摘要:
Electrical switchgear comprises a fixed input contact (59), a fixed output contact (85) and a fixed auxiliary contact (82). A movable contact (83) is movable from a closed position wherein it connects the input and output contacts (59, 85) into an open position wherein it connects the auxiliary and output contacts (82, 85). An arcing electrode (76) having a substantially circular periphery is connected to the input contact (85), and is radially surounded by a coil (78) having a conductive ring (77) on its inner circumference. The ring is radially spaced from the arcing electrode (76) and the parts are arranged so that when the movable contact opens an arc is formed between the moveble contact (83) and the arcing electrode (76), the arc commutates to a location between the arcing electrode (76) and the conductive ring (77) and arcing current flows through the coil and produces a magnetic field which causes the arc to rotate and become extinguished. The arcing electrode (76) is permanently electrically connected to the input contact (59), and the coil winding is electrically connected between the conductive ring (77) and the auxiliary contact (82).
摘要:
Electrical switchgear comprises a fixed input contact (59), a fixed output contact (85) and a fixed auxiliary contact (82). A movable contact (83) is movable from a closed position wherein it connects the input and output contacts (59, 85) into an open position wherein it connects the auxiliary and output contacts (82, 85). An arcing electrode (76) having a substantially circular periphery is connected to the input contact (85), and is radially surounded by a coil (78) having a conductive ring (77) on its inner circumference. The ring is radially spaced from the arcing electrode (76) and the parts are arranged so that when the movable contact opens an arc is formed between the moveble contact (83) and the arcing electrode (76), the arc commutates to a location between the arcing electrode (76) and the conductive ring (77) and arcing current flows through the coil and produces a magnetic field which causes the arc to rotate and become extinguished. The arcing electrode (76) is permanently electrically connected to the input contact (59), and the coil winding is electrically connected between the conductive ring (77) and the auxiliary contact (82).
摘要:
A fuse for an alternating current ppower circuit. The fuse comprises an input terminal (4), a first contact (5) electrically connected to the input terminal, an output terminal (9) and a second contact (8) electrically connected to the output terminal. A fusible element (11) electrically connects the first and second contacts and completes a normal electrical path between the input and output terminals. An arcing contact (6) is positioned in relation to the first contact (5) so as to form a potential arc path between the first contact and the arcing contact, along which path an arc will become established after the fusible element breaks in response to fault current. The arcing contact (6) is electrically connected to a third terminal (41) and is electrically isolated from the output terminal (9). The fuse can be used in a single phase circuit to reduce let-through energy to a load under fault conditions, or in each phase of a multi-phase circuit to break the supply to all phases in response to a fault on any one phase.
摘要:
A fuse for an alternating current ppower circuit. The fuse comprises an input terminal (4), a first contact (5) electrically connected to the input terminal, an output terminal (9) and a second contact (8) electrically connected to the output terminal. A fusible element (11) electrically connects the first and second contacts and completes a normal electrical path between the input and output terminals. An arcing contact (6) is positioned in relation to the first contact (5) so as to form a potential arc path between the first contact and the arcing contact, along which path an arc will become established after the fusible element breaks in response to fault current. The arcing contact (6) is electrically connected to a third terminal (41) and is electrically isolated from the output terminal (9). The fuse can be used in a single phase circuit to reduce let-through energy to a load under fault conditions, or in each phase of a multi-phase circuit to break the supply to all phases in response to a fault on any one phase.
摘要:
A three-phase electrical ring main unit comprising a lower chamber module (30) having a wall structure formed from insulating resin material; three input contacts (35), one for each phase, mounted within the lower chamber; three lower switching contacts (37), each mounted within the lower chamber for movement between different switching positions; insulating closure means (55) closing the top of the lower chamber; three output contacts (49), one for each phase, carried by and exposed on a lower face of the closure means; three busbar contacts (59 to 61), each electrically connected to a respective output contact, carried by and exposed on an upper face of the closure member (55); an upper chamber module (31) having a wall structure formed from insulating resin material; means (32) securing the upper chamber above the lower chamber; three tee-off contacts (85), one for each phase, mounted within the upper chamber; and three upper switching contacts (83), each mounted in the upper chamber for movement between different switching positions; one switching position of the lower switching contacts effecting electrical connection between the input contacts and their associated output contacts; and one switching position of the upper switching contacts effecting electrical connection between the busbar contacts and their respective tee-off contacts.
摘要:
A three-phase electrical ring main unit comprising a lower chamber module (30) having a wall structure formed from insulating resin material; three input contacts (35), one for each phase, mounted within the lower chamber; three lower switching contacts (37), each mounted within the lower chamber for movement between different switching positions; insulating closure means (55) closing the top of the lower chamber; three output contacts (49), one for each phase, carried by and exposed on a lower face of the closure means; three busbar contacts (59 to 61), each electrically connected to a respective output contact, carried by and exposed on an upper face of the closure member (55); an upper chamber module (31) having a wall structure formed from insulating resin material; means (32) securing the upper chamber above the lower chamber; three tee-off contacts (85), one for each phase, mounted within the upper chamber; and three upper switching contacts (83), each mounted in the upper chamber for movement between different switching positions; one switching position of the lower switching contacts effecting electrical connection between the input contacts and their associated output contacts; and one switching position of the upper switching contacts effecting electrical connection between the busbar contacts and their respective tee-off contacts.