3 Ph Y can be either 208/120V or 480/277V.'Y" is now the most common of the 3 ph LV usage voltage standards.Older power systems were 220V or 440V Delta.Probably older buildings in places like NYC,Chicago,etc were wired for these.I remember some industrial buildings that were old were wired for the old 220 or 440V Delta.Many older motors ran from them.Power companies today favor the "Y" systems-its easier for them to balance loads-and the power factor is better-easier for them to compensate.
Color codes for three phase wiring-I was trying to remember-and trying to look it up in a NEC handbook-the colors can serve two purposes-identifying what voltage is on the three phase circuit-and for polarity.when I put in a 50Kw AM transmitter system-the 50K Tx ran from 480V 3ph "Y".The building was in turn fed with 480V3Ph.The other loads in the building required 208/120V so a transformer was installed to step down the 480V to 208/120V 3Ph "Y".This would run an auxillary 10Kw AM transmitter-and other loads.I remember the colors on the cables were different.
Color codes for three phase wiring-I was trying to remember-and trying to look it up in a NEC handbook-the colors can serve two purposes-identifying what voltage is on the three phase circuit-and for polarity.when I put in a 50Kw AM transmitter system-the 50K Tx ran from 480V 3ph "Y".The building was in turn fed with 480V3Ph.The other loads in the building required 208/120V so a transformer was installed to step down the 480V to 208/120V 3Ph "Y".This would run an auxillary 10Kw AM transmitter-and other loads.I remember the colors on the cables were different.
