Open-core current transformer is suitable for current transformer measurement and microcomputer protection of distribution equipments in *0Kv AC power system.
 It is widely used in not only compact fully insulated ring net switchgears such as ABB-SafeRing/Plus,Uniswitch, RM6/SM6,SVS,GA/GE in Germany, FB in France and SS in Korea,
but also combined substation and cable take-off boxes because of its small volume, light weight, open feasibility and convenient installment. It is very convenient that transformer can be directly installed at connected output and input cables.