There is no problem stepping 50Amp down to 30Amp and then again to 15Amp, using 2 adapters...we do it at all the time at home to get the RV's fridge cool before a trip (and not using any propane).
Just BE SURE TO NOT EXCEED the capacity of the house circuit. And remember that house circuit might have other stuff on it inside the house...it all adds up.
Also, check to see if the connections cause a GFCI to pop (GFCI is often used on exterior outlet plugs). A GFCI outlet can be sensitive to the cross-over/connection of the 2 legs on the 50Amp cord that is made within the 50Amp to 30Amp adapter.
Kim and Steve, Mustang LCDR (Ret), '07 Damon Outlaw #1193
I have seen gross intolerance shown in support of tolerance, Samuel Coleridge
WE LOVE OUR OUTLAW RV