Can a reverse Y adapter be used with my 38BR? The biggest concern I have heard of is whether the power must be 2 phase. I am not talking about having 220 power. As far as I know, I do not have any 220 appliances. Note: I started my career as an electric technician so no problem with getting technical.
If you mean an adapter where a 30 amp outlet feeds one leg of your 50 amp connection, and a 20 amp outlet feeds the other; that device might work, but has fallen out of favor in recent times. Most campsites feed their 20 amp outlet through a GFCI, which most often trips with such an adapter.
If your second a/c unit is not tied into the main thermostat and duct work then the best solution is to run a separate line to the second a/c unit so that you can run it individually off of the 20 amp plug in the junction box.
George & Lynda
College Station, TX
2011 Cruiser CF335SS Patriot
'04 Dodge 2500 Quadcab CTD
That type of adapter feeds the single "hot" of the 30 Amp outlet to BOTH "hots" of the 50 Amp plug. Very likely the two ACs, plus converter and anything else running off of 120 volts would likely trip the 30 Amp breaker at the pedestal. Most attempts at running two ACs in such a situation involve using the pedestal's 20 amp outlet for the second AC, either by some adapter or by separate wiring.
I'm not sure that is what's called a reverse Y adapter.
It would be helpful if he/the OP would state which one he is referring to.
I don't fully understand them and I don't see how you could operate two AC units off of them. Especially if you are reversing from 50 to 30 amps. Seems like that was his concern.
That is just a 'dog bone' adapter. It's purpose is to provide power to all circuits in a 50 amp RV when only 30 amp outlets are available. While power is limited to just 30 amps, it is better to combine both hot legs so the owner can use any combo of items up to that 30 amp max.