Discussion Starter · #1 ·
We have a ups fed from either house or emergency generator power. There is no bypass for maintenance on the ups unit. We were thinking of tying in to another house power 480v breaker, same buss as the ups transformer (480-208/120v) and using a new "external" transformer, same exact size and flavor, same phasing. Then bring both sides of the secondary to a new 208 3 phase panel with 2 breakers and back feeding the buss to main and then feeding the ups panel. Im mainly concerned with both transformer being tied together in parallel and power not being "in phase". The only time we would put both breakers online, is when we "bypass" the ups without dropping out the whole plant, then open UPS primary and secondary to avoid backfeed. Thoughts? I'm rusty on my theory. Kinda hokey I know, don't judge me, I'm just following orders. I drew a schematic, but cannot post it until tomorrow. Thanks.