At normally working via 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 moving contact has no tightened strength 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 sticks 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 lengthened in arc-extinguishing enclosure gap and meanwhile arc-extinguishing explode gas to blow off the arc during current passing zero.
Note: Other marks refer to the following conditions
- a) The product that has been improved greatly, but not the developed product needs to be distinguished from the original model, so, it is marked with A, B, C ….
- b) The product that is combined with other functional units under the same variety, it is expressed with the upper case letter of
Chinesephonetid alphabet of functional unit, for example,
F—With load breaking device
- c) The derived product that is applicable for the special environment conditions is expressed with the following codes and brackets, for example,
Th—Damp-hot zone type
TA—Dry-hot zone type