I placed a second a/c in 2 separate 30amp trailers over the years plunging the second unit into the 20 amp pedestal plug. Never had a problem. Eve had 3 50/amp units over the years with either duel or triple a/c units . On one of the 50 amp units, I tried a split 2, 30 amp plugs to a 50 amp since many Georgia state parks have a twin 30 amp pedestal, I’ve attached the 50 amp units to a pedestal with 2 30 amp outlets and it blew breakers up stream in a main junction box. When I attached 1 of the 30amp legs to the pedestal 20 amp outlet, it blew the 20 amp GFCI. The only way to work it out is to have the new unit on a separate input cord using the pedestal 20 amp and the 30 amp to the dedicated 30 supply.
