ac breaker box

There are hundreds of sites on the net that can show you how to do this: Bob Villa

And probably a lot of youtube videos, you just need to go and look. If you want a book there are plenty of those too for basic wiring.

Actually if I was new at this I'd want one of the books since it will help you wire the trailer up to code.

Just A/C? Go to Home depot etc. and get a sub-panel. NEC allows a 30 amp Main to be followed with up to 5 branch circuits.

https://www.homedepot.com/p/GE-PowerMark-Gold-125-Amp-4-Space-8-Circuit-Indoor-Main-Lug-Circuit-Breaker-Panel-TPL412CP/202046209

Bestconverter.com has some RV-specific electrical panels (and lots of other RV electrical things) which may be of interest, too.

The overall wiring, as time2roll alludes to, is much the same as for a residential subpanel. This means the ground and neutral busses in the RV panel need to be isolated from each other, and the ground of course bonded to the chassis of the vehicle.

A 30A RV connection is a single 120V leg, so ideally you'd want a 120V panel rather than a 120/240V panel. Most residential panels and subpanels are 120/240V panels; if you did use one, you'd have to skip every other breaker slot or do some unusual act to power both legs in the panel.

The only special thing about RV's in the AC side of life is that it is a SUB panel.. This means the neutral and ground bus bars are NOT connected.

Beyone that it wires up just like a house

THe cord or shore line goes to one or two MAIN breakers (1 for 30 amp 2 for 50) and branches to the loads.

I suggest you not forego the DC. Lighting is more easily wired with DC than AC. Some specific RV appliances require DC to operate: water heater, refrigerator. The best option is get an RV converter that has built in AC circuit breaker positions,

Yeah I see a great deal of information about running wires and actual connections but I was looking for help with choosing a panel. There seems to be many versions out there. You guys are helping me! I understand the panel is going to be a SUB panel as the main panel is the outlet in which I plug the shore line into at the campsite. Last night, I inspected my 1970 travel trailer that I referenced in my original post. I see that they used a 120v box and not a 120/240. If this is a sub panel then why do they have the 30amp fuse prior to the tandem 20 amps. Remember I have never dealt with this before but I am brave enough to pretend I know what I am doing? Side question: if I do use a 120/240 - can you elaborate on this a little more. I guess I don't quite understand how a panel works. I am going to go do a little research on that as soon as I post this question.


Ok so I educated myself a little more. Do I have this correct? The shore power cord has three wires: neutral, ground, hot. Home applications would have 4 coming from the main power source: neutral, ground, and 2 hots. A 120v panel would only have one hot bus bar and a 120/240 would have two. If I use a 120/240, I simply would not hook up the second hot bus bar. Are circuit breakers 120 specific as well?

You basically have it down as to 120V vs. 120/240V for residential wiring.

A 240V circuit (in North American single-phase wiring) is made from two 120V circuits that are 180 degrees out of phase with each other. There is a 120V potential between either of them and neutral, and 240V between the two hots.

A 240V breaker, then, basically consists of two individual 120V breakers physically tied together so they trip at the same time when either one overloads. There are circumstances where such breakers are used for two 120V circuits rather than one 240V circuit (usually where the two circuits are sharing a neutral), and many common 240V devices are actually 120/240V devices, rather than pure 240V devices, and so may not load the two legs equally.

A 120/240V panel does have two hot busses, and you'd only use one. The main breaker would presumably still be a dual breaker, but you'd only connect one side of it and leave the other one dead. (You don't want to connect the hot to both sides of the main breaker as that would permit twice the current in the worst case...and, depending on the specification of the panel, could also overload the neutral bus that normally only needs to carry the difference in current between the two legs, rather than the sum.) On some panels, those with power take-off lugs connected to the main hot buses, you could presumably also bridge them between the lugs, still using only use half the main breaker, to get more slots available for load circuits. I don't actually know if this would be up to code, but I don't see how it would be inherently dangerous.

You need a master breaker or fuse for a couple of reasons: first, to prevent an overload in the system as a whole. In your trailer, for instance, without the master fuse you could in theory have 40A flowing through the system designed for 30A with just the branch circuit fuses. Second, and just as important, it also serves as a master disconnect for the system so you can remove power in case of an emergency or for doing repairs etc. I guess a third reason is simply that the electric code (generally) requires it, for better or worse, with a few exceptions for quite small systems.

DrewE - Thanks for the info. Your input and the others on here have helped me work through this. I have a pretty good feel for my basic project. 2 quick questions: You indicate the need for a master breaker - wouldn't the pole breaker at the camp site act as the main breaker? and the second question: Running a ground from the breaker panel I am going to install should be connected to the vehicles chassis, any tips on that or testing procedures to ensure it is a strong ground?


I guess grounding is straight forward as well. Run copper wire thru floor and terminate on metal (grind to expose bare metal) of the vehicles frame. Sound about right?

A 30-amp (the pedestal) breaker is only valid for a service connection (umbilical cable) that is rated for 30-amp service. Sorry but this is electrical code regulation.

If you find a standard 15-ampere duplex receptacle on the post with a 15-amp breaker then a harness appropriate for 15-amperes would be legal and intelligent.

A ganged breaker box can have the 240 vac inlet bridged if you desire to split the box's loads.