Why Do I Keep Popping Breakers In My RV?
RV electrical systems are much like power systems in sticks-n-bricks homes, with a 120 volt AC (alternating current) system and connections running through a breaker panel. These breakers will trip or turn off to prevent damage. When they do, the fuse must be replaced. The AC system powers things like your microwave, television, and all the outlets in your rig.
Why does a breaker trip?
First, understand that breakers and fuses are there to protect your RV and the appliances that are connected to them. There are two primary reasons a breaker will trip:
- Insufficient capacity
- A short circuit
If a breaker fails to trip, the appliances plugged into that circuit could be damaged. Worse, a short circuit in the wires that make up that circuit will overheat, melt the insulation covering them, and cause a fire. The majority of RV fires that you read about were caused by this scenario. That’s why it is so important to keep fire extinguishers available.
What is “insufficient capacity”?
All breakers are rated for a certain amperage. In the image of the breaker panel above, you can see that most of the breakers are 15 or 20 amps. The two in the middle that are 50 amps are the breakers from the two legs coming in from shore power. All the AC power goes through those.
Smaller circuits are tied to one of the 15 or 20 amp breakers. This creates a safety redundancy. The 50 amp breaker on the left provides power to all the smaller breakers on the left. And vice-versa for the 50 amp on the right. If the total combined power draw of appliances or devices in use exceed the amperage rating of the breaker, that breaker will trip.
You may notice that, on the left, the smaller breakers add up to 70 amps on the left and 100 amps on the right. That’s more than the main 50 amp breaker! There are two air conditioners on the right side of the panel and a fireplace. It’s unlikely you would use those at the same time.
The 50 amp minimizes the total power output. If you ran the full 70 or 100 amps, divided over the smaller circuits on one side, you would trip the main 50 amp breaker on that side. That would shut down all of the smaller circuits on both sides because the two 50s are physically connected to shut everything off to protect your RV.
Determine your RV power needs
To determine what your power draw is for an individual circuit, you will need to do some math. Check out this great RV LIFE article that explains this in detail. If you have a 15 amp circuit and you plug in and use devices on that circuit that use 20 amps combined, the circuit will trip, as it should.
Testing your capacity
Sometimes it’s a matter of, “Oops, my rig can’t handle a hair dryer and the coffee pot at the same time.” The tripping breakers will teach you this very quickly.
Reset the breaker by flipping it completely off (it should wiggle loosely when tripped) and then back on and use less power on that circuit. If it resets again, test your appliances or devices in another outlet. If that circuit trips, you need to investigate what is wrong with the device or determine with its label if it uses more power than you have available.
You could replace a breaker with a larger capacity breaker; however, you should never do this. Breakers are rated for a certain amperage draw, as well as the wires leading up to them that make up the circuit. Placing a larger amp breaker will cause more power to flow through. If the wires aren’t rated for more power, you will easily start a fire that will be hard to find.
What is a short circuit?
We use the term “short circuit” to imply a positive and negative or ground or neutral wires. They come together in a bad way, but that’s exactly what your blender does once you plug it in and turn it on.
Bringing together the positive and negative power circuits causes “work” to be done (turning the motor), and this utilizes the power correctly. We could call this a “controlled short circuit”. When the switch is turned off, the power remains separate.
When the positive and ground wires come together without something to utilize the power, this is what we call a “short circuit”. Or, if a positive wire comes loose from any connection and touches a conductive surface, like the metal in your RV, this also causes a short because that metal is considered a “ground” and supplies the other half of the circuit.
When a short happens, it will always generate heat. Therefore, most short circuits result in fires. If a breaker continues to trip repeatedly (or a fuse continues to burn out after replacement), a short circuit is almost always the cause. In this case, leave it turned off and consult experienced assistance.
Hire a professional
Electrical power circuits are dangerous! Sometimes a breaker or breaker panel can malfunction. If you are not an experienced electrician, have qualified personnel diagnose and correct any issues in your electrical system.
When a person gets “shocked” by electricity, this is a prime example of a “short circuit”. The human body does not have the capacity to handle voltages over a certain threshold.
As a child, you may have put your tongue to a 9-volt battery and got a tickling tingle. There is a big difference between 9 volts and 120 volts. A defibrillator can jump start a heart, but it can also stop one, too. Don’t take chances!
Track your RV maintenance & repairs
Make sure you keep track of all your RV maintenance and repairs with RV LIFE Maintenance. Not only can you keep all of your documents in one place, but you’ll also receive reminders when maintenance is due to help you avoid costly repairs and accidents.