The dual element fuse is a major accessory for overcurrent protection of oil-immersed padmount transformers in power distribution systems. It is used in series with the backup fuse ) to form a "two-stage protection" solution. The dual element fuse protects the transformer from faults or overloads on the low-voltage side from both current and temperature aspects. The backup p fuse is used to protect the transformer from internal faults (coil short-circuit faults, etc.). The standard ampere-second curve can accurately match the upper and lower fuses and circuit breakers. The dual element fuse is installed in the fuse barrel, which is easy to replace, simple to install and reliable in operation. Therefore, it is widely used for high-voltage side protection of American padmount transformers.