Originally Posted by cincinnati_kid
... Why let your electric inside the bus be the limiting factor? You never know what you might want to add and its nice to have the extra capacity. If your building a custom system (like most of us are) why not build do 50 amp?
For folks like us, the amps our bus can take is not the problem, it's WHERE we camp at. If we don't have to be long term (which means a private campground... but we have spent 3 months in a state park...in the winter) then our #1 choice is a public campground. That means 30 amps are the norm for us. We can run a fair amount of stuff on 30 amps. Right now my biggest problem is I only have an ancient circa 1977 GE fuse box with 4 circuits in it. I have 30 amps main, 15 amp ground fault in the breaker box (DO NOT TRUST THE CAMPGROUNDS GROUND FAULTS... ADD ONE TO YOUR BREAKER BOX) another regular 15 amp breaker and a 20 amp breaker. The 20 amp has the A?C on it plus we plug the electric heater into it as well during winter. Right now, it also powers our big commercial electric pourover coffee maker (have to shut the heater down when it's plugged in). I also have 2 under counter refrigerators, 1 under counter freezer, a desktop computer/monitor plus printer, a 1000Watt microwave, 26" flat screen TV, DVD player (the VCR died and we are on park cable so I don't need the DISH box). All 10 of our lights are 12vDC. I cannot run the hair dryer on the HIGH setting on anything except the 20 amp circuit or I pop the breaker. This (and the coffee maker) will be on their own circuits in the bus. We never run everything all at the same time. That is something you need to understand when you set up your circuits. There are circuits that can only run specific things.
For the Bus...
We will still operate on a 30 amp main breaker with a ground fault circuit breaker in the panel box. I would rather my breaker trip and not rely on a possibly faulty campground breaker (and yes I have run across several). Our power cord is a 60amp/220vAC that we used as our welder's extension cord. We will simply plug the power cord into the generator when we need to use the generator. That is how we set the RV up and it has worked well for us. It's simple and we don't have to worry about feeding power backwards into an unprotected system.
30 AMP main breaker
30 AMP: 4 CF refrigerator, 12 CF upright freezer
30 AMP: Air conditioner
30 AMP: Water heater (for the heating system)
30 AMP: Washing machine
30 AMP: Auto Dishwasher (I loathe washing dishes)
20 AMP: microwave (& my gas range need ac to operate the electronic controls and piezoelectric system)
20 AMP: Galley counter duplexes
20 AMP: coffeemaker (will reside in a base cabinet on a roll out shelf and eventually will be replaced with my bread machine and slow cooker)
20 AMP: Living room (Any AC lights, receptacles, TV, Home theater/DVD system)
20 AMP: Bathroom (I can run my hair dryer on HIGH!!!)
20 AMP: Bedroom (Any lights, computer/monitor... monitor will double as a TV for movies and a printer)
CONVERTER/CHARGER: for all the 12vDC lighting, 12vDC fans, etc
The computer will be put on a UPS because I have already discovered that the power from our current POS Onan isn't up to running the computer (found that out on the way out here). While on the generator, every time the fridge or freezer (or AC) kicks on, the drain from the compressors start-up surge is enough to kick the computer off. So far, since putting the desktop in the RV, the power in the campgrounds has been pretty good and the computer has only kicked off a few times due to unstable power. But I had a convection microwave (in the pop-up) burn up once in a campground due to unstable power several years ago. I figure a UPS is a better choice for the potentially unstable power system.
If you add every thing up, yes that's more than 30 amps. But everything does not run at that same time. We've sized electrical loads for houses for a long time. We will use probably either GE, Siemans or Square D circuit breakers. Be careful about what breaker box brand you use. We have GE breakers currently. But have seen breakers that are available in GA that we couldn't easily find in TX. I use GE in the Class C but a friend who was rebuilding a vintage RV in CA had the same exact breaker box I did (our RV's were only a few years apart but different manufacturers) but couldn't find the breakers for his box. I ended up giving him a link to exactly the right breaker so that he could order it online. If you are only going to be traveling in a small regional are then you can get away with an odd breaker make but if you are traveling all over, then you need to go with a mainstream manufacturer. If I remember correctly, Siemans will fit their own and another major manufacturers box but I don't remember which (either GE or Square D).