... the enclosure is of IP4X.1.2.The primary switch may be provided with VD4 vacuum circuit breaker and C3 series ... domestic vacuum circuit breakers (such as VS1, VH1, VK, ZN28) may also be provided in lieu of the same foreign products ... 3.6-12 kV 3-phases AC 50 Hz. It may receive and distribute power, and control, monitor and protect circuits. It ...