Electrical Issue 30 vs 50 Amps

CA Traveler wrote:
Did you really just plug in one of the male plugs? That creates a potentially dangerous situation as the other male plug could have 120V AC on it due to feedback in the rig. DON'T DO THIS.

Was the other leg plugged into a GFCI circuit as it would have tripped and caused what you have observed.

I know they sell these adapters but you should have in depth knowledge of their shortcomings and there are several. And unless you have that knowledge they my advice is to not use this adapter.

Instead go to Wallmart, etc and buy a 30A male to 50A female adapter (2 ends not 3 ends) and you will have 120V on both 50A hot legs. You will of course be limited to 30A total by the pedestal 30A CB. This is a very common and standard RV adapter.

At the same time buy a 20A male to 30A female and then you can also plug into a 20A circuit. About $20 for both adapters.

Only one buss bar would have been HOT so backfeeding would have required some non-normal/unusual connection .......99% not going to happen (nothing is 100% cause somebody WILL do something)

OP........
You stated (2) 30A male to (1) 50A female in original post now you are talking about a 30a/15a to 50a adapter :H

30/15 will not work ......usually due to 15a being GFCI along with possible power pedestal wiring issues. Same circuits/neutral etc.
Just forget about it....return it. NOT what you want!

Just get a 30A to 50A adapter.
The 30A uses a jumper inside plug to feed both 50A legs so both busses in AC Panel will be HOT