High-safety surge protective device

A high-safety surge protective device comprises:

• a casing (1), at least one overvoltage protection component (3) inside the casing, a release unit (4) used to separate the overvoltage protection component from an AC or DC circuit or an equipment, an arc suppressing apparatus (5) and a box (2) used to suppress electric arc generated while separating the overvoltage protection component from the AC or DC circuit or the equipment, the overvoltage protection component is provided with a first pin (311) connected with a first electrode (8) and a second pin (312) connected with or separated from a second electrode (7) through the release unit, and is mounted on a box;
• wherein:
• the release unit (4) comprises a compression spring (41), a metal dome (42), a slide (43) and a soft conductor (44);
• wherein:
• the slide (43) is mounted inside a slideway of the box, the compression spring (41) is in contact with the slide (43) at one end and fixed on the box at the other end;
• the metal dome (42) is mounted on the slide, its one end is connected with the soft conductor (44), while the other end is welded with the second pin (312) of the overvoltage protection component when it is in normal condition, but when the overvoltage protection component is in abnormal condition and causes this end to separate from the second pin (312) of the overvoltage protection component, an elastic restoring force of the compression spring is applied on the slide which drives the metal dome to move to a first limit wall (202) on the box, the soft conductor (44) is connected with the second electrode (7);
• the arc suppressing apparatus (5) comprises an arc chute assembly (51), a first arc striking sheet (52), a second arc striking sheet (53), a turning block (54) and a torsional spring (55);
• wherein:
• the turning block (54) is a bar-type block with an arc reflector plate (541) provided at one end, a mounting hole (544) at the other end and a spark chamber (542) at a part close to the arc reflector plate, the turning block is attached to a pin roll (204) on the box through the mounting hole (544) at its end and is hinged with this pin roll whose position is such that:
• when the overvoltage protection component is in normal condition, a side at an end of the turning block with the arc reflector plate (541) is in contact with the metal dome, but when the overvoltage protection component is in abnormal condition and causes the metal dome to separate from the overvoltage protection component, the turning block moves to a second limit wall (203) on the box under the action of the torsional spring (55) and the spark chamber (542) on the turning block covers the second pin of the overvoltage protection component separated from the metal dome;
• the torsional spring (55) is mounted on the turning block and is connected with the pin roll (204);
• the arc chute assembly (51) is installed inside the arc extinguishing chamber surrounded by the box (2) and the casing;
• a first arc striking sheet (52) has one end connected with or close to a left end of the arc chute assembly (51) and the other end positioned on the box and close to the first limit wall (202);
• a second arc striking sheet (53) has one end connected with or close to a right end of the arc chute assembly (51) and the other end positioned on the box and close to the second limit wall.