I'm building my first HT. I just purchased an APC Smart-UPS 3000 on eBay for $385 shipped. Short outages (less than one minute) are common where I live, so having my entire HT behind a true-sine UPS will be a Very Good Thing. This UPS has a NEMA L5-30P plug, so I would assume it wants a 30A circuit to feed it. An electrician is already coming this week to inspect my house wiring and correct some miswired outlets; I could have him set up a 30A dedicated circuit for me as well. But do I need to do that? I only know enough about electricity to be dangerous , but it seems that it would be easy to combine two 15A circuits into one 30A supply. I'd just have a L5-30R receptacle with two 5-15P power cords screwed to its terminals. Each 5-15P would plug into a different dedicated 15A circuit. As long as the frequency and phase of the AC is the same (which it is, since both 15A circuits come from the same breaker box), is there any reason why I wouldn't want to do this? Other than ensuring I actually use two different 15A circuits, is there anything to watch out for?