Be careful out there people, I just ran across a 3 phase rooftop unit with a single phase disconnect installed on it. Third leg was hot all the way from breaker down stairs right to 1 leg on compressor. Volts were everywhere and I was lucky I checked with meter before touching. Even more confusing was that unit used a single phase contactor which made it appear even more like a single phase that a 3 phase. Unit is wired correctly with new disconnect.