Re: Outback Travel Trailers,
Yes, if you have only 1 air conditioner, you can with care run off of 30 amps or 20 amps (I've done it from 15 amps, although its not really recommended). So of course, you can do the same thing with 2 A/C, just turn one of them off. But a place which is designed to be cooled by 2 is less comfortable cooled by 1... What we do is turn off the bedroom air during the day and the living room air during the night. Has worked so far, although we try to avoid places so hot that wouldn't work
I personally like 50amps, but I wouldn't get it 'just to have the option'. If my trailer could not use more than 30 amps, I can still get an adapater to plug it into a 50 amp socket. But seeing as 50amps is so much more versatile than 30 amps, I don't know that I'd get another trailer which used only 30.
And speaking of adapters, there is a box available which plugs into 2 outlets to give you the sum of them (30 + 30 or 30 + 20). In order to use it, the 2 outlets MUST be out of phase, so along with the box, make sure you have a 120/240v test light and know how to use it without killing yourself.