RV Electrical

Before we go into the nitty gritty stuff, I wanted to highlight electrical safety first because any electrical hazard (open wires, short circuits, etc.) can cause burns, shock and electrocution. There are a lot of safety tips online, but some of the most general reminders I’d like to share are:

  • Always make sure that the power source is off/unplugged, before working on any part of the electrical system
  • Never assume that a wire is safe to touch, since some electricals can still carry a charge
  • Never overload a circuit (multiple extension cords, etc.)
  • Keep the area near any electricals dry, because water, wet hands, or even high humidity can increase electrocution risk.

An RVs electrical system can seem overly complex. However, the electrical system is easy to understand once you know a few basic things. RVs (trailers and motorhomes) have 2 separate electrical systems. A 12-voltDC coach/trailer system and a 120-voltAC coach/trailer system. Motorhomes have an additional electrical system, which is the 12-volt DC of the automotive system, that feeds into the coach’s 12-volt DC batteries and is separated by way of an isolator. The isolator only allows 12-volt power generated by the alternate or to flow one way, thus protects the automotive battery from being drained by power use in the coach.

Batter Isolator

The AC system only has power to it when plugged into shore power unless your RV has an inverter. The DC side, which is connected to your batteries has power all the time if the master cut off switch is on. Some items in your RV Run on DC only and some only on AC, while some run on both AC and DC depending on what power is available. Here’s a list of items in an RV and what type of power it uses.

ItemDC powerAC power
LightsX 
USB plugX 
WIFI BoosterX 
Cell BoosterX 
TelevisionX 
Satellite SystemX 
Furnace Propane (fan)X 
Tri-fuel fridgeXX
Hot water systemXX
Propane StoveX 
Induction Stove X
Microwave X
Electric AwingX 
Washing Machines X
Dryers X
Air Conditioner X

All RV electrical systems will also have a breaker panel for DC and AC, a converter to convert AC power to DC power to charge the batteries, one (or more) 12V batteries. If the RV has solar panels, there is an additional regulator that is connected to the RV batteries.

How Does Your RV Electrical System Work 1

An RV’s AC (Alternating Current) System


The AC electrical system in an RV is typically powered by an external source. All RV’s that have power will at a minimum have a 30-amp plug, while larger motorhomes and trailers will have a 50-amp plug (Class A motorhome, Super C motorhome, 5th wheels and larger travel trailers). While one can plug their RV into a homes 120-volt power, with an adaptor or dog bone, there will not be sufficient power to run all your appliances that requires your full 30- or 50-amp power.

RV park AC pedestal power

pedestal breakers are usually designed with a +/- 20% tolerance. So, if a regular 30-amp outlet supplies 3,600 watts (30amps x 120v), the pedestal breaker could still trip between 2,880 watts and 4,320 watts (these values are the +/- 20% tolerance I mentioned earlier).

Once you plug in your RV to connect to shore power (AC), the flow of electricity goes as so:

How Does Your RV Electrical System Work 2

Pedestal >(Pedestal Breaker)>(Surge Protector)> RV Breaker Panel >AC appliances (microwave, Air conditioner, electrical plugs)

This flow would be similar if you plug-in your RV to a generator. Large RVs may come with a pre-installed propane-operated generator, but if you do want to purchase one aftermarket, we’ll discuss this later on in the article HERE.

An RV’s DC (Direct Current) System


DC power is the primary power that is used in an RV. The DC power supply in the RV is powered by Battery banks or battery. The voltage is 12 volts. Most RVs today are still using lead acid batteries to supply power as it’s the cheapest. The next step up is AGM batteries an finally Lithium batteries, which actually have been dropping rapidly in price will probably overtake lead acid batteries in RV use. The Batteries hook up to the Fuse box, where DC power is split up to the different appliances and lights in your Rig. The fuses protect the entire system from possible shorts and damage to your DC power system.

electrical panel

Pedestal >(Pedestal Breaker)>(Surge Protector)> RV Breaker Panel > RV Converter > 12V battery bank>12V fuse box > (lights, USB outlets, WIFI, satellite tv, appliances that need 12V to ignite)

Many New RV’s today come with Solar Panels, they are DC power and are setup with the solar panels generate energy,which feed into a voltage regulator and then into the RV batteries for storage.

Is An RV Surge Protector Necessary?

