Circuit breaker with fast trip unit
AssigneeWestinghouse Electric Corp.
InventorsStephen A. Mrenna, Kurt A. Grunert, Jonathan Weiss, Vijay K. Garg
Life of this patent
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Abstract
A circuit breaker structure having a faster trip unit characterized by a circuit breaker operator and a trip unit comprising a coil, a core, and an armature, a flux concentrating plate spaced from and on the side of the armature opposite the core and for concentrating the magnetic field between the core and the armature, and a hold-back bracket having extending from and retaining the armature in a spaced position from the core so as to cause the magnetic field lines to flow through the bracket and the armature.
Claims10
A circuit breaker structure having a faster trip action, comprising:
- a circuit breaker mechanism having separable contacts and having a releasable member movable to an unlatched position from a latched position to effect opening of the contacts;
- a latch lever movable between latched and unlatched positions of the releasable member and being biased in the latched position;
- a trip bar movable to unlatch the latch lever and being biased in the latched position;
- a trip unit comprising a stationary magnetic structure for each conductor of the distribution system and including a coil and first magnetic core assembly and an armature;
- lever means associated with each stationary magnetic structure for moving the trip bar to the unlatched position;
- the lever means comprising the armature and movable toward the core in response to abnormal currents in at least one of the conductors;
- and
- a flux concentrating magnetic plate separated from the magnetic core assembly and spaced from and on the side of the armature opposite the core and for concentrating a magnetic field in an ambient space between the core and the armature.
A circuit breaker structure having a faster trip action, comprising:
- a circuit breaker mechanism having separable contacts and having a releasable member movable to an unlatched position from a latched position to effect opening of the contacts;
- a latch lever movable between latched and unlatched positions of the releasable member and being biased in the latched position;
- a trip bar movable to unlatch the latch lever and being biased in the latched position;
- a trip unit comprising a stationary magnetic structure for each conductor of the distribution system and including a coil and first core assembly and an armature;
- lever means associated with each stationary magnetic structure for moving the trip bar to the unlatched position;
- the lever means comprising the armature and movable toward the core in response to abnormal currents in at least one of the conductors;
- a flux concentrating plate spaced from and on the side of the armature opposite the core and for concentrating a magnetic field in an ambient space between the core and the armature;
- the flux concentrating plate including calibration means for moving the plate to and from the armature so as to adjust the magnetic field assembly;
- and
- the flux concentrating plate being a substantially U-shaped member having an intermediate portion and third U-legs slidably mounted on respective first U-legs of the core;
- and
- set screw means for adjusting the spacing between the intermediate portion and the core and the armature being disposed between the third U-legs and in contact with the member.
Dependencies are inferred from the claim text.