Hi, Mike Sokol from the No~Shock~Zone here. There's so much confusion about 120 or 240 volts for a 50-amp RV service that I just published this article showing how it actually hooks up, and how NOT to do it.
https://rvtravel.com/can-i-use-a-wel...-amp-rv-power/
As a number of you have already alluded to, most RVs in the USA don't actually use any 240-volt appliances internally. So while there are two legs of 120-volt power going into your RV from a properly wired pedestal which COULD be wired as 240-volts from leg-to-leg, you can really treat it as a 100-amp/120-volt service for wattage calculations and such.