30 amp coach - 50 amp site

[MOHOMER729]

The 50 amp breaker would give short circuit protection......... Maybe.  The 30 amp cable would not have adequate overload protection.

 

[kdbgoat]

MOHOMER729- the cable will never see an overload because the load from the RV goes through a 30 amp breaker before going into the shore power cord. The 30 amp main will trip first before overloading the cord. Have you ever plugged an 18 ga. household extension cord into a 15 or 20 amp receptacle in your house? That is more dangerous than using an adapter for powering a 30 amp RV from a 50 amp receptacle.

 

[Bill N]

I have actually used my adapter just like it several times at sites with both 30A and 50A. 
I find that the 30A outlets are very often used much more and so they get tired and loose

and often are fried on one or more of the legs.