"What age is it, and fuses are still used!" "Fuses are outdated!" These words seem to make sense, but they are also a practical technical problem.
Indeed, in the past ten years or so, no matter in the low-voltage power distribution system design of industrial buildings, civil buildings and outdoor installations, the use of low-voltage fuses has become less and less, and most of them even use low-voltage circuit breakers equally; Correspondingly, the installation of fuses in low-voltage distribution boxes has also been greatly eliminated.
In the application of protective appliances in low-voltage power distribution system, the author thinks this is an inaccurate or incomplete understanding. Therefore, it is necessary to make some comparisons and analysis of fuses and circuit breakers (hereinafter referred to as low voltage), so that these two protective devices can be selected correctly and fairly.
Principle of outdoor drop type high voltage fuse
Outdoor drop-out high-voltage fuses Outdoor high-voltage fuses of 35kV and below are mainly drop-out high-voltage fuses. Mainly used to protect transmission lines and distribution transformers.
This fuse consists of a fixed bracket and a movable fuse tube. The fuse pipe (melt pipe) is made of resin layer rolled cardboard, and the middle is lined with asbestos.
Both ends of the baked wire are crimped with a piece of braided copper wire for connection. It passes through the fuse tube and is fixed on the moving contacts at the upper and lower ends with screws. The movable upper contact is tightened by the fuse and fixed by the upper static The protrusions in the "duckbills" on the contacts are stuck.