I have upgraded my Vista 27N so that in addition to the standard OEM AC power arrangement, I can:
Off-load the Air Conditioner and Converter-Charger to an additional power box. This power box is fed by a 25' 30 Amp Extension Cord.
Off-load the Microwave / Hot Water Heater to a 25' 12 gauge 15 Amp Extension Cord.
I take advantage by manually moving plugs to different sockets in the basement.
I modified a 50 Amp Plug to dual 30 Amp Receptacle adapter with a fuse protected 15 Amp outlet spliced into the L2 30 Amp Receptacle cord.
I found that I often camp in RV camp spaces with a 50 Amp Plug that is no additional cost to use, so I created this setup to take advantage. Plug the adapter into the 50 Amp pedestal outlet. Run the OEM shore cable plus the 30 Amp extension cord and the 15 amp extension cord to the basement.
I was already carrying the extension cords. I was able to mount the box and plugs in un-used space in the top part of the basement electrical compartment. Total parts cost under $ 100.
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2nd mod, shown in blue: I replaced the Xantrex 1000 Watt inverter with a 3000 Watt Pure Sine Wave Inverter. The large size is mainly so it can handle the starting current of the residential microwave I upgraded to in my RV. I have 3 branch circuits fed from the inverter via home-made transfer switches made using 20 A DPDT Appliance Relays and plastic electrical boxes.
I also have a home-made manual transfer switch panel for a 4th circuit that powers the refrigerator AC outlet using a 20 A DPDT Switch, a metal switch plate, and a plastic electrical box. I use this when traveling in the RV with the propane off. When traveling I turn on the inverter and put the refrigerator on the inverter with the manual switch. The chassis alternator keeps the coach batteries charged, making up for the 12 volt power the inverter uses powering the refrigerator.