RV Electrical Systems: Understanding How They Work
(Camp Addict does NOT accept payment from any company to review or endorse their products.)
First of all, please have a ton of respect for electricity. It CAN kill you. Yeah.
Do keep this in mind.
We will assume you have an RV.
Your RV has an electrical system.
Actually did you know that it has up to two or three types of different electrical systems?
Boy howdy, it sure can!
Don't worry, it may seem daunting now, but it will get easier once you are familiar with your rig.
This page is here to teach you all about your RV and its power systems.
You will become familiar with the 2-3 types of electrical systems in your RV and what powers them.
You will learn about 30-amp and 50-amp RV electrical cords and adapters that you may need, and MUCH more.
When it comes to your RV and electricity, there really is a staggering amount of information to know.
We are here to make it as easy for you to understand as possible.
Let's get down to it!
Need a new RV power cord? Parked too far from the power pedestal and need an extension cord? Looking for the right plug adapter? Click the button below to read our reviews.
Understanding Your RV Electrical System
Some things in your RV won't work unless you are connected to an external power source providing 120 volts of electricity.
Unless, of course, your rig has an inverter or is being powered by a generator.
What kind of things won't work unless using a generator or shore power?
Typically, your household outlets, your air conditioner, your TV (unless it's a 12-volt TV), and your microwave.
Usually, these appliances don't work off your batteries. Instead, these typically run off 120-volt power.
We are only concerned with the RVs power systems, not the RV ENGINE's power system (the automotive system) which you have only if you have a motor home.
Still, let's help you understand the difference between your two RV systems and the automotive system.
Motor Homes = 3 electrical systems
Trailers = 2 electrical systems
No matter what you have, when you plug into a shore power source, you are using the 120-volt system.
If your converter/charger is working properly, your RV batteries should also be getting charged.
Any 12-volt system will still be powered by your batteries.
Things like your lights, which could run off of your 12-volt system OR your 120-volt system will be powered by the 120-volt system.
Are you confused yet?
We understand.
Let's dig a little deeper.
12-Volts? 120-Volts? Automotive System?
RRRRRR! What does it all mean?!?!?
We know you're probably not an electrician, so we are going to make this as simple as possible.
This should help you to understand the ins and outs of electricity and your RV.
It's not a complete course on electrical systems- we are just going to give you a basic understanding of how your RV works.
Here's a simpler explanation of some of the terminology we are using:
120-Volts: The power you get from an external power source. (I.E. NOT using your battery power.)
12-Volts: This is the power you get from your motor home or trailer battery or batteries. In my (Camp Addict co-founder Kelly's) travel trailer, I only boondock. This means I rarely have external, 120-volt power.
Therefore, I cannot run the things that require 120-volts such as my AC, my 120-volt TV, and the household outlets in my travel trailer.
Those items all require 120-volt (shore power or generator power) to work.
I do have a lightweight portable generator that provides 120-volt power, the same as shore power.
I use it to power up my batteries when it has been too cloudy for the sun to let my portable solar panels for RV use do the job.
12-volt AUTOMOTIVE system: (Motor Homes only) (Battery power) Pretend your motor home is simply an engine with no additional electrical parts.
Just like a regular car.
Your car, like your motor home, has a battery.
That battery and its components are a 12-volt system.
It starts your engine, turns lights on, powers your radio, etc.
That's the 12-volt 'automotive' system in your RV, and that's about all that it powers.
You have your RV engine battery, and you have your separate motor home 'house' batteries.
Your motor home 'house' batteries are part of your 12-volt RV system (below).
12-volt RV system: (Motor Homes and Trailers) (Battery power) This is comprised of the battery (or batteries) that power things inside the living space of your RV, or everything that is not your engine.
It powers things such as the 12-volt 'cigarette lighter' outlets and USB power ports in your rig, interior lights, RV fresh water pump, likely your sound system, 12-volt TVs, and more.
It depends on what bells and whistles your RV does or doesn't have.
These batteries don't run anything related to the engine of a motorhome.
They only run some of the systems that make an RV an RV (the 12-volt systems)!
120-volt RV system: (Motorhomes and Trailers) (External/Shore power) The 120-volt electrical system in all classes of motorhomes or camping trailers are powered when you are hooked up to a shore power source.
The 120-volt RV system powers all the other 'RV related' electrical stuff... your power outlets, 120-volt TV's, your microwave, air conditioner, etc. (non-12 volt systems)
Everything can be powered by the 120-volt system in most RVs (12-volt systems are powered by a 120-volt source via your rig's charger/converter).
But not all appliances/systems can be powered by your 12-volt system (battery power) unless you have an inverter.
You would need to be running a generator, or be connected to shore power for that.
You will have to learn the ins and outs of your particular rig- what systems are powered by what voltages.
Don't worry. It DOES get easy!
RV Plug End Types
All RV power and extension cords use plug ends that are compliant with the NEMA standards.
NEMA stands for National Electrical Manufacturers Association.
It's the organization that sets the standards for electrical connectors used throughout the US, Canada, and other countries.
This means that RV power cords are compatible with power pedestals, so there is never a case of, um, this 30-amp plug isn't fitting into that 30-amp receptacle.
They just work!
Below are the NEMA connectors that you will see in 30-amp and 50-amp RVs.
30-Amp RV Plugs
A 30-amp RV plug is a three-terminal design (hot, neutral and ground).
The male (plug) end has 2 straight blades (hot & neutral) and 1 round prong (ground).
The hot and neutral terminals are at 45º from vertical, and 90º from each other.
A 30-amp extension cord has a male end with a TT-30P plug and a female end with a TT-30R receptacle.
Are your eyes glazing over yet?
No? Really???
Wow, OK, let's continue...
TT-30P Plug (top) And TT-30R Receptacle (bottom) Of A 30-Amp RV Extension Cord
A 30-amp RV power cord has a male end with a TT-30P plug and a female end with an L5-30R marine-style twist-lock receptacle connector.
The twist-lock connector is either available with a straight connector or a 90º connector (that reduces strain).
L5-30R Twist-Lock Receptacle (left) And TT-30P Plug (right) Of A 30-Amp RV Power Cord
Notice how both the 30 and 50-amp plug types have either a 'P' or an 'R' at the end?
This indicates whether the end is a plug (male) or receptacle (female) end.
- P = plug.
- R = Receptacle.
See how simple this is?
We'll let you figure out on your own why the plug end is considered 'male' and the receptacle end is considered 'female'.
Heh.
50-Amp RV Plugs
A 50-amp RV plug is a four-terminal design (hot, hot, neutral and ground).
The male (plug) end has 3 straight blades (hot, hot & neutral) and 1 round prong (ground).
The female (receptacle) end has 4 receptacles that match up with the male end's prongs.
A 50-amp extension cord has a male end with a 14-50P plug and a female end with a 14-50R receptacle.
14-50R (Female) Receptacle Of A 50-Amp RV Extension Cord
14-50P (Male) Plug Of A 50-Amp RV Extension Cord
A 50-amp RV power cord has a male end with a 14-50P plug and a female end with an SS2-50R marine-style twist-lock receptacle connector.
The twist-lock connector is either available with a straight connector or a 90º connector (that reduces strain).
Female (SS2-50R) Receptacle Of A 50-Amp RV Cord
14-50P (Male) Plug Of A 50-Amp RV Extension Cord
Amperage Of Your RV
Your RV is wired for a certain amperage.
You will either have a 30-amp rig or a 50-amp RV and cord.
How do you know which yours is?
If you are unsure, it's super easy to find out!
Simply look at the plug on your RVs power cord, located somewhere inside an exterior door (if you have a fixed cord).
Or, look on the outside of your RV (if you have a detachable cord).
A 50-amp rig has 4 prongs.
A 30-amp rig has 3 prongs.
Simple, right?
A 30-amp RV plug (3 prongs) will look like the picture below left.
A 50-amp plug (4 prongs) will look like the one below right.
30-Amp Plug - 3 Prongs
50 -Amp Plug - 4 Prong
At any given campground, there are USUALLY separate 120-volt outlets on a single power pedestal.
There's one for the 30-amp power cord and one for the 50-amp power cord.
However, sometimes you go to a park that only offers one type of plug, usually a 30-amp.
This is when an adapter becomes a necessity.
We're not going to talk about the specifics of RV power and the intricate details of electricity and power usage.
Learning more about power can be very detailed and complicated.
There are other more knowledgeable resources for figuring out how much amperage certain appliances take and what one can or cannot use at the same time.
This page is simply to learn about what cords and/or adapters you need and why, with a general overview of RV systems and electricity.
Connecting To A Power Outlet That Doesn't Match Your RV's Plug
What's an RVer to do in this situation?
The solution is easy.
You must have a 'dog-bone' or 'puck' style adapter to match your RV plug to the 120-volt outlet that you have access to.
Be aware, if you have a 50-amp rig, and you connect to a 30-amp plug, you won't be able to use as much amperage in your rig then if you were connected to a 50-amp outlet.
The same is true if you have a 30-amp rig and plug into a 15-amp (household style) outlet.
You can only use as much amperage as the outlet you are plugged into can provide
(yes, this should be common sense, but we figured we'd clarify).
However, say you have a 30-amp extension cord from your rig plugged into a 50-amp outlet
Yes, you will still have use of your full 30 amps.
It's simple math (or something like that) - there is no way you can squeeze 50 amps worth of power out of a 30-amp receptacle, but you certainly can get 30 amps of 'juice' out of a 50-amp outlet.
Don't worry, plugging your 30-amp (via a dog bone adapter) RV into a 50-amp outlet won't fry your 30-amp electrical system.
Because your 30-amp plug only has 1 'live' prong, it only accesses 120-volts.
No worries, 240-volts will NOT be going into your rig.
It doesn't work that way.
(Do NOT ever plug your RV into a household dryer plug, which looks exactly like a 30-amp outlet. Your rig will get fried...)
Do Not Plug Into That Dryer Outlet!!!
And Make Damn Sure Your Electrician KNOWS RV Systems!
NOT a dryer outlet! It's safe to plug in at this power pedestal.
The "modern voltage protection devices" that Mike Sokol mentions that could save your RV from damage due to incorrect voltage are Electrical Management Systems (RV EMS).
We discuss why you need an EMS for your RV, as well as tell you the best ones to purchase, in the RV Surge Protector guide.
Like anything else, both have their pros and cons. Let's look at the differences:
Dog Bone Adapters
The dog bone style is bigger so it takes up a little more room.
Space becomes a huge commodity in an RV.
Having a few dog bones can take up more space than the puck styles will.
However, they are more hardy and reliable than the puck style.
This makes them highly recommended over the pucks.
If you are always in a campground, you will want to have one for every scenario, so likely you should have at least 2 of them (appropriate connections for your rig's amperage rating).
Hockey Puck Adapters
The hockey puck style is not as reliable or as hardy as the dog bone styles are.
They tend to get hot while using them, so it's best to get the dog bone if you need to use one for an extended period.
The pucks are smaller though (above), so if you don't need to use them often, or for very long, you may be able to go with the pucks. You could also just have them for backups.
Want to know which plug adapters we recommend? Click the button below to read our reviews.
Why You Should Buy A Quality RV Plug Adapter
RV Extension Cords
Do NOT ever, EVER use a regular household/yard extension cord to connect to your RV!
Holy moly.
This would be asking for disaster/fire/frying of your rig.
Here's a perfect example- The guy in the below video made three common mistakes.
1. He used a household extension cord that was WAY too small for his 50-amp rig.
2. He used way too long of an extension cord, which caused a ton of heat buildup.
3. He put a large load on the insufficiently sized extension cord when he ran his A/C. This caused the too small of a cord to heat up and start a fire.
The video below shows what happened because of these mistakes:
Use The Properly Sized Extension Cord Or This Will Happen
Using a smaller diameter cable and/or a too low rated amperage cable will cause more resistance for the electricity.
Also, the longer the wire, the greater the resistance.
Long cables and/or smaller cables cause a voltage drop as well as HEAT.
Both of these can cause a fire.
If you need to use an extension cord, use the shortest cord possible.
You should make sure it has the same amperage rating that your RV's shore power cord uses.
The diameter of the extension cord wire (aka, the wire gauge) should be the same as your shore power cord, or bigger.
This way there is little to no voltage drop when you are using high powered electronics such as your air conditioner or hairdryer.
Want to know which extension cords we recommend? Click the button below to read our reviews.
Difference Between an RV Power Cord and Extension Cord
An RV power cord is either:
- Hard-wired to the RV (so the cord is not removable)
- Is a removable cord that you have to attach it to your rig via a marine-style connector with a twist-lock.
The attachment typically goes like this:
You push the receptacle (female) end of the power cord onto the male 'plug' on your rig and give it a slight twist to engage the locking pin.
You then twist the circular locking ring down (much like you are screwing the lid on a jar).
This makes the power cord attach to your rig so it won't get knocked loose.
The other end of an RV power cord has traditional straight blades so that it can connect either to a power pedestal or an extension cord.
Twist-Lock RV Power Cord
An RV extension cord has straight blades, NO curved blades, on both the male and female ends like in the photo below.
So to connect an RV extension cord you simply plug it to the straight blade end of your RV power cord (just like you would with an extension cord you use at home).
There is no twisting or other locking mechanism.
The tension of the straight blades on the male plug end going into the receptacle end of the adjoining cord is all that holds things together.
You use an extension cord together with your RV's power cord.
An extension cord alone cannot provide 120-volt power to your rig.
RV Extension Cord Male And Female Ends
An RV Extension Cord Plugged Into An RV power Cord
How To Plug Your RV Into Shore Power
So you get to your destination campground, you pull into your spot, get level and now it's time to plug in your 30 or 50-amp RV cord.
HOLD UP!
Don't be tempted to just plug in without testing the outlet first, no matter whether you have a 50-amp plug or a 30-amp plug.
There are plenty of campgrounds that don't have their wiring correct on any given pedestal.
You should first test the outlet using a polarity tester or a surge protector.
(Only use a surge protector IF that surge protector tells you if the outlet is wired properly or not.)
This is good insurance for keeping your electrical safe and sound.
An ill-wired outlet, or even too little power coming through the outlet, can lead to an RV electrical disaster.
Always, always check the power at the pedestal first!
Inspecting An RV Power Or Extension Cord
If you have a surge protector that plugs in at that pedestal, plug it in first, WITHOUT your shore power cord attached.
It doesn't matter whether it's a 50-amp RV cord or a 30-amp RV cord.
Once it reads ok, then you can plug in your shore power cord.
If you have a surge protector mounted inside your rig, make sure you have the kind that will 'test' the pedestal before allowing power to enter your rig.
Most interior-mounted surge protectors will do this, but make sure before you go plugging it into a pedestal.
If there is something wrong with the pedestal, the built-in surge protector will not allow power to get in and you should be alerted.
Should this happen, you should also alert the owner of the pedestal.
(Be aware, they may or may not listen to you. If they disagree, you better ask for a new spot or leave. It's not worth the risk of blowing up your entire rig.)
Checking Power Source Polarity, etc.
Do you just willy-nilly plug your RV shore power cord into a power outlet (pedestal) and hope that all will be right with it?
The majority of the time this is an OK way to go on with life, but when things go sideways with power, they go sideways in a big way!
You need to make sure that the power source you are using is wired correctly.
That is unless you like to start fires and fry expensive electrical systems on your RV.
There are two ways to check if the power source is wired properly.
If you are using a 30-amp power source, you can buy the Camco Power Defender circuit analyzer described below (not available in a 50-amp version).
Or you can be really smart and use an RV surge protector.
It will not only tell you if the outlet is wired correctly, but it will protect you from a lot of other potential electrical issues.
You are playing with fire (literally) if you don't check your power source before you plug your rig in.
It isn't unheard of for a power pedestal (or other power source outlet) to be wired incorrectly.
Such an event can cause major damage to your RV's electrical system.
CHECK before you plug in!
We recommend that you use a good RV surge protector (or more specifically, an electrical management system).
It will tell you if the outlet is safe to plug into, and it can protect you from voltage spikes, low and high voltage conditions, and more.
It's well worth the money to have this kind of electrical protection for your rig!
If you want to only have the bare minimum to allow you to check the outlet condition, you can use the Camco Power Defender circuit analyzer.
This is available for 30-amp receptacles only (you can use an RV surge protector if you have a 50-amp plug) and checks the condition of the ground, neutral and hot-wiring, as well as checks for correct polarity.
It also offers 1050 Joules of voltage surge protection.
Camco Power Defender Circuit Analyzer (30-amp)
Hot Skin Detection
There is an electrical danger caused by an incorrectly grounded RV that is known as 'hot skin' condition.
Hot skin is when your RV is electrified (any metal portion of the rig) due to a faulty electrical ground.
It can range from either a mild electrical tingling sensation to a massive shock that could potentially put you into cardiac arrest.
Hot skin is caused by an incorrectly wired power pedestal (shore power source), damaged RV power/extension cord, and/or wiring damage internal to the RV itself.
You only have to worry about this condition if you are plugged into a 120-volt power source (shore power or generator).
So if you are out boondocking and only have the 12-volt system humming along, you won't experience a hot skin condition.
You can protect your rig, and yourself, from a hot skin condition caused by an improperly wired power pedestal by using an RV surge protector.
This device will prevent power from reaching your RV (and causing hot skin) if there is a problem with the power source (improperly wired, etc).
To detect (or feel) a hot skin condition, you have to be standing on the ground and touching a metal part of the RV with the detection tool.
When you are standing on the ground, your body is forming the ground circuit for the RV that has the hot skin condition.
This is explained in the below video.
Explanation Of RV Hot Skin Condition And How To Detect
As Mike states in the above video, anyone who plugs their RV into shore power should have a voltage detection too.
Test your rig each time you plug-in (and before you touch your RV).
The Fluke VoltAlert tool that Mike recommends has an issue - it has a voltage sensitivity range of 90-1000 Volts AC.
The bottom end of the voltage range is above the 40 volts that Mike demonstrates in the video.
While it appears that the Fluke tool detects at this lower voltage (and Mike has stated on his blog that it will detect at 40 volts), we aren't comfortable recommending the Fluke device.
Instead, Klein Tools makes an equivalent tool that has a voltage range of 12 to 1000 volts AC. We like that!
You can purchase the Klein NCVT-3 via the below link.
It's quite affordable insurance against being electrocuted.
How To Plug Your RV Into A Portable Generator
When I (Kelly) first got my Yamaha 2000isportable generator, I was totally scared to use it.
I didn't know how to.
Then someone showed me how and it was embarrassingly easy!
Because I understand how intimidating it can be, I am going to explain to you how to do it as well.
First, know that most generators are not made specifically for RVs (unless they are specifically RV ready such as the Champion 75531i).
Therefore, you may find that there is no outlet on the generator that fits your RV power cord.
Now what?
Once again, you simply need an adapter. (The Camp Addict camping generator guide has a section on generator adapters that will walk you through what you need.)
Connecting Your Portable Generator To Your RV
1. If your RV is equipped with an inverter, turn it off.
2. Get the generator out, make sure it has sufficient gas and oil.
3. Turn the generator on, according to the instructions for your generator. Let it warm up for about a minute or according to the manufacturer's directions.
4. The generator's outlets are now 'live'.
5. Plug your shore power cord (with the appropriate adapter if necessary) into the generator.
6. Your rig should now have 120-volt power!
That's it! Easy peasy.
Generator Power Cords
A generator power cord isn't anything special.
You use your regular RV power cord to connect the generator to your rig.
The trick is how you plug your power cord into the generator.
Most 2000-watt generators have one (or more) 15-amp power outlets (just like what's in a house).
Some 3000 watts (and larger) generators come 'RV-ready' which means your 30-amp power cord can plug directly into it.
Most have a special receptacle that requires a special plug adapter.
So there is no special 30-amp generator cord or 50-amp generator cord.
Unless you are the lucky owner of an RV-ready generator (has a standard TT-30R 30-amp receptacle), you need to purchase the appropriate power cord adapter for use with your existing RV power cord.
See the portable generator page section on generator adapters to learn more.
RV Power Cord Connected Via Dog Bone Adapter
Summary
There you have it.
It's complex, isn't it?
After you get to know your RV a little better you will more easily understand your RV power systems and how to use them.
Please be careful when using any type of power with your rig. 120-volts is nothing to mess with for sure.
Even your 12-volt system can give you a good zap if used incorrectly.
We hope you got some useful information out of this page regarding how to get power to your rig and regarding RV electricity in general.
Play it safe.
Use your head.
And if you have any questions, please read the comments below first.
Thank you for trusting Camp Addict!
Authors: Kelly Beasley & Marshall Wendler
Kelly Beasley
He-llllo. I'm the co-founder of Camp Addict, which my biz partner and I launched in 2017. I frigging love the RVing lifestyle but in December of 2020, I converted to part-time RV life. Heck, I lived in my travel trailer for over 5.5 years, STRICTLY boondocking for pretty much all of it. Boondocking is a GREAT way to live, but it's not easy. Anyway, I'm passionate about animals, can't stand campgrounds, I hardly ever cook, and I love a good dance party. Currently, I can be found plotting and scheming whether or not to start collecting farm animals (or plotting my next RV trip!) at my beautiful new 'ranch' named 'Hotel Kellyfornia', in Southern Arizona.
Marshall Wendler
Camp Addict co-founder Marshall Wendler brings his technical expertise to help explain RV products in an easy to understand fashion. Full-time RVing from April 2014 - December 2020 (now RVing about 50% of the time), Marshall loves sharing his knowledge of the RV lifestyle. Marshall spends the majority of his RVing life boondocking. He is the part of Camp Addict that knows 'all the things'. He's good at sharing his technical knowledge so you can benefit.
Thanks in advance. I have a 2008 arctic fox 5th wheel. Inside the power cord door is my power cord for shore power but also is a receptacle that is a male version of my power cord. What is it for?
Hi Jeff,
Without seeing a picture of what you are talking about, I really don’t have a guess as to what it could be.
Have you contacted Northwood Manufacturing (the manufacturer of your Arctic Fox)? They would be able to tell you what that is.
I have a 50 amp plug that is a splitter into two 30 amp/120v connections. Can I plug one of those into the 30 amp receptacle and the other into the 15amp/110 outlet with a 15amp adapter at a pedestal? This giving me two hot legs into the 50 amp plug but at different amperage. Will that power one A/C unit and microwave on the 30 amp, and the other A/C unit on the 2nd leg/hot from the 15 amp?
Hey David,
Thanks for the comment!
I assume you have a 30-amp/30-amp (so dual 30-amp male plugs) into a single 50-amp female adapter like this. Note that on this page they say the following:
“It is recommended that you use this adapter to plug into separate 30A circuits. It is your responsibility to verify if this product will work with the wiring you are connecting to. It will not work on GFCI protected outlets. It is also your responsibility to test and monitor power usage to your RV/equipment.”
It sounds like they don’t recommend doing what you are inquiring about.
Camco makes an adapter that has a 15-amp and a 30-amp male plug and a 50-amp female plug, which sounds like exactly what you are looking for. View that item here on the Camco website. They claim you will then have up to 45 amps (30-amp plus 15-amps) to use.
As far as being able to power certain systems off the 30-amp and other systems off the 15-amp, that isn’t how these types of adapters work. The adapter “feeds” the single shore power inlet of your RV. In other words, it provides power to one location on your RV, just as if you had plugged into a 50-amp receptacle.
So the RV will use the incoming power as needed. So if you are getting the theoretical maximum of 45 amps using the Camco plug AND your rig uses less than 45 amps for the two air conditioners and the microwave, then you should be fine. However, the AC units and the microwave are the biggest consumers of amperage/power so I’m not sure you could run all three at one time even in a perfect shore power situation. Something you will have to try. If your RV is wired correctly, then the circuit breakers will keep you from drawing too many amps from shore power (by ‘popping’ a breaker). Or, more realistically, the circuit breaker(s) at the shore power pedestal will ‘pop’ because you are asking for more amps then the 30-amp and 15-amp circuits can provide.
I’d be really shocked if you could run both AC units and the microwave at the same time off the splitter.
Welcome to the world of power management when you are trying to run multiple high power usage appliances at one time. One of the ‘joys’ of the RVing lifestyle (learning how to manage power).
What I don’t see you calrifying, probably because you are trying to uncomplicate a complicated topic, is that a 50A/240V service is used by the RV as 2 separate 50A/120V ‘mains’ that supply separate, subordinate branch circuits inside the RV panel. Each of these 50A/120V ‘main lines’ is distributed onto multiple 15A and 20A branch circuits inside the breaker panel (every branch is protected by a breaker). Each A/C will be on its own breaker as will the microwave, and interior convenience outlet(s).
The topic of using a ‘Y’ cable to connect to UNEQUAL SOURCES at a power pedestal through a 50A/240V supply cable makes the RV wiring relevant. When using the ‘Y’ connector to adapt, you connect one ‘main line’ to a 30A source and the other ‘main line’ to a 20A source means that these sources will feed the two different sets of branch circuits inside the RV. They don’t ‘combine’ the 20A/120V and 30A/120V sources into a single 50A/120V supply (nor can they). Inside the RV you will receive 20A capacity on one main line and 30A capacity on the other main line (and you won’t know which is which). Assuming an RV has 2-A/C’s and a microwave, at least 2 of these devices will be on one of the mains. If the two are on the 30A line, you will be able to operate both simultaneously. If they are on the 20A line, as soon as you start the second device, the pedestal 20A breaker will trip.
TO SOLVE THIS PROBLEM; Do not use the ‘Y’ connector cable with a separate 20A and 30A plug. It prevents you from doing what I’m about to tell you; Use the one with dual 30A plugs and a 30A to 20A dogbone. This will allow you to swap the 30A dogbone between the two 30A plugs to ‘swap’ the 30A source with the 20A sources to place the larger source on the main line with two high-power devices. If you do this, you should be able to run 3 major appliances on the (not) combined source, simultaneously. If you do it ‘wrong’, only 2 will run at the same time.
Thanks for stepping in with this reply, Steve. Not going to lie – my head about exploded when I read your response. Because electricity is one of those topics that make my head start spinning when getting into the weeds with it.
I learned a lot from this reply, so thank you!
Nice job both
Thank you, Bob!
I think you simplified it a bit too much by just saying 120 volt and 12 volt. It should be explained that the 120 volt is AC or alternating current and therefore the dangerous type that can kill you. 12 volt is DC or direct current and while a shock can kick you on your butt it won’t kill you. So you must be more careful with AC than DC.
Hi Bob,
True. I like to think we tried to scare everyone from BOTH types of electricity here by stating that it can kill you in the first sentence. I even act like DC current can kill me when I have to deal with it. I know it will probably shock me at most… still, I don’t even want a shock… not fun!
But yes, AC current can kill you, DC current will be extremely unpleasant but not going to kill anyone.
Thanks for the tip! I want everyone to be EXTRA CAREFUL with both!
Cheers!
NOT TRUE. AC at 120V is just as problematic as DC at 120V because your body’s resistance is what prevents the intensity of shock (current). The ONLY reason 12V DC is not problematic (it effectively cannot shock you) is the voltage is low. There ONLY factor between the intensity of shocks is the voltage, not the type of electricity.
Hi. I’m a newbie to full-time rv living so I dont know very much about the electrical aspects. I’m curious if you know either what I did and/or how to fix it; there are 2 lights sockets in my rv living room that take the single contact bayonet bulbs 1156. Well trying to replace a burnt out bulbs, I mistakenly tried to connect a double contact bayonet bulb instead… so upon inserting it, the identical light socket (was powered on at the time) immediately turned off and neither light sockets work anymore. And not only those two light sockets but also my tank sensor control unit, to show me how full my tanks are and turn on/off my water heater and water pump and change my water heater from ac to propane, aren’t lighting up anymore, my radio isn’t recieving power anymore, and my water heater isn’t recieving power anymore. I’ve checked all the fuses in the control panel inside my rv and reset all the breakers, disconnected and reconnected my power cord, reset the breakers from the pedestal I’m connected to, and still have not managed to regain power to these items. I’m assuming the problem has something to do with my 12v system since all items are in some way (I believe) connected through my batteries or 12v system. But I’m not sure what I did or how to fix the problem. Any help would be greatly appreciated. Thanks for your time and consideration.
Kind regards,
Jenna
Hi Jenna,
Sorry for your electrical problems! Speaking from first hand experience, they are no fun at all. Unless you love chasing down electrical gremlins. Personally, I find these to often be exercises in frustration. But electrical isn’t my strong suit.
It definitely sounds like some sort of circuit protection device (fuse, etc) was ‘blown’ during the attempt to replace the bulb. Where this might be is the great question, especially because you checked all the obvious candidates.
It sounds like you are on the right track thinking that something that controls/supplies power to many of your 12-volt systems is the culprit. Normally the battery ‘feeds’ the electrical distribution panel when you aren’t plugged into shore power, and the converter ‘feeds’ the distribution panel (and charges the house batteries) when you are plugged into shore power.
I’m not certain (remember, electrical isn’t my strong suit) how this is done in your particular situation. It may vary from how it is done on my trailer, as your setup may use a different distribution panels, wiring setups, etc.
If you have a wiring diagram, you may be able to trace how this is done (assuming your rig is actually wired per the diagram – fun times!).
Basically one needs to get down and dirty with a wiring diagram, a multimeter (to check power at certain points), and a decent knowledge how electricity works and troubleshoot the system. This may be something you are comfortable doing, or you may need to find someone who enjoys playing with electrical systems.
Unfortunately I don’t know what the issue is and can’t be of anymore help since I don’t have your rig in front of me. Even then, it may be beyond my technical capabilities (ugh, electrons and such make my head want to explode sometimes).
Best of luck figuring out what the issue is. Hopefully it’s just a ‘hidden’ fuse somewhere that is easy to replace!
Thank you so much. I’ll let you know if/when I located the culprit.
I have tent camped for years with my two boys. Now that they are grown, my wife (someone who was not into tents) and I just purchased our first RV.
As someone new to all the goodies contained in, or available for, today’s class C motorhomes, I have really enjoyed reading Camp Addict and appreciate Camp Addict’s approach.
Recent articles that were great for a newbie included surge protection, RV wiring system, 12v vs. 120v TV’s, and flat towing tow bars and brake systems. Looking forward to any Camp Addict articles on TV antennas vs. cable connections, vs. satellite dish, vs a device that will stream using your phone as a hotspot.
Thanks again for the education!
Wow, Rick! This sounds almost like a sponsored reply, lol!
We are honored and we are more than happy to help! Question for you- do you use a satellite dish with your RV? Personally, I am surprised anyone uses any dish subscription anymore with all of the other options we have for WAY less money and no lock-in. (HULU, Amazon Prime, Netflix, etc) Oh, I do suppose many need it for sports. (Neither of us are into or watch any sports)
In that case, I think options are limited, unfortunately.
Also, we don’t stay in campgrounds, so that outs the idea of using cable connections. It’s just too easy to use something like Apple TV or a ROKU connected to your RV TV to have access to a ton of online content. I have not watched cable TV in 6 years, except for the rare occasion at a friend’s house or maybe seeing a TV on at a bar or restaurant.
I have a ROKU connected to my TV in the RV. I have a Nighthawk hotspot that it connects to. There, I can watch anything from Netflix to Amazon Prime. However, I watch 95% of my shows on my phone.
I’m 99.9% sure neither of us will ever have a satellite on our RVs or use cable in a campground. It’s just too easy (and cheaper) to use our online streaming options.
Thanks for being a fan, Rick! We sure appreciate your taking the time out of your day to give us a positive comment/review! 😌
Kelly and Marshall,
Thank you both for your responses. Our RV came equipped only with the basic over-the-air digital antenna. Knowing we don’t want an expensive monthly dish subscription, your recommendations to stream digital content sounds like the best approach for us.
In regards to a digital hotspot, is there a benefit to using a Nighthawk hotspot vs using your cell phone as a hotspot?
Thanks again for your guidance, and yes, a reminder to spend more time out in nature.
Hey Rick,
You are most welcome! We love helping fellow RVers, both newbies and experienced.
There are a few benefits to using a Nighthawk (or other) hotspot versus using your phone:
1) Your phone may have a limit to how much data you can use when you tether it to something (assuming you aren’t watching on your phone itself).
2) A hotspot (Nighthawk, etc) can be used with a MIMO antenna (think cell signal booster, but cheaper and much easier to manage), which can help when you are in those areas with less than stellar cell signal.
3) A hotspot (Nighthawk, etc) can provide internet to many devices at one time. Your computer, a streaming device or two, a tablet, even your phone, etc. A phone is limited to the number of devices that can tether to it at one time (I think this is the case, but maybe it has changed recently? I’m not the expert on these things. 🙂 ).
Overall, if you are going to be using a decent amount of data on multiple devices (that don’t have a cell internet connection themselves), some sort of hotspot is really the way to go. And for some internet connected devices, it may be your only option.
Hope that helps! Sounds like you are getting your system/setup dialed in.
Hi Rick,
Thanks for the kind words! We are glad you found Camp Addict!
We don’t have any immediate plans for creating a TV service article like you mentioned as we only consume that type of media using a streaming service and our cellular hotspots. Yes, it can really use a lot of data, but we both have unlimited data plans, so that’s not an issue. For many people with limited data, this might not be an option.
Unless you are full-timing (and in that case, you will probably have unlimited data), it might be too much of a hassle to figure out a good system to watch TV. Might be better to just enjoy being out in nature. 😉
Thanks again for checking out Camp Addict!