This type of discharge coil for oil-immersed type products, in the suitable rated frequency 50 h z, rated voltage 10 kv and below power system. Connected in parallel with the high voltage parallel capacitor group, when the capacitor Banks and department System after disconnecting to within 5 s will be the remaining voltage on the capacitor Banks fell to a safe voltage. In normal operation , the secondary winding voltage indicator can be done, if users have special requirements, can bring the residual voltage winding, Play a role of relay protection.