I'm trying to install an outlet for my RV. My current one only needs 30 Amps, which is simple to do, just install a 30amp breaker and use wire big enough to handle 30 Amps. However, if I'm going to the trouble to do this, why not install 50 Amp service instead, in case I ever upgrade RVs... The trouble is that I'm not sure what the 50 Amps really is. Since it has 2 source pins and 1 return pin (plus ground), I obviously need 2 breakers. But is it 50 Amps each leg, or 25 Amps each leg? Do the 2 legs need to be out of phase, in phase, or does it matter?

What is '50 Amps'? It's 25 amps on each leg. Basically, it's two 25 amp services on one plug. Of course the 50 amp recepticle is different from the 30 amp (4 prongs instead of 3, as you know)so if you install a 50 amp RV recepticle you will need an adapter to plug in your 30 amp rv shore power.

What is '50 Amps'? Of course, got one of those adapters before my first trip, just in case. But that brings up another question. If '50 amp' service is 25 amps on each leg, doesn't that mean that if I use the '30 amp' adapter I'm really only getting 25 amps?

What is '50 Amps'? Yep. Unless you were to put a 30 amp breaker on each leg instead of 25. And have the wiring to handle it, of course. It wouldn't cause a problem with a 50 amp coach because it would (should) have it's own main breaker inside the coach to protect the coach wiring. And you would have the two 30 amp breakers to protect your wiring.

What is '50 Amps'? There are several diffeences in the 30 amp and 50 amp circuits used in the RV industry. The 30 amp circuit is 120 volts, three wire, on a single pole 30 amp breaker. The 50 amp circuit is 120/240 volts, four wire, on a 50 amp two pole breaker. The RV only has 120 volt apparatuses and so you will not find any two pole breakers in the panel. The 50 amp circuit provided supplies 240 volts (measured between the two) onto the two hot bus bars in the RV electrical panel which is 120 volt between either to the neutral bar and will allow 50 amps to flow before the breaker will trip out. Unless you are clear on these two circuit I would recommend you have a qualified electrician design and at least supervise this job.

What is '50 Amps'? Would a 'qualified electrician' necessarily know about how a RV service needs to be wired? Or should that be a 'qualified RV electrician', and how would I find one?

What is '50 Amps'? A qualified electrician should know; the codes for RV parks are in the same NEC (National Electrical Code) book. One that has had experience in the RVC parks will be more efficient in designing. A seasoned electricain will not have much trouble if you tell hime that all circuits in the RV are 120 volt.

What is '50 Amps'? Have you considered just running the proper size and type wire for a future 50 amp RV service, but utilize it for a 30 amp service? That would leave you the option for the 50 amp service later and you'd not have to pull wire again.

What is '50 Amps'? That is, of course, an option. I'd prefer to have 50 Amp, 30 Amp and 15/20 Amp outlets, all in the one box. Start with a dual pole 30 amp breaker, 3 conductor (plus ground) 10 ga wire, and a 30 amp RV box. Wire 1 leg to one source of the 50 amp socket and the 30 amp socket. Wire the other leg to the other source of the 50 amp socket and the input of the breaker which comes with the RV box. Replace the 30 amp breaker in the box with 1 20 amp breaker or 2 15 amp breakers, and power 15/20 amp sockets from that as appropriate. It would actually be 60 amp service, but as smallcamper says, the RV main breaker will prevent more than 50 amps being drawn. The main circuit breaker will protect the 50 amp and 30 amp sockets, and the built in breaker will protect the 15/20 amp sockets.

What is '50 Amps'? When I said to have an electrician design and possible supervise this project I knew that he or she would give the 30 amp and 20 amp circuits and receptacles consideration as well as just the 50 amp. Panel boxes just like in a campground only at home. The difference in price from just a 30 amp to 50 amp is not even twice the price but oh so much more convienent!

What is '50 Amps'? Price is irrelevant compared to the hassle of stringing the wire... Oddly enough, Home Depot has a 50 amp box for about $25 and the 30 amp box for about $35 (because it is bigger and has a built in circuit breaker). I don't know about that, the qualified electrician my dad used to install a 30 amp outlet for me at his place only installed a 30 amp outlet... I guess some volunteer additional possibilities and some don't. In any case, the selection of outlets has been part of the concept from when I first thought of doing it. It's just that now I am in the panel box adding a circuit for Christmas lights so it is more likely to transition from dream to reality.