I didn’t think that not having a surge protector would be an issue until I melted my plug that I had my RV plugged into. A surge protector is highly recommended to protect the RV’s electrical system in the event of a power surge or the variation in volts that come from a campgrounds power. Surge protectors for an RV come in 50 amp and 30 amps will tell you if there is power, an open neutral, an open ground, or reversed wiring. RV Surge protectors last for 2 to 5 years depending on the use. A surge protector is the minimum protection for an RV’s electrical system.

How Does Your RV Electrical System Work 3

A step up in protection is an EMS(electrical management system) device that will surge protect and regulate the power for all the electrical systems plugged into the RV such as computers, monitors and other sensitive electronic devices.

Can I Use A 50 Amp Surge Protector On A 30 Amp RV?


Using a 50 am surge protector on a 30 am RV, may not provide the protection that a 30-amp RV would require. If your RV uses 50-amp power, then you would purchase 50-amp surge protector. If your RV uses 30-amp power, then you would purchase a 30-amp surge protector.

 
As an example, if your RV uses 50 amps and are at a campsite where the power 30 amps, then you would just add the appropriate adaptor to go from 30 amps to 50 amps and then plug your 50-amp surge protector into it. There is no need to purchase a 50-amp surge protector and a 30-amp surge protector.

RV Surge Protector

Is An RV Battery AC or DC?


Although RV’s use AC power and DC power based on what is available. External power is always Alternating Power or AC. While RV batteries are Always Direct Current or DC power. The standard power is 12-volts in an RV. This is achieved by using 12-volt DC marine batteries set up in parallel or at least 6-volt batteries set up in a series and possibility parrel.

How Does Your RV Electrical System Work 4

The most common type of RV batteries is lead acid and gel, although lithium-iron batteries are increasingly being used due to the decrease in prices in recent years. The DC power from an RV battery runs lights, USB plugs, and Fridges. If you are interested in knowing more about the different batteries for RV’s check out this article that goes into detail on each type.

Basic RV Electrical Terms

I’ll run through a few basic terms and acronyms we’ll be using throughout the article which will be helpful, especially if you’re new to this, or would just like to recall some of these terms you probably went through in school, but never really took it seriously, until now.

  • AC = Alternating Current; current changes directions periodically (same as what you’ll use at home)
  • DC = Direct Current; electricity only flows in one direction (same as how you power your car)
  • Amps = measures the speed of the electric current (think of it like the water flow)
  • Voltage = measures the electromagnetic force to move one ampere (think of it like water pressure)
  • Watts = Volts x Amps (power released per second)
  • Parallel wiring = Doubles the Amperage, but voltage stays the same
  • Series wiring = Double the Voltage, leaving amperage the same
  • UPS = Uninterrupted Power Supply
  • Watt hours (Wh) = daily watt hour consumption

= watts of the appliance x hours used per day
= watts of the appliance x minutes used per day ÷ 60 minutes
*Some appliances are only used for a fraction of an hour or minute per day. So if you need to compute for the Watts of a 1100W electric kettle for 10 minutes per day.

I’ll be mentioning these terms a lot in the article, so if you get confused, don’t hesitate to go back to this section.

What Is The Standard RV Electrical Hook Up?


The available RV electrical hook-up service, or pedestals, in an RV park or a developed campground would be:

  • 15 or 20 amp – this is the standard looking household plug
  • 30 amp
  • 50 amp

The most common pedestal plug-ins in RV parks would be a 30-amp service. While some campgrounds only offer 15 or 20 amp. An adaptor is needed to convert the your RV’s plug to the services provided.

Larger RV's usually require more electricity, as it has more appliances in it that need to be powered. If by chance that there isn’t a 50amp service available on the pedestal, you can still plug your RV into a 30amp outlet, but you’ll need to use less of your electrical equipment onboard. If possible, use shorter adapters and extension cords, to avoid voltage drops.

30 amp plug

30 amp plug

50 amp plug

What Is The Difference Between A 30 Amp And A 50 Amp RV Hook Up?

The primary difference between a 30-amp and a 50-amp RV hook up is number of volts that one provides over the other. A 50-amp service provides 3.3 times more volts and watts than a 30-amp service can provide, thus allowing for RV with 50-amps to run 3 times more appliances than a 30-amp Rig. This chart breaks down the details of 30-amp vs 50-amp power.

Power TypeProngsVoltsWatts
30-amp3 prongs30 amp X 120-volts3,600 watts
50-amp4 prongs2 X 50-amp120-volt hot wires = 240 volts12,000 watts
How Does Your RV Electrical System Work 5
How Does Your RV Electrical System Work 6

RV’s with 30-ampsare typically in smaller and don’t require as much power as a larger rigs, typically there’s one Air conditioner, microwave and power outlets.

