When you first get into RV camping you go to the dealer and they show you all of the wonderful options you can get: Outside kitchens with a refrigerator, outside television, dual source water heaters, and so on. What they don’t tell you is how your RV electrical systems work and how much each item pulls in amperage or how you probably won’t be able to run all these items at one time without tripping a breaker or causing damage to the wiring depending on what amperage connection you have.
RV Electrical System Basics
So let’s start with electricity basics. Most RV’s come with either a 30 or 50 amp electrical plugin. An amp is a measure of electrical current. To calculate current draw you divide the wattage by the input voltage of the item. RV’s setup with a 30 amp connection have one line at 120 volts allowing a maximum usage of 3,600 watts. RV’s setup with a 50 amp connection have a 240 volt connection by way of two 120 volt lines coming in 180 degrees out of phase of each other.
The power with the 50 amp comes in to your power panel on two separate busses tied together with a double pole 50 amp breaker which will give you 6,000 watts of power to each side of the connection or a total of 12,000 watts of power. The 50 amp connection should be more than enough to meet current demands in new RV’s.
Our RV Electrical System
We purchased our trailer new in 2016. I felt we were OK with the 15,000 BTU air conditioner and did not opt for the 2nd unit. There was also an option to prep for the 2nd air which upgraded the trailer to 50 amps. At the time this didn’t seem necessary so we passed on 50 amp also. Looking back I should have done my homework as this small upgrade would have made things less complicated.
Don’t get me wrong, we are able to use our trailer and all of its options but we have to be aware of what we are running and turn off some items at certain times in order to run others. This became apparent from the random breaker trips we would have while camping.
So let’s look at some of the items in the trailer and the power they consume:
Power Converter: 1 amp
Indoor Refrigerator: 3 amps
Air Conditioner: 16 amps
Electric Water Heater: 12 amps
Microwave: 8 amps
Outdoor Refrigerator: 2 amps
Right away with just the built in items we are pulling 41 amps.
Now add other items commonly used: coffee pot 13 amps, hair dryer 13 amps, etc. We have very quickly run out of juice.
We quickly learned that we had to manage what we operated to insure we didn’t overload the system. If we have the A/C, the water heater, and the refrigerator operating we are pulling 29 amps so we know if we need to run the microwave we turn off the water heater. If we are running the microwave and coffee pot in the morning, we turn off the AC and the water heater.
It becomes 2nd nature once we learned how much each item pulled and what the trade off needed to be although it would be nice not to worry about such things. If we had opted for the 50 amp connection I wouldn’t have had to deal with this and probably wouldn’t be posting this.
Safeguarding Your RV Electrical System
I highly recommend purchasing an EMS(Electrical Management System) to protect your RV Electrical System. Not only does it provide protection from power surges that occur from storms and power supply issues, but it also protects your rig from high and low voltages that happen from time to time.
If the system detects high or low voltage, it will cut power the the RV then restore power once the voltage returns to optimum levels. It also has a timer circuit to assure it does not restore power within a couple minutes of shutting down as this is harmful to your air conditioning compressor.
Ours also can detect high temperature at the plug and shut down if it detects overheating. My favorite part is it has an LCD display that shows the current line voltage then the power consumption in amps. Pretty handy if your not sure how much your rig is pulling. I went through and turned on our items one at a time to determine how much each item was drawing.
We use the Surge Guard 34930 which is for 30 amp systems and they also have the Surge Guard 34951 which is for 50 amp systems.
Unfortunately we continue to use more and more power in today’s rigs and several campgrounds have yet to fully upgrade to 50 amp service so you also need to be aware if you are in a rig with 50 amp service and have to use an adapter to plug into a 30 amp connection that you really have to keep an eye on what items you can run as you can now only run 3,600 watts versus the 12,000 you normally would.
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