A new thermal fuse for network protectors

Fuses made of copper that have been used as additional protection for transformers in low voltage networks in the event that the network protector should fail to operate may blow too quickly on brief overloads, and fail to blow on long-sustained overloads of lesser magnitude. By the combination of a fusible alloy of low melting point and copper blocks that delay the rate of temperature rise the fuse described in this paper provides a time-current characteristic which more nearly approaches the ideal.