A good place to read up on all of this is NO SHOCK ZONE on-line...
The 50AMP Service is actually for the 50A named power distribution centers which is actually two zones of 120VAC CIRCUITS which are each protected by a 50A Circuit breaker...
Looks something like this...
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The big plus here you can run two separate air coditioners under separate zones...
This is what you see when you measure across the RV 50AMP Service Plug...
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Most of the 50A trailer only use the two 120V 50AMP zone with only some of the high end trailer that want to have washer and dryers would do special wiring to have the 240VAC actually go into the trailers...
Messing with the rewiring of the 50A wiring to use 240VAC inside your trailer can get you into trouble and you may burn up some of the 120VAC appliances... best to leave all of that with pros... Goof idea to have a licensed electrician that has insurance... If he burns up your 120VAC appliances his insurance will replace... If you and your neighbor burns up the 120VAC appliances in your trailer guess who gets that bill hehe...
Here is how a typical power pedestal is wired up at the camp grounds...
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If you was more specific on what you wanting to do you might get some better answers from all of us... Lots of 30A and 50A service folks on here with great info to pass along...
I am a 15A/20A/30A guy here with my off-road popup trailer... Most of the time I run my things off of the batteries and then usually at 8AM each morning when allowed I will hook up my trailer to my 2KW Generator and let it charge the batteries with about a three generator run time using my on-board Converter charger unit...
When at home I plug my 30A cable into the garage 20A service using a RV30A to 15A long adapter like this... Got this from WALMART I think...
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Check out "NO SHOCK ZONE" on the Google - lots of good info there...
Roy Ken