Applicable to power distribution systems in power plants, petroleum, chemical, metallurgy, textile, high-rise buildings and other industries. In large power plants, petrochemical systems and other places with a high degree of automation that require an interface with a computer, as a three-phase AC frequency of 50 (60) Hz, rated working voltage of 380 V (400) V, (600) V, rated current up to 4000 used for power distribution, motor centralized control, and reactive power compensation in power generation and power supply systems below.