RV Electrical System Basics

RV Electrical System Basics
One of the biggest mistakes Do-It-Yourselfers make when troubleshooting or outfitting an RV is assuming that the electrical system is the same as a house. A residential home is powered by 120 Volt Alternating Current (AC) while a Recreational Vehicle utilizes 12 Volts Direct Current and 120 Volt AC power. That means two electrical systems are involved in powering your RV and most appliances utilize both power sources. An example would be a 2-Way Refrigerator, it uses 120V AC for the refrigeration and requires 12V DC for the control board. So let's dive right in, here is some basic information that every RV'er should know.
12 Volt Direct Current
Most people are familiar with 12V DC systems without even knowing it. Your car's electrical system runs off of 12V DC, powered by the starter battery and the alternator. Most of the smaller electrical parts in your RV require a 12V DC power source, like your lights or water pump. Assuming 12V DC electricity acts the same as 120V AC is where most newcomers go wrong. Before attempting any serious install or repair, we recommend doing some research and/or talking with the manufacturer of the component in question. Parts requiring 12V DC power will be powered by your RV Batteries (House Batteries) or a Converter.
120 Volt Alternating Current
Alternating Current is the electricity that you'll find in your house. Most of the big appliances require 120V AC power to operate. Some examples are your air conditioner and refrigerator. Even though these components operate on 120V AC, most require the connection of 12V DC for the control boards. Parts requiring 120V AC power will be powered by an inverter, generator, or by plugging into an AC power source.

A converter takes in 120V AC and converts it to 12V DC. Converters are common in most RV's, typically paired with the distribution panel or found near the exterior 120V AC inlet.
An inverter takes in 12V DC and converts it to 120V AC. Inverters are less common than converters, but are typically found in RV's equipped with solar panels.