In addition to other managerial duties I serve as the Facilities Engineer for a 250,000 ft*sq building and we've got 6,500 Amps of 480V three phase service coming in. In addition to motors and step down transformers running off the 480V single legs of it are used to operate the lighting which is 277V.Help: Can you give me some application of 3 phase system..other that motors and transformers..