will just fit the 6x12 area. I'll have to build my own mounting bracket, but that's ok.
I've spent a long time on the attached picture, and it's still a work in progress. But here is my electrical diagram for the trailer.
Lots going on in the diagram, and it's not a professional one with all the proper symbols, but it lets me see what I'm planning to do. Purple things use power, green things provide power, and blue things are just various components. Red wires are DC positive, black wires are AC hot neutral and ground. I've omitted things like DC negative wires and junction boxes for simplicity.
The A/C and mini fridge will be the only devices running of an inverter if there is no grid power, so that circuit is the only one with an isolation switch. I've done my best to keep as much as possible powered by DC. I know they make fridges that run on other things besides AC, but I don't like them. I've also taken into account the peak current draw on the fridge and A/C. I just got enough parts to test out the battery/inverter/appliance system soon.
To reduce the current running through the DC system, I've opted for 24V instead of 12V. A few devices are still 12V, but they can be run off a voltage regulator easily enough.
I estimated the power usage as best I could using lots and lots of math. I'll spare you all the details, but the battery and solar setup should be plenty to run the electrical as long as we use it conservatively.
I've made a floor plan of the cargo camper. It's all to scale except the head board. It will have some gadgets built in, and I still need to figure out exactly how I want them positioned. Also, I've not decided on the size shape and locations of the windows yet.
First thing I plan to do is take out all the plywood walls and floor. I'll inspect the wiring for the driving lights, and get the floor all sealed up good, and maybe insulated. After that, I'm not sure of the exact order of things, but I'll be installing insulation and wiring for all the new stuff I plan to build in.
I've got all the cells tested now, for the battery I want to build. I've also got the inverter, so I hope to do a test of the inverter and battery to see if they can actually run the A/C and fridge at the same time.
My pickup truck has a towing weight limit of 2,400lbs. The limiting factor turns out to be the clutch. I always thought manual transmissions were better for towing, but I guess I'm wrong. After driving around a bit with stuff in the trailer, the truck actually does really well, so I'm not too worried as long as I keep the weight down.
Anyway, so I'm trying to keep the weight of this little camper at 2,000lbs or less. Since I won't have any big water or propane tanks installed, I think I can do that. The advertised weight of the trailer is 1,100lbs, so I have 900lbs to work with.
Probably best to weigh it myself though to be sure. The advertised number is probably just an estimate. So I plan to weigh the trailer before and after the customizations and see what it ends up weighing. I have a slick method of weighing it at home using a bathroom scale and physics.
In the mean time, I've put together a list of weights and costs for all the parts I'm planning to use. It's still a work in progress, but it gives me an idea on how I'm doing. The green stuff are actual real-life values. The yellow stuff is what I've gotten from advertisements and spec sheets. The white ones are wild guesses. And you can see there are total blanks where I haven't even guessed yet, LOL.
Over time, this table will become more filled out and accurate, but attached here is what I have at the moment.
New video:
Just me talking again. This time I'm giving a brief overview of how I plan to do the electrical. I've updated my wiring diagram too, based on some new stuff I've learned lately about my battery and solar panels in general.
I've been thinking about grounding lately. Specifically, what to do with the ground wires that lead up to my isolation switch, and the ground post on the body of the inverter. I've made a diagram showing much more detail of the AC side of things to maybe help me figure it out.
So here's what I think I know:
-If the trailer is connected to a service connection somewhere, there should be a physical ground rod buried in the actual dirt somewhere.
-If the trailer is connected to a generator, there should be a bond between the ground and neutral. Either inside the generator or via an adapter.
-If the trailer is connected to nothing, there will be no ground connection to either neutral or earth.
-The neutral bus bar in the breaker panel needs to be isolated from ground.
-The trailer body needs to be connected to ground.
Here's what I'm not sure of:
-The solar panel frames (being aluminum) and mounting hardware should be grounded to the trailer body?
-The solar panel frames should also be grounded to the inverter via the ground connector on the inverter's body?
-The inverter body should be grounded to it's AC output ground?
-All the ground wires meeting up at the isolation switch should be connected together?
Vaguely related: I plan to use GFCI breakers, or maybe the GFCI/AFCI combo breakers.
Anyway, does it mater that sometimes the trailer will be connected to a ground rod, and sometimes just boded to neutral, and sometimes neither?
Hi Michael, just a little housekeeping note:
When you want to place images into a forum post, you can upload them directly to our site. This will most likely speed delivery of the images to readers as we cache our content around the internet.
Second is when you're posting a link to an image or video, you can just paste in the link and our forum software will automatically embed the image or video into the post. We support YouTube, Vimeo and many other services.
Great work on the trailer, can't wait to see what's next!
Kim
Thanks Kim, I'll keep that in mind. By adding the picture directly to the sight, do you mean attaching? If so, I'm not sure how to put the images where I want them, or how to add more than one per post.
Speaking of images, here's an attached one of my updated grounding diagram. Based on everything I've learned so far. I think that's going to be all for my grounding research. In other news, I got my solar panels! I made a short video of my solar plan and unboxing and testing a few of the panels.
This weekend is the last cargo run before the trailer gets gutted and rebuilt. From there, progress will only be limited by funding, weather, and how much energy I have between this and other projects. 🙂
Creating a camper from a cargo trailer necessitates taking measurements, drawing a plan, locating and purchasing necessary components, and finally installing each component. It may appear to be a difficult task, especially for novices.
Here it is July, and it's still raining where I live. But I did get a box built for my battery.
We're still cleaning out the carport so I have room to empty out the trailer. Can't really work on it until it's empty. I'm hoping this week I'll be able to start moving things.
It's weird, I don't remember writing the post from May 13. I've been trying to only post things specific to my project here. Maybe I only posted half of what I meant to. Well not much has happened lately due to the weather anyway.