Loadbreak-switch Unit uses SF6 gas as Insulating and Arc Distinguishing Medium and applies Compressor-air Distinguishing Principle.
The moving contact of Loadbreak-switch is directly connected with the fixed contact and the fixed contact is fixed on the under rack. The moving contact is connected with operating mechnism through an insulating pole and installed on the upper rack. The piston is used to produce pressure.
When opening, the inner hole of the upper rack and the moving contact make the right relative movement as the upper rack to produce compressed gas which be used to extinguish arc. As soon as the contact are seperated, SF6 gas will be compressed by piston and be sprayed into arc area through gas jet. Then the gas will be cooled down by high pressure and enters the arc area. At current zero, arc temperature will be decreased at arc extinction point and the current will stop moving and then the insulating intensity of SF6 will recover quickly.