4. electrical 3-phase 4-wire) electrical system electrical 3-phase 4-wire this system both single phase 220 volt system and three-phase 380 v systems commonly used in larger cities, local prosperity and use electric.
4) Power 3-phase, 4-wire three-phase four wire power system is the second power system is 220 volts, single phase and three phase 380 volt system used in large urban local prosperity. And use a lot of electricity
4) electrical 3 phase 4 wire electrical 3 phase 4 line. This power either 2 system is the system of single phase voltage and phase 220 system 3 380 v. popular in big cities local prosperity. And use electricity.