what AWG wire do i need to get for the incoming 240 volt shore power wiring?
I'd like to get a 50 foot length.
also, do any of you have shore power hooked up to accept both 110v and 240v (for when 240v isn't available)? if so, do you use separate wires for 110, or do you just have an alternate plug configuration & switch?
6AWG is the standard size for a 50 amp shore cord. It should be four conductor with two hots, neutral and ground.
50 feet will be extremely heavy and very hard to work with. 25-30 foot is usually standard I believe.
Unless there is some drastic need for 240 volt appliances in the coach, most are wired for 120 volts only and the two legs of the 240 volts are used for individual 120 volt circuits.
Sorry, I forgot to answer the rest of your question.
This can get very complicated with the use of either 240 or 120 volts shore power, the wiring of the genset and the automatic transfer switch hookup. I would recommend you get help from some one on the board who is thoroughly familiar with this before you start. I believe Dave Galey has a book that covers it. There have been literally hundreds and hundreds of posts over the past few years on the different boards on this subject. I ereally do not feel qualified to desigh a complete system.
PS I forgot the inverter and battery charger also comes into this design.