Fuse refers to an electrical appliance that uses the heat generated by itself to fuse the melt and disconnect the circuit when the current exceeds the specified value. The fuse is to melt the melt with its own heat after the current exceeds the specified value for a period of time, so as to disconnect the circuit; A current protector made using this principle. Fuse is widely used in high and low voltage distribution systems, control systems and electrical equipment. As a protector for short circuit and overcurrent, it is one of the most widely used protective devices.
Because different electrical equipment is used, the selection principles of its capacity and size vary greatly. In practice, it is necessary to select and configure fuses for circuit protection in strict accordance with the regulations.
For light load starting or short starting time, such as starting time less than 3s or fan (machine) motor, it shall be configured according to (4~5) times of the rated current of the motor; For motors with a starting time of 4s to 8s, or with heavy loads such as water pumps, since the starting current is up to about 6 times of the rated current, the size of the fuse (fuse) configured shall be set as (5 to 6) times of the rated current of the motor; For motors with a starting process of more than 8s or longer and frequent starting, the fuse (fuse) shall be configured as (5~7) times the rated current of the motor.
