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AssigneeABB AB
InventorsESA VIRTANEN, TAPANI TIITOLA, VESA VIRTANEN
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The invention relates to a circuit breaker, which is in a fault situation arranged to disconnect an electrical apparatus, such as a distribution transformer, from an average voltage network or a high voltage network at each terminal. At least one lik-spring mechanism (9 to 12) is arranged at a shaft (6) of the circuit breaker for holding contacts (1, 2) live in connected position and for pushing them apart to the extreme disconnected position when disconnected, while the shaft (6) is brought over the dead spot of its turning. For an initial release the shaft (6) is at each phase provided with a lever arm (8) each lever arm at each phase being arranged to turn by means of a trip pin (19) of a striker (18) of a high voltage fuse (17) the shaft (6) of the circuit breaker and thus the moving contacts (1) of all phases from said connected position over the dead spot of turning said shaft
Circuit breaker, which is in a fault situation arranged to disconnect an electrical apparatus, such as a distribution transformer, from a medium voltage network or a high voltage network at each terminal, and which circuit breaker comprises at each phase at least one fixed contact (2) and a moving contact (1) to be engaged with and disengaged from the fixed contact, the circuit breaker being simultaneously electrically connected in series with a high voltage fuse (17) situated at each phase, wherein at least one link-spring mechanism (9 to 12) is arranged for holding the contacts (1, 2) live in connected position and for pushing them apart to the extreme disconnected position when disconnected, while the shaft (6) is brought over the dead spot of its turning by trip means (18, 19) characterised in that
Circuit breaker according to any of the preceding claims, characterised in that a trough (20) is arranged around the circuit breaker to keep the circuit breaker in the dielectric liquid.
Circuit breaker according to any of the preceding claims, characterised in that a high voltage fuse (17) is arranged at least partially inside a feedthrough insulator (16), which is fastened to the wall of the casing of the electrical apparatus or to a cover (22) of the trough (20).
Circuit breaker according to any of the preceding claims, characterised in that one end (23) of the high voltage fuse (17) serves at each phase as one fixed contact of the circuit breaker.
Circuit breaker according to any of the preceding claims, characterised in that the lever arm (8) is an independent means.
Circuit breaker according to any of the preceding claims, characterised in that bellows (10) are arranged in connection with the circuit breaker, which bellows are provided with a trip pin (14) arranged to turn the shaft (6) of the circuit breaker by means of the lever arm over the dead spot of turning the shaft, when the pressure of the dielectric liquid exceeds the preset threshold value.
Circuit breaker according to any of the preceding claims, characterised in that a bimetal means is arranged in connection with the circuit breaker, the means being provided with a trip pin arranged to turn the shaft (6) of the circuit breaker by means of the lever arm over the dead spot of turning the shaft, when the temperature of the dielectric liquid exceeds the preset threshold value.
Circuit breaker according to any of the preceding claims, characterised in that a float is arranged in connection with the circuit breaker, the float being provided with a trip pin arranged to turn the shaft (6) of the circuit breaker by means of the lever arm over the dead spot of turning the shaft, when the liquid level is below the preset value.
Circuit breaker according to any of the preceding claims, characterised in that an electromechanical trigger is arranged in connection with the circuit breaker to turn the shaft (6) of the circuit breaker by means of the lever arm over the dead spot of turning the shaft.
Circuit breaker according to any of the preceding claims, characterised in that a temperature sensor, such as a capillary or a bimetal means, provided with a trigger is additionally arranged in connection with the circuit breaker, the trigger being arranged to turn the shaft of the circuit breaker by means of the lever arm over the dead spot of turning the shaft, when the temperature of the windings of the electrical apparatus exceeds the preset threshold value.
Circuit breaker according to any of the preceding claims, characterised in that the circuit breaker is provided with at least one auxiliary contact for transferring position data of the circuit breaker.
Dependencies are inferred from the claim text.