Large RV’s with 50-amp AC power supplies are broken down into two 50-amps at 120 volts or also known as a 120 split phase service. This means that the electrical box in the RV is a split to have 50 amps for 2 different parts of your RV.A total of 12,000 watts of power allows for home appliances, multiple air conditioners units and many more appliances that can run on AC power. Here is an example of what a 50-amp box would look like.

Appliance 50-amp 50-amp
Air Conditioner 1 X
Air Conditioner 2 X
Microwave X
Fridge X
Plugs X X
Television X
Washing Machine X
Dryer X
Electric Water Heater X

Can I Plug My RV Into A 120v Outlet Or Into A House?


Plugging an RV into a house 120 outlet will not do any harm to the Rig. A houses 120 volts will just not be enough to power all the items in the motorhome or Trailer. People plug their RVs into their house power with an adaptor, that goes from 30 or 50 amp to 120 plug. Typically experienced RVers do this 4 to 24 hrs before they head out on a camping trip, by cooling their Fridge with AC power prior to camping, there is less chance of food spoilage.

120 amp plug

Can I Plug My 30-Amp RV Into A 50-Amp Service Without Damage?


When you pull your Rig into a camping spot and they only have a 50-amp service, and your RV is only 30 amps. If you have an adaptor to go from 50 amps to 30 amps, your RV should be and not suffer any kind of damage. The 50 amp to 30-amp adaptor uses the hots on the 50 amp and the ground so your RV will not draw too many amps and damage your RV.

How Does Your RV Electrical System Work 7

Are 50 Amp To 30 Amp Adaptors Safe?


50-amp male to a 30-amp female adaptor, are safe to plug a 30-amp RV into a 50-am power source. This does NOT cause serious harm to your RV’s electrical system as your RV will only draw the necessary power use.

50 amp to 30 amp Adaptor dog bone

Can I Plug My 50-amp RV Into A 30-amp Service Without Damage?


Plugging in a 50-amp camper to a 30-amp power sources will not harm anything if you do not try to turn on all your appliances such as all your Air conditioners, hot water system, refrigerator to all run on AC power. Running some items such as Air conditioner units on low amperages can damage the motor. Some appliances will have to run off propane, such as the Refrigerator and hot water system. An adaptor will be required for your RV’s 50 amp plug to go to a 30-amp plug on the pedestal.

50 amp to 30 amp adaptor

50 amp to 30 amp adaptor

How Does An RV Converter Work?


An RV converter works by turning Alternating Current (AC)to Direct Current (DC) by way of a transformer. No different than your cell phone charger that plugs into a wall outlet with 120 volts. The AC power that is used in RV’s is 50-amp, 30-amp and 20-amp with 120 volts. While the DC power in RV’s are 12-volts. The typical converter produces 30 to 40 amps DC amps per hr.

RV power Converter

How Much Power Do I Need For My RV?

To determine how much power, you need for your RV, you’ll need to diligently list down everything, and I mean EVERYTHING, that consumes power in your RV. Also take into consideration how much power exactly each appliance needs, if you’ll be using all these appliances at the same time, and also how long you’ll be using it. An example of this would be if you are running your RV fridge, together with your AC or heater, while the lights are on and you arecharging your phone, while someone watches TV and/or someone else needs to use a hairdryer. Also note that there are appliances that take a while (and more power) during start up and will drain more power before it stabilizes and runs on its average power consumption per hour.

As you’re listing down all the items that require electricity, there should be a label on the unit (usually in the back, or underneath) that will show the rated voltage &maximum amperes it needs to run. Some labels will also include the watts (so you don’t need to compute for it). Following the formula to compute the wattage will help get exactly how much electricity you need. This will help you:

  • Figure out which items could be tripping your circuit breaker or fuse
  • Gauge what generator to buy (if needed)
  • Determine how many solar panels (as applicable)
  • Find out how much batteries you need, especially if you plan to by boondocking for a while

If ever you do just want a guestimate on how much power you need for your RV, below are examples of the approximate wattage of certain RV appliances.

