No sure where to post this question on this site so I thought I would try here. I have a small 30 unit apartment complex that is uses PTAC units to heat and cool. Before we purchased the building, two new dedicated 240volt breaker panels were installed to service just the PTAC units. We've been slowly replacing the units with new Amana 410 systems and having all kinds of voltage problems and only new units randomly shutting off with "high voltage" errors. What I discovered is the third leg coming into building is a "high leg" 240 volt. (I really am baffelled how when you put the two 120 legs together you get 240 but when you put the 240 and 120 together you only get 240.) I think the issue is we're getting 254v from the pole and the Amana plate says operating range is 199v-253v. Every unit that that has the high leg occassionaly will shut off with "high voltage". Power company wants $7000 to change transformer pole. Electrician said we could put expensive transformer on panel. Odly enough, on the Amana PTAC unit the transformer has a alternate 265v leg we can hook up to for the low voltage. I assume 265v is for 480 power but was just curious if that might be an option or am I just going to blow up the board. Just so unfamiliar with 3phase, high legs and newer electronics. Any feedback or suggestions would be greatly appreciated.