fuse cutout

Drop-out fuse cutout and load switching fuse cutout are for outdoor used as high voltage protective device. Drop-out fuse cutout is made up of insulator supports, fuse tube, movable and fixed contacts. Of which the fixed one is fastened on two sides of insulator support and movable one is installed on two ends of fuse tube. Fuse tube is composed of inside arc-extinguishing tube, outer phenolic compound paper tube or epoxy glass tube. Load switching fuse cutout provides enforced elastic auxiliary contacts and arc-extinguishing enclosure for switching on/off loading current.

At normally working, fuse link tightened the fuse tube is fixed to form up of close position. In case system occur faults, fault current result in fuse melt immediately and take place electric arc, which let arc-extinguishing 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, movable contact has no tightened strength again, mechanism is locked and fuse tube dropout. Cutout now is in open position. When it needs to switch off during cutout loading, operator should use insulation operating bar to pull the movable contact. At its beginning movable contact and auxiliary fixed contact are contacted still. Pulled more, the auxiliary contacts are separated, at the same time there occur electric arc and the arc will be lengthened in arc-extinguishing enclosure gap meanwhile arc extinguishing explode gas to blow off the arc during current passing zero.

Normal running circumstances

A.The surrounding temperature is no higher +40℃, no lower than -40℃.

B.The altitude does not exceed 1000m

C.Maximum wind speed does not exceed 35m/s

D.The earthquake intensity doesn’t exceed 8 degrees

 

Unsuitable service conditions

A.Area with danger of inflammation or explosive

B.Area with intensive shake or shock

C.Area with conductance, chemical gas as well as badly polluted & salt fog.