im not sure that those two items are related. i believe most power converters / chargers only need 15/20 amp service to run.
the more dc
amps your power converter produces affects how fast it can charge batteries and the 12v dc
load it can support. Bigger is better
50 amp service implies that you will have an AC
breaker box in your bus that has 2-120v hot legs, a neutral, and a ground. 4 wires - your connection at the campground pedestal. that is what the others are talking about. the cord
the converter will only need 3 AC
wires to power the bus 12volt dc
system. 1 hot leg, 1 neutral, and 1 ground. it would be 1 circuit or breaker off of your 50 amp service panel
your AC needs dictate the size of panel you need. most household appliances needed while camping could run off 20 amp service, if you add an air conditioner, you need 30 amp service, running 2 air conditioners means you need 50 amp service.
this is what i have :
PD9180A Electronic Power Converter