ECN Forum Forums General Topics of the Trade General Discussion Area Ok theorists, help me out

For and ANSI-standard 480∆-208Y/120V transformer served from 480Y/277V, there is 90° between X1-X0 and H2-N. For 120V and 277V, the difference figures at 302V. If the actual voltages were ~3% high, the difference could be 310V.