T&T: 30A/50A Y Adapters

[ron barr]

Given the abundance of 30A 1120V only in these parts, and sometimes not that,
I've been looking at the Y adapters to take off two 30A and get 50A 240V.
Expensive little blighters. Somewhere in the dim recesses of my brain I recall
that there is a amperage limitation that still results in making it lower power
than the 50A 240V connection. Anybody know about this and have used one? 
Thanks

Ron Barr
Lady Brookhaven Hatteras LRC 42
Presently lying Kingston NY
KB1LFX