Patent ID: 6430018
Filing Date: 2002-08-06
Classification: H01T

Abstract:
A three-electrode-discharge surge arrester having two discharging parts of a pair of line electrodes, the two discharging parts opposing each other and defining a gap therebetween; a ground electrode disposed between said two discharging parts and provided with a penetration hole in the center thereof; and two cylindrical insulating housings between each of said line electrodes and said ground electrode,wherein each of said two discharging parts has a substantially conical shape; each of inner surfaces of upper and lower parts of said penetration hole is substantially funnel-shaped, in accordance with said substantially conical shape; and oblique parallel gaps for a primary discharge are formed between said inner surfaces of said upper and lower parts of said penetration hole and said two discharging parts, respectively, wherein parallel gaps for a secondary discharge are formed between peripheral parts of said ground electrode around said penetration hole and peripheral parts of said pair of line electrodes, respectively, each of the peripheral parts of said pair of line electrodes opposing each of said peripheral parts of said ground electrode around said penetration hole, and wherein each of said oblique parallel gaps is formed narrower than each of said parallel gaps.