It comprises fixed terminal 42 provided with fixed contact 42 a ; movable armature 44 provided with movable contact 45 ; shaft 44 inserted in the movable armature; sealing container 40 holding the fixed terminal and housing the movable armature and the shaft therein in hermetically-sealed state; contact pressure spring 410 giving contact pressure between the movable contact and the fixed contact; return spring 411 urging the shaft to move away from the fixed contact; operation handle 1 ; shaft pressing piece 56 pressing, in accordance with the operation of the operation handle, the other end of main body of the shaft to move the shaft closer to the fixed contact; and electromagnetic tripping block 6 which makes the movable/fixed contacts open by taking the pressing means away from the other end of the main body of the shaft in case that anomalous current flows through the movable/fixed contacts when they are contacted.
1. A DC breaker comprising:
a fixed terminal provided with a fixed contact;
a movable armature provided with a movable contact which contacts to or separates from said fixed contact, said movable armature being provided with a shaft insertion hole passing therethrough in the approaching/separating direction of said movable contact with respect to said fixed contact;
a shaft having a main body and a deterring part, said main body being inserted in said shaft insertion hole of said movable armature, said deterring part being formed in un-insertable shape in said shaft insertion hole and being coupled with one end of said main body to restrict the movement of said movable armature into the direction in which said movable contact approaches to said fixed contact;
a sealing container housing said movable armature and said shaft therein in hermetically-sealed state and also holding said fixed terminal so that said fixed contact being exposed thereinside;
a contact pressure spring consisting of a coil spring arranged within said sealing container, said main body of said shaft being inserted in said contact pressure spring, said contact pressure spring being configured to resiliently contact at one end thereof to said movable armature to urge said movable armature to approach toward said fixed contact and to give contact pressure between said movable contact and said fixed contact;
a return spring consisting of a coil spring arranged within said sealing container, said return spring being configured to resiliently contact at one end thereof to said deterring part of said shaft to urge said shaft to move away from said fixed contact;
an operation handle;
a pressing means configured to press, in accordance with the operation of said operation handle, the other end of said main body of said shaft to move said deterring part of said shaft closer to said fixed contact; and
a tripping means configured to make said movable contact and said fixed contact open by taking said pressing means away from said the other end of said main body of said shaft in case that an anomalous current flows through said movable contact and said fixed contact when they are contacted.
2. The DC breaker as set forth in claim 1 , wherein mixed gas including hydrogen is enclosed in said sealing container.
3. The DC breaker as set forth in claim 1 , wherein
said DC breaker further comprises a leakage detection means configured to detect electrical leakage of DC electric path in which a contact section consisting of said movable contact and said fixed contact being inserted, and
said tripping means is configured to make said movable contact and said fixed contact open by taking said pressing means away from said the other end of said main body of said shaft when the electrical leakage is detected.
4. The DC breaker as set forth in claim 2 , wherein
said DC breaker further comprises a leakage detection means configured to detect electrical leakage of DC electric path in which a contact section consisting of said movable contact and said fixed contact being inserted, and
said tripping means is configured to make said movable contact and said fixed contact open by taking said pressing means away from said the other end of said main body of said shaft when the electrical leakage is detected.