Tobe connect with incoming feeder of distribution lines.It mainly protect transformer or lines from short circuit and overloading current.Drop-out fuse cutout is composed of insulat insulator supports and fuse tube,static contacts is fixed on two sides of insulator support and moving contact is installed on two ends of fuse tube. Fuse tube is composed of inside arcexting tube.Outer phrnolic compound paper tube or epoxy glasstube.Load switching fuse cutout provides enforced elastic auxiliry contacts and arc-extinguishing exclosure for switching on-off loading current.

At normally working condition, via fuselink tightned the fuse tube is fixed to form up of close position.In case system occure faults,fault current result in fuse melt immediately and take piece electric are,which let arc-extinguishing tube being heated and fexplode alot of gas,Th-os will produce high pressure and below of the are along with tube.After fuselink melt moving contact has no tightened strength again,mecganismis locked and fuse tube drop out.Cutout now is in open position. When it needs toswitch off during cutout loading,operat-or shall via insulating bar pull the moving contacts there occur electric arc and the arc will be lengthened in arc-extinguishing enclosure gao and meanwhile arc-exting explodes gas to blow off the arc during current passing zone.