I did a little digging and found a 2022 Fuel 287 FS. Reading thru it, it lists your 15K ducted AC, and also states prewired for a second AC, just for your FWIW installing your second one.
We factory ordered our 44+' CY with 3 ACs, but we only use 1 of them 5% of the time....so I made the same mistake as you, in a way.
All 3 of our 15K ACs draw 11 amps each after starting, so a 30A service **COULD BE USED MARGINALLY** if all occupants knew how to conserve those extra amps (not many know the tricks to do so..lol). I'm not condoning a second AC on 30A for you....but the wife and I are in the know to make it work. Soft Starts are also very useful.
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