Hi all. I have an older motorhome with 30-amp service. As a result, there is a switch above the microwave that will allow you to run the microwave OR the front a/c unit, but not both. The rear a/c unit is wired directly to the generator and therefore only runs when it's fired up. The generator feeds the breaker panel, too, so the only way to run both a/c units currently is with the generator running. This is fine with me (and a required limitation given the 30-amp service), however what's not fine is only being able to run the front a/c unit under shore power. I could easily install a switch after the existing micro/AC switch to switch between the a/c units. BUT, that would mean disconnecting the generator from the rear unit. What sort of switching arrangement could I install to safely add the ability to power the rear a/c unit under shore power while preserving the ability to run both units off of the generator?

I am helping wire an old barn for clasic car storage. The building is 60 ft. x 55 ft. with a roof that pitches from 12 ft. at the eves and 20 ft. in the center. The building only has 100 amp service located in one corner. I have run 50 amp service to the opposite side of the building and am servicing my RV from that. Now the problem. We will be installing 12 light fixtures that require 3 amps on full load. I am wiring them to where I can fire four lamps off one switch and two lamps off another. That switching will be used for all 12 fixtures. I plan on using two 20amp 120 volt breakers for this service. My plan is to put a subpanel near where the 50 Amp plug is. Break the service there and put the full 50 amp service from the main panel in this box. Then put a 50 amp breaker on the RV service, two 20 amp breakers for the lighting and a breaker that will service a welder and compressor. Due to the 100 amp service with 50 amps on the side that will service the lights, RV, compressor and welder, I am thinking that these circuit breakers will need to be used as on/off switches for load control. Kicking the RV off line when the welder and or compressor are in use. The RV will very seldom if ever pull a full 50 amps. The electrical outlets and will use two 20 amp breakers from the main panel. Does all of this make sense? If it does than let's go to the next question. How do I wire (wire size and circuit breaker) for the welder and compressor?