Drop-out fuse cutout and load switching fuse cutout are outdoor high voltage protective device. To be connected with incoming feeder of distribution, transformer or distribution lines. It mainly protect transformer or lines from short circuit and overload and ON/OFF loading current. Dropout fuse cutout is composed of insulator supports and fuse tube. Static contacts is fixed on two sides of insulator support, moving contacts is installed on tow ends of fuse tube. Fuse tube is composed of inside arc extinguishing tube. Outlineer phenolic compound paper tube or epoxyglasstube. Load switching fuse cutout provides enforced elastic auxiliary contacts and arc shield for switching on-off loading current. At normally working condition, fuse link tightened the fuse tube is fixed to form up of close position. In case system occur fault, fault current will let the fuse melt immediately and electric arc will be brought, which let arc extinguishing tube being heated and resolved a lot of gas. This will produce high pressure in the tub, and blow along with the tube, and then the arc will be extended and extinguished. After fuse link melt, moving contacts has no tightened strength, locking device release the fuse, fuse tube drop out, cutout now is in open position. When it needs to switch off during cutout loading, use the insulating operating ball pull the moving contact, now main contact and auxiliary static contacts is still in contacting. Whiling pulling, the auxiliary contacts is separated, and then electric arc occurred between auxiliary contacts, arc is extended in the arc shield, at the same time the arc shield explode gas, when the current overload, let it extinguished.
