Newer motor homes and larger travel trailers typically have 240V 50A
supplies, so the RV parks are more and more equipped with this power.
This gives a capacity of 12KW in place of the 3.6KW available from a 120V
30A supply.
A converter connector is available to plug a 30A cord into a 50A
receptacle. It simply connects the 30A plug to the neutral, one side of
the 240V hot (which is 120V to earth ground), and to the ground wire,
leaving the other side of the 50A supply unused.
The land power breaker is 50A instead of the 30A called for by 120V 30A
trailers and MHs but the 30A breaker in the RV's own panel will still
trip if there is an overload.
If a 50A RV is stuck with a 30A land power supply and a converter
connector is used only one side of the panel in the RV will be live. No
240V equipment will operate, and nothing on the dead side of the RV panel
will work.
Al