  • RV 30 AMP service = 3,600 watts
  • RV 50 AMP service = 12,000 watts
 ApplianceStart-up WattageRunning Wattage
BasicsRV Rooftop Air Conditioner (13,500 BTU)2800-3000W1500-2000W
RV Rooftop Air Conditioner (15,000 BTU)3300-3500W1300-1800W
Furnace Fan Motor (1/3HP)1200W
Electric Water Heater (6 gallon)1200W
Power Converter (780W)780W
Water pressure pump50W
One (1) LED Interior Lightbulb8.5W
One (1) Incandescent Lightbulb60W
KitchenRV Refrigerator (small)600W180W
Slow Cooker1000W
Microwave1000W
Coffee Maker600W
Dishwasher800W
Electric Kettle (1100W)1200W
Blender1200W
Induction Cooktop1800W
ToiletWashing Machine480W
Bathroom Vent Fan12-35W
Other Electronics/AppliancesSmall Flat TV120-200W
Satellite Receiver250W
Laptop50W
Mobile phone (charging)3.68W
Radio50-200W
Hair Dryer (1600W)1900W1800W
Printer50-80W
Portable Heater750-1500W
Portable Fan120W40W

These are averages, and the list could go on, but I really would recommend doing the work, so that you get to know your RV’s electrical load properly. This will also allow you some leeway if you want to upgrade your electrical system, your RV interior light bulbs or appliances.

What are The Different RV Batteries Available?


Deep cycle batteries are used more often for motorhomes/RVs, solar power systems, boats, etc. but they’re often marketed with terms that are often interchanged. So, when it comes to the world of deep cycle batteries, the available types are:

  • Flooded
  • Gel
  • AGM (Absorbed Glass Mat)
  • Lithium-Ion

I have a separate article explaining this in detail here, since each of these deep cycle batteries have their pros and their cons.

What Is A Motorhome Inverter?


An inverter converts the direct current from your 12v batter into a 120v alternating current. When you’re boondocking, your batteries will automatically power all items that run on DC power. Adding an inverter will allow you to use your electrical outlets and all other 120v appliances (provided you’ll have enough power stored in your batteries).Small inverters, like a 3000 unit, can even handle the easy start of small factory AC units. You can read more about it here.

Power Inverter

How Do I Set Up A Solar Power System For Your RV?

Especially if you’re boondocking, having a RV solar power system is a convenient, clean and eco-friendly way to get the power needed to charge your batteries off-grid. Provided it’s sunny, you have a modest sized battery bank of 200-300AH, a small to medium sized power inverter, and a modest sized solar panel array of 400-800W.

Setting up a solar power system for your RV will highly depend on your short and long-term goal(s), and your budget, since the upfront costs of setting one up can be quite expensive.

Adding Solar Panels to RV


Whether you set it up by yourself, or get assistance from your RV Technician (especially if you’re not too familiar with your RV’s electrical system), you’ll need to determine (1) your budget, (2) how much power you need and (3) how big your battery bank should be (including the weight limit and amount of storage space you’re allotting for the batteries).Once you have the answers set, then finding the best suppliers for your solar panels, cables, batteries, etc. will be the next step, since the limiting factor here will be your budget (and maybe time, if ever you’re in a rush to set it up). If you’re more comfortable with working with electricals, it is possible to do this on your own, but if not, I would recommend that you consult or have your RV Technician help you set this up.


Solar Panels for RV

Assuming you’ll be parking in areas that get a lot of sun, the flow of electricity would follow:

Solar panels >charge controller* >battery bank > inverter > AC system (*prevents overcharging)

Maintenance for a solar power system is low, since you’ll just need to clean the solar panels 3-4x a year (depends on how dusty/dirty they get), and might as well just double check the wiring and your battery bank (since there are some batteries that need more maintenance than others).

Rv power Wiring

What Size Generator Do I Need For My RV?


Most small to medium sized RV’s use a 30-amp power, which is 3600 watts.

While large RV’s use 50-amp power or 12,000 watts. A camper that has a 30-amp requirement would require a 3600-watt generator and a 50-amp RV would require multiple generators to produce 12,000 watts of power. The size of generator one needs is primarily determined by the power consumption that is expected. While a 2000 watt generator could work to run minimal appliances, it does not provide the full use of all appliances. If you are looking to buy a generator, you can check out this article I wrote on the information one needs to consider
when looking for a portable generator.

Portable Generator

Conclusion


We’ve covered some general safety tips, the overview of your RV Electrical Systems, and some of the frequently asked questions when it comes to this topic. Electricity is no joke, and can cause harm if not managed properly, so understanding it brings nothing but a good working knowledge of how to maintain and operate your RV properly, and keep you and your loved safe.