50 amp female to 30 amp male shore power cord question

JimInMich wrote:
Or does it all power up and I just cant use both A/C's?

That pretty well sums it up. With a 30 amp supply you get one leg at 30 amps or 3,600 watts of power. With a 50 amp supply you get two legs at 50 amps or 12,000 watts of power. With a 30 to 50 dogbone, both 50 amp legs in the MH will have power but will have to split the 30 amps or 3,600 watts.