Need help with electrical system design

[eidolon]

I'm converting a small cargo trailer to self contained camper and am seeking advice on how to wire things up. Perhaps someone could direct me to links for this phase of the project.

 

[highdesertranger]

We need to know what you want. A transistor radio and a flashlight is a lot different than a rolling power plant. Highdesertranger

 

[bullfrog]

First you need to determine how many watts of power you will need to run whatever you want to run and how many hours a day you will run them in a 24 hour period. This is then used to determine the size of the battery bank which you have several options depending on how much weight you can haul, how much space you have, how much money you have to spend and the type of environment you intend to have them in. Then you can determine the way you will keep the batteries charged by solar, generator, vehicle or shore power. Then we can figure out the most efficient placement and optimal wiring. Several members here can offer assistance and advice but some like jimindenver do consultations. It just depends on you and how much you are willing to take on. There is no one size fits all solution when you are trying to stretch what can be done by creating your own power to meet your needs at minimum cost with maximum efficiency. By the way welcome to the forum!

 

[eidolon]

Thank you. I have all the systems, solar, shore power, freezer, fans, computer, lights, inverter, controller, batteries, etc. Everything is calculated and load balanced, what I need help with is a wiring scheme. AC/DC and three inputs with multiple outputs is a bit overwhelming. Shore power is the only AC 110v input and I'm thinking I should just run that directly to my battery charger and then run everything DC from there. My computers are wired standard household AC receptacles and could be powered from the inverter but that seems inefficient. I also use some power tools that are AC so if I could switch from inverter to shore power when available seems more efficient. Perhaps through a two way switch? Would I need to run inverter and shore power to the switch with one AC output from the switch? My solar charge controller has two input options so an input from the battery on the tow vehicle will be possible, but can I also use an AC to DC charger on the same controller post with the truck alternator? I'm trying to avoid sparks .... thanks for your input.

 

[bullfrog]

First off if your only AC input is through a shore power plug all you need is the appropriate size outdoor receptacle, extension cord, adaptors ( there are several different styles and options depending on where you stay)and a tester to insure you have a good properly wired source of power before plugging in at a campground with a power pole. RV parks generally have a 50amp, 30amp and 2 15amp RV style single phase receptacles. Your DC circuits originating from your battery bank need to be as short as possible to be efficient. I would recommend military style terminals with a short run to bus bars of appropriate size to a DC fuse block, inverter (DC input), charger (DC output)and solar controller battery feed. You do not want your charger to run when your inverter is in use. I would also want to isolate the inverter when plugged into shore power. One way to do this is to use a transfer switch similar to what is used in an RV with a generator. It is a manual three position switch shore power/off/generator (in your case inverter) which makes it impossible for either of the two sources of AC power from being connected to the AC fuse box at the same time. By wiring the charger 120 volt AC input to the connection from the shore power plug that comes through the wall and goes to the transfer switch you will prevent charger use while using the inverter and insure it is on and charging while in the shore power position. If you should ever want to use a generator simply use the outside shore power plug and turn the transfer switch to shore power. To be really efficient I would make battery powered tools and all computers 12 volt chargeable, the less you use the inverter the better, cheaper and more efficient your system will be unless you plan on being plugged into the grid most of the time.

 

[eidolon]

Awesome, thanks for your help.

 

[tx2sturgis]

When starting from scratch like that I would recommend you buy and install an off-the-shelf 120v to 12v converter.

Makes things a lot easier. 

Here is a well-respected brand, there are others:

https://www.progressivedyn.com/power-centers/

 

[eidolon]

Yes, thanks, all in one, I like it! This information is exactly what I was looking for.