Can you give me some clue on definition on 480 volt power of 3 phase and how it work and measure it.
Most 3-phase 480 volt power systems are 480 volts line to line and if the power transformer is a WYE and the neutral is bonded to ground the phase voltages will each read about 277 volts. With ungrounded power systems the line voltages will be 480 volts but the Phase to ground voltages can be out of balance causing insulation stress and component failure. Delta power transformers are a natural harmonic filter and Wye power transformers can be used to supply dual voltage and is ground fault protected. More info is at: