The current sensing BON fuse is a main accessory of the overcurrent protection device of the oil-immersed padmount transformer in the power distribution system. It is used t o isolate the fault current to protect the equipment, or to isolate the faulty equipment to protect the power system. It can be used for single-phase transformers, self-protected transformers or other distribution equipment not exceeding 500kVA, and can also be u sed for three-phase transformers not exceeding 1500kVA.

Overcurrent protection fuses are generally used in conjunction with backup fuses (ie ELSP) to form a "two-stage protection" scheme in which the current sensing fuse and the backup fuse are connected in series. The current sensing fuse performs overload pro tection and secondary side protection, and the backup protection fuse is used to dry protect the internal fault of the transformer (coil short circuit fault, etc.).

The current sensing fuse is installed in a plug-in fuse barrel, which is very convenien to replace, simple t o install and reliable in operation. Therefore, it is widely used for high-voltage side prot ection of ANSI Padmount transformers.