The RV Electrical system can make the life of the camper almost as if you are at home. There is a great variety of fitouts available, though most need to follow some basic guidelines. Beware that in some countries you need to be certified to do modifications to the high voltage part of your vehicle if present. We have build several motorhomes ourselves now, and we will share some of our experiences of what does and doesn’t work.
The general recommended setup is to have a separate batterie bank (1 or more) called the “house battery” to supply the living part of your RV of sufficient power. It is important to make your RV as energy efficient as possible because the specific deep cycle batteries are expensive and have a certain lifetime so they will need to be replaced regularly. So start by thinking what you will need power for and for how long without charging. In travel trailers that will as of use mostly be a lot longer then in the motorhome where the house battery is charged while driving. If you reallly need quite a bit of power or you need it for a longer period of time, solar panels or a generator could be te answer for you.
A few basic rules:
- The house battery needs to be seperated from the start battery so you can start your engine after partying the night before in the back. While years ago you had to buld your own system with either a diode or a relay that switched the charging power to the house battery once tge engine was running now most used at the moment is the VSR or voltage sensitive relay. This device switches on when the voltage at the engine end is sufficient to start charging the second batterie. Voltage sensitive relay is availble in both 12 and 24 Volts. Attention: make sure you don’t run the engine while on the grid as the VSR could interfere with the conventional battery charger. Specail switches are available to automatially choose one or the other. Some VSR’s also allow you to bridge them so you can use your house battery to support your engine battery.
- I always put a fuse early in the circuit: in case a high amp wire gets damaged nothing will be fried or damaged. I also use several isolating switches so I can seperate circuits from eachother: a little investment here can save you a lot of headaches later. Make sure your wiring is accessible, i don’t like the setup where all wiring is hidden in the inside of the walls, it makes changes and repairs so hard to do!
- I try to make all my connections in one place, and reserve a space either on a lpiece of plywood or to make it fance in a wiring box to do all my connections to te different appliances. This switchboard contains a few bush bars and fuseholders. Please remember to name all connections so it will be easy to do troubleshooting.
The high voltage system (240V or 110V depending on where you live)
The high voltage part of your motorhome should definately be installed by a qualified professional who knows what he is doing. If you have the double option of connecting to the grid and an alternator special care needs to be taken either physical or electrical that both cannot be connected at the same time to avoid fireworks! In any case it is an absolute necessity to install an RCD, this device swithes the hi