DownTheAvenue wrote:
There may be an advantage. The 30 amp receptacle is most used and often is worn, so the plug fits loosely. This can cause a poor connection, arcing, and overheating of the plug. Using the less used 50 amp receptacle which is often in better shape, you may avoid the overheating situation.
I carry an adaptor for just-in-case. Had to use it a few months back at a site in Chippokes State Park, Virginia. The 30 amp receptacle was installed upside-down from the usual orientation. It caused my EMS to hang in the air where it's weight would pull the plug out of the box. Used the adaptor to connect to the normally-oriented 50 amp receptacle. It saved our trip because the park was sold out that weekend and we could not have changed sites.