This reply is not for the people that thinking doing things wrong .
It's for those that do not want to have any issues .
The way to use the ratings of components , when using adapters , is to go from larger ratings to smaller - from supply to load .
Just some simple critical thinking can answer many questions , do not use an adapter that allows you to draw more amps through a smaller rated - source 30 to 50 amps , or source 15 to 30 .
Just because someone suggested , and or got away with doing something wrong is to speak plainly just be stupid , not every attempt at doing something wrong is always going to create issues each & every time , other wise we would see many more fires / failures .
There can be exceptions - you know what your doing , keeping a battery charged , not pulling more current from a circuit - by knowing what your turning on and its rating .
One of the issue's is , some one that does not know may turn on a higher rated device on the lower rated circuit - the outlet is the last option to limit how much current is pulled from a circuit - check out a chart on outlets & there rating , the size & orientation of the contacts limit what you can plug in .
Its a crazy world when what is happening here , people that suggest you do things in a unsafe manner - established by engineers creating standards .
" I got away with it and it still works " , these people get bent out of shape when corrected , now will probably just break