The invention relates to a three-
station vacuum arc extinguish chamber for isolated grounding, which is mainly applied to medium-
voltage power switch equipment and comprises an isolated outer shell, a fixed cover plate, a movable cover plate, a fixed end conducting rod, a movable end conducting rod, a fixed contact, a movable contact, a corrugated
pipe and a protective cover, wherein the fixed cover plate and the movable cover plate are respectively arranged at the upper end and the lower end of the isolated outer shell, the top of the fixed end conducting rod is welded with the fixed cover plate, and the bottom of the fixed end conducting rod is welded with the fixed contact; the protective cover of the corrugated
pipe is arranged outside the corrugated
pipe; the movable contact is formed by
welding an isolated contact and a movable grounding contact; the middle of the isolated outer shell is provided with a grounding ring, the upper surface and the lower surface of the grounding ring are connected with the isolated outer shell through a sealing ring, and the upper surface of the grounding ring is welded with a fixed grounding contact; the bottom of the fixed cover plate is welded with a fixed end isolated shielding cover, a middle isolated shielding cover is arranged on a bead at the upper part of an inner cavity of the isolated outer shell, and a grounding isolated shielding cover is arranged on the grounding ring; one end of the movable end conducting rod is welded with the movable grounding contact after penetrating through the cover plates, the corrugated pipe, the grounding isolated shielding cover, the middle isolated shielding cover and the fixed end isolated shielding cover, and a movable end
voltage-sharing cover is welded on the movable cover plate. The invention has the advantages of simple structure and low cost.