I have both my 30AMP trailers here at home plugged into two separate 120VAC 20AMP circuits in my garage... Both my trailers have smart mode on-board converter/chargers in them and this keeps my battery banks charged up normal all the time.
I use the RV30A-15A long Adapter from WALMART to adapt down the RV30 SHORE POWER plug to 120VAC male plug.. DO NOT USE the small RV30A-15A adapters
Then I plug this into a 50-foot 10-GAUGE (10-3) contractor type Extension Cord that is plugged into separate 120VAC receptacles in my garage. You could use a 12-GAUGE (12-3) Extension cord but those 14-16GAUGE you find at Walmart is too small to use. They will get hot burn up your 30A plug.
We use everything in the both RV trailers here including Air Conditioner and microwave. We do have to watch what is on at the same time otherwise we will trip the garage breaker.
We also have one of these RV120VAC plug in VOLTMETERs in each trailer to get a glance of the 120VAC POWER before we turn things on in the trailer. If the readings are NOT in the printed safe zone on meter face we will not try to use and high wattage things.
Like said above having these adapters along with you on trips comes in handy sometimes. I can plug into my 2KW portable generator or into the kids garage when we visit them etc...
Roy Ken