ok to plug in 50amp and use a 30amp adaptor??

50 amp circuits tend to be far less used, so there is less chance of a bad connection. I've had times where even with some treatment with De-Ox-It, I couldn't get reliable power from an older 30A connection.

BB_TX wrote:
Just to add. You can tell him that even though he is plugging into a 50 amp service, his TT is protected by its own 30 amp breaker.

exactly.

In fact, this is why most with 30 amp RV's will dogbone into the 50 amp circuit so they only have to flip the breaker inside the RV and not have to run outside in the cold or bugs of night etc to flip the pedestal.

Just to add. You can tell him that even though he is plugging into a 50 amp service, his TT is protected by its own 30 amp breaker.

thanks I,M calling him now.

No problem at all. The adapter is just pulling power off one of the legs of the 50 amp plug.

yes, that's the correct way to do it.