RV Basic Electrical Systems

When I first got my RV I was so in the dark about RV electrical systems, converters vs inverters, DC vs AC but after so much DIY work and research it makes a lot more sense. I want to help you understand what the heck all these things are and how they all go together differently and the purposes for each. Be sure to learn more about the basics of RV solar regarding panels and charge controllers in this affiliated post, part 1 of 4.

CONVERTER vs INVERTER

RV’s electrical systems use DC power inside for lighting and some pre-installed appliances like TVs whereas houses traditionally use AC. If your RV comes with a TV, you’ve probably noticed its plug looks like this or something that you would plug into a cigarette lighter in your car.

Look at a standard plug on most devices you plug into your home, like a cell phone charger or lamp and you’ll see an example of an AC plug (at least in the US).

Converters

Most houses are hooked up to a municipal power source which is always AC. So when you plug your RV into shore power such as an outlet at a camp ground or an outlet at a house, you’re accessing AC power. However, your RV needs DC power to run its pre-installed lights and appliances. Therefore you must convert that AC shore power to DC. That is the job of a converter.

Most RVs come standard with a converter/charger. The converter takes AC power that is fed into the RV from the shore power source and converts it to DC power. Usually converters are also called converter/chargers. They also charge your house batteries.

When you are not plugged into an outlet and are “off grid”, your RV gets power from the house batteries. The house batteries produce DC power unlike shore power from the city providing AC power so no conversion is necessary. Therefore when you’re using your batteries, you aren’t using your converter.

If you are running off your house batteries and you RV only has a converter, you can not run AC appliances. You can only use appliances that have a DC plug. So, if your RV only has a converter and you’re out travelling around and stop at the store and want to make a smoothie or charge your computer, you can not. But you can plug an appliance into your DC outlets if you have a cord for them, such as a cell phone charger.

Inverters

So how do you run an AC appliance while running off the house batteries? – Something that would be very important if you want to do more than just run lights and watch TV while travelling. You can either use your generator as a power source or you get an inverter.

You could either get an inverter to power your entire RV electrical system or you could get a small portable inverter that plugs into the cigarette lighter or DC outlet in your RV that has an AC plug or two that you can run an AC appliance off of. However, a small portable inverter will only let you use that one outlet on the inverter and if you need it in another part of the RV and it’s cord isn’t long enough to reach, then it will limit where you can use appliances. For example, you may have to bring your blender to the cab area of your RV.

What an inverter does is it takes DC power provided from your batteries and converts it to AC to allow your AC power outlets in the RV to work while you are off grid and relying on battery power as well as all you DC lights and appliances. Many installed inverters will also keep your house batteries charged just like converters do.

Sine Waves

There are two types you will find with inverters. Pure sine wave and modified sine wave. Modified has a squared wave is not ideal for regular full time living because it interrupts charges like on electric tooth brushes and some larger appliances so they don’t work or charge as well. However, they’re cheaper and great for the weekend warriors.

The pure sine offers an uninterrupted steam of power and a must for RV residents like me.

If you’re interested in going solar in your RV you’re going to need an inverter. Converters will only work with AC as its power source.

By the way, I used to have a converter/charger in my RV and it buzzed constantly. I learned that some technicians in the industry call them buzz boxes. For the first few weeks of living in my RV, I thought I was going to go mad because I would always be hearing a constant buzz. Not to mention the charger part of it didn’t work. Anyway I upgraded to an inverter and so happy with it and to now be going RV solar living!

From the series: