RV Walk-Thru: Electrical - Learn about the electrical system on your RV

the first thing I need to explain about electricity is that in the wrong hands it can be deadly if you don't know what you're doing don't understand how it works leave it alone get some help from someone who is qualified and that really knows I was called out to look at a problem a lady was having with her trailer she'd moved her RV into the backyard of her daughter's place and had a neighbor put a 30-amp receptacle on a post for her to plug in this neighbor thought the plug was 220 volts like the type you see on a dryer as you can see they look somewhat similar and he wired it in that way when the lady connected the RV to the post the TV microwave and other appliances that were plugged in were destroyed and it blew the circuit breaker in the breaker box now not knowing what the neighbor had done I reset the breaker and as soon as I touched the trailer which was metal I was immediately lit up like a Christmas tree thank the stars it was me that touched that coach and not her it could have been deadly now if you have working knowledge of AC and DC power you might find the first few minutes of this boring and a little bit long-winded but be patient I think if you understand a little about the electrical system on your unit you'll feel more comfortable and confident also you might be able to save some money on repairs both problems can be solved or found with a test light a hairdryer and some common sense will start the demonstration explaining the difference between AC and DC power AC power or alternating current is the same stuff you have in your home it runs your TV microwave lights and so on we will continue to call this AC power DC power or direct current is the power you have in your automobile it powers the starter lights ignition and basically everything in the vehicle we will call this DC power RVs have both power systems in them and I believe it's important to understand a little bit on how the two interact in the early years RVs were intended to dry camp meaning that most appliances ran off propane and a few lights they had ran off the batteries or DC power well our V's are bigger and fancier and they have more toys in them but the concept is still based the same they still are designed to run out in the backwoods and they need DC power to run them did you know the fridge in your unit must have DC power to run even on propane their little brain box or module in them that is powered by the battery to make them work same with the furnace its DC power and of course propane same goes for the water heater if you have the DSi model you direct spark ignition the type you just flipped a switch most if not all lights are DC powered and when the battery goes dead nothing works if equipped when you total or motorhome engine is started the alternator charges the batteries but they will never get fully charged that way I'll explain that later that's why we have converters that is converters with a/c not inverters with an I people get the two confused all the time I will explain inverters later on as well converters convert AC power to DC power quite simply a converter is a battery charger when you plug in your unit the converter charges your batteries and runs the 12-volt or DC powered accessories converters are designed to be plugged in for long periods of time or short stays they have a voltage regulator in them and if working properly will not overcharge the batteries but will top them right off understand that batteries need a long steady charge to bring them back to full strength so let's say you're planning to go into the woods for the long weekend it'd be a good idea to plug your unit in for a week before going that way the batteries would be fully charged and if you use the system conservatively you could make it through the entire weekend an inverter works in Reverse it takes DC power and turns it into AC power they come in different sizes and shapes and if you have one of the bigger ones you can watch TV cook in the microwave and so on they're a great thing to have but they have to be set up properly they require a great deal of battery power and they're quite expensive if you do a lot of dry camping they're great but if you go to full hookup RV parks you don't need them they make AC power where there is none let's assume you have a travel trailer no generator no solar power if you are a dry camper batteries are the heart of the system without them the RV is dead so it's important to learn how to make them last as long as possible there's a lot of information on batteries but the only things you really need to know is amperage draw reserve capacity and how they affect you first off let's talk about DC voltage think of voltage measurement of strength the higher the number the stronger the system 12 volt 24 36 and so on on RVs we use only 12 volts it's very important to remember that if you think of amperage draw or amps as the speed that electricity goes through the wire it's like a speedometer it's a way of measuring the speed of the current going through the system the higher the number the faster the electricity is flowing through the wires one light bulb might use 1.5 amps two bulbs three amps and so on while we are talking about amps or amperage let's touch on fuses for a minute they come in different sizes and shapes fuses work like a speed zone if the system only needs up to 15 amps of electricity a 15 amp fuse is installed for whatever reasons say the wire is shorted to ground or the system is overloaded and the amperage exceeds the fuse amount it burns out you see when electricity passes through a wire it creates Heat the higher the speed or amperage the more heat is created that little wire in the fuses just like my wife it's designed only to take so much a little glows if something quits that is DC powered the first place you should go to is the fuses depending on your coach you might find the fuses all over the place you should make a point of knowing where they are and what they do if yours are the ato type like these you can probe them with a test light to see if they're good or not I like this method the best make sure you have a good ground and pearl both ends of the fuse fuses can look fine but they can be burnt out here I found a bad one blast fuses can be tested the same way just touch the tip on the metal part and check both sides and remember never use a test light on AC power it's for DC or bad power only now here's some neat devices called circuit breakers they can be installed in place of a fuse the nice thing about them is that if there is a problem and the speed limit is broken or the amps have been exceeded they blow just like a fuse but after they cool down they automatically reset themselves if the problem is a once in a while thing like a power surge everything goes back to normal but if it's something serious it will continue to blow and reset and will protect the system until it is fixed or the breaker wears itself out remember that the system that you have in your RV is a 12-volt system whatever combination of batteries you put in your RV it must always come out as 12 volts DC now what do I mean by that I'm going to explain parallel and series hookups and at the same time explain reserve capacity throughout the years I've seen people hook up batteries wrong and set fire to their counters when you jump or boost one vehicle with another you hook positive to positive and negative to negative that is a parallel hookup when we put more than one battery on our units we do the same we hook them in parallel this serves two purposes it keeps our system 12 volts but best of all we double the reserve capacity reserve capacity is how we rate or guess the time a battery will last let's say you have a 12 volt battery that has a reserve capacity of 175 minutes in theory the battery will last for 175 minutes at a 25 amp draw now if and not likely you had 16 lights lit at the same time and each leg draws 1.5 amps your battery would be dead in 175 minutes now if you hook two 12-volt batteries each with 175 reserve capacity in parallel you get 12 volts and 350 minutes reserve capacity you see the voltage stayed the same but the reserve doubled let's add another one now we have 12 volts and 525 minutes Reserve do you see what's happening here as long as the batteries are hooked in parallel the voltage stays the same but the reserve increases important to mention never mix reserve capacities and sizes of batteries that means if you have for instance a hundred and seventy five reserve and 150 reserve don't put them together they will fight each other and cause problems okay that's the 12-volt batteries now we're able to put six volt golf cart batteries in our RVs they have incredible reserve capacity but the clincher is we have to buy two of them and that's why we have to talk about series hookups remember when I said whatever combination of batteries we come up with it must always come out as 12 volts here's what I mean let's say we have two six volt batteries if you take them and hook them the way we did the 12 volt ones we would still have six volts well that won't work but if we hook the batteries in series we will get what we need here's how we do that with the batteries close to each other a jumper wire is put between one of the positive posts of one battery and the negative posts of the other notice that leaves a positive and a negative post free we've just made a 12-volt battery system with two six volt batteries and a reserve capacity of 480 minutes unlike the parallel system when you hook in series you double the voltage but the reserve stays the same if you need more reserve capacity you need to hook another set of batteries in parallel now you have both hookups involved this is called a series parallel hookup we now have a 12 volt system with a 960 minute reserve capacity and that's why a lot of people do this this system takes up a little more space cost more but you get two hundred and sixty minutes more reserve capacity or four-and-a-half hours more that can make a big difference when you dry camping now let's move on to AC power remember my story about the lady getting her power hooked up wrong AC can be deadly if in the wrong hands if you don't know what you're doing get help the AC power on your coach is the same as what you use in your home the one little difference is the GFI ground fault interrupt or GFCI ground fault circuit interrupters have them in the kitchen bathroom and other places and so do our vs the difference may be that in RVs several other receptacles can be tied into one GFI they're just a super sensitive circuit breaker they're designed to pop or blow quicker than the circuit breaker in the panel they're a great device and I'm sure they've saved many lives but if you don't know about them they can cause you some grief now I've been called out several times to find out one side of the customer's coach has no power only to find they didn't check the reset button on the main receptacle like this one it's not uncommon to find the kitchen receptacle tied into an outside plug and when it rains the GFI pops or a curling iron pop the one in the bathroom and the TV won't work I've seen as many as five GFI circuits on large motor homes you should find all of yours and find out what they run you can test to see if they're working by pushing the test button and the reset button should pop out all the receptacles related to that GFI should stop working push the reset button and everything should come back on if not get someone qualified to look at it your circuit breakers are the same as the ones in your house again I've seen people not resetting them properly don't be fooled sometimes they look ok but the only way to know for sure is to move them all the way to the off position and then to the on I just wanted to touch on the different types of AC power services that RVs use most of the units come out with a 30 amp service like this one if you're not in an RV park and need power you can adapt to what most of us call a 15 amp adapter and plug into your house do you remember me talking about Amp draw in the DC power section and that more amps create heat the same principle applies with AC power when you use the 15 amp adapter you need to limit the amount of power you use you shouldn't use your air conditioner it can draw as much as 20 amps your toaster can draw as much as 15 amps by itself and so on if you overload the system it will most likely blow the breaker in the place you are plugged into and literally melt the 15 amp adapter if you have a larger trailer or motorhome you might have a 50 amp service that looks like this they're designed to allow you to do just about anything in your coach you might be able to run both air conditioners do a load of laundry watch a movie and make popcorn all at the same time but in some RV parks they're hard to find so we have adapters that bring us down from 50 amp service to a 30 amp service and again to a 15 amp service just keep in mind that every time you adapt down you have to limit the power usage another thing to remember is to use the shortest extension cord possible there's a thing called voltage drop that would make me drag this thing on more than I already have trust me if you can use a 25 foot cord instead of a hundred-foot or do it

Channel: RV Walk-Thru

Views: 2,112,713

Rating: 4.8001885 out of 5

Keywords: rv, electrical, shore power, Recreational Vehicle (Industry)

Id: 7DpIzugALqc

Length: 14min 10sec (850 seconds)

Published: Wed Apr 09 2014

Reddit Comments

[u/gilliganphantom]

That was helpful. Thanks for sharing.

[u/[deleted]]

The wife joke was a little odd, but that was a fantastic intro. Thanks!