Drop-out fuse cutout and load switching fuse cutout are of outdoor used high voltage protective device. They are connecting with incoming feeder of distribution transformer or distribution lines it mainly protect transformer or lines from shod circuit and overload. And on/off loading current. Drop out fuse cutout is composed of lnsulator supports and fuse tube. Static contacts is fixed on two sides of insulator support and moving contact jS installed on two ends of fuse tube.
Fuse tube is composed of inside arc-extinguishing tube, outer phenolic compound paper tube or epox glasstube. Load switching fuse cutout provides enforedelastic auxiliary con.
Al normally working via fuse link tightened the fuse tube is fixed to form up of close position. 1n case system occure faults, fault current result in fuse melt immediately and take place electric arc.
Guishing tube being heated and explode a lot of gas. This will produce high pressure and blow off the arc along with tube. After fuse link melt moving contact has no tightened shrength again, mechanism is locked and fuse tube drop out. Cutout now is in open position.
When it needs to switch-off during cutout loading, operator shall via insulating operating bar pull the moving contact, at its beginning main contact and auxiliary static contact is contacted still. Whiling pulling the auxiliary contact is separated between auxiliary contacts there occur electric arc and the arc will be length in arc extinguishing enclosure gap and meanwhile arc-extinguishing explode gas to blow off the arc during current passing zero.
