The product adopts a combination bolt connected structure.The sizes of the mounting hole are based on the mode of E=20mm and the inner structure are treated with galvanization.The cabinet is divided into 3 areas:the generatrix area,cable(electronic) equipment area,and cable area which ensures mo electrification units exposure to air.All the operation handles are outside the cabinet thus can operate the switch favorably without opening the door.The product adopts 3 phase 5 lines supply power.The neutral cable(N) and grounding cable(PE) are connected under the lower side of the side of the cabinet.There are reliable grounding cables in the tank.The product is in accordance with IEC439 international criterion and GB7251-87 national criterion.The protection grade is high.It can be used in electricity generation or distribution systems with 660V or less working voltage as a charge center,motor control center.It can also be used in ship,offshore platform and nuclear power plant etc.