I acquired two surplus phoenix 48/5000 inverters and am planning on using one or both in a tiny home here in the US. I need at least one to be split phase for 110-120v. So the first question is if these are hooked up in parallel, would I only need the one bigger 100a autotransformer ? or it just doesnt work that way and I need one per inverter ..... Second very minor question is will the autotransformer work best splitting 240v down to 120 ? vs say 230 to 115 ? or does it really matter. thanks in advance for any input .