A disconnector for an overvoltage protector is equipment that disconnects a circuit when the overvoltage protector may fail in a short circuit mode. The disconnector and the overvoltage protector are connected in series. A fuse or a circuit breaker is normally used as a disconnector. However there are problems with both methods. A fuse is not recyclable once it goes out. Even a circuit breaker is resettable, a lightning surge current causes a switchgear of circuit breaker to open unnecessary. This malfunction spoils the overvoltage protective function which eliminates a lightning surge current into an instrument. If the problem which a switchgear of circuit breaker comes floating can be solved, even when a lightning surge current flows through it, an instrument can be protected by the overvoltage protector. This paper presents several approaches preventing circuit breaker type disconnectors from the malfunction.
A disconnector for an overvoltage protector is equipment that disconnects a circuit when the overvoltage protector may fail in a short circuit mode. The disconnector and the overvoltage protector are conected in series. A fuse or a circuit breaker is normaly used as a disconnector. However there are problems with both methods. A fuse is not recyclable once it goes out. A circuit breaker is resetable, a lightning surge current causes a swich of circuit breaker to open unnecessary. This malfunction degrades the overvoltage protector function which eliminates a lightning surge current into an instrument. If the problem which a switch of circuit breaker comes floating can be solved, even when lightning surge flows through it, an instrument can be protected by the overvoltage protector. This paper presents a way of preventing an circuit breker type disconnentor from the malfunction.
