Low force low oil trip mechanism
First Claim
1. A circuit breaker for a transformer, comprising:
- a tripping apparatus that moves a movable contact relative to a stationary contact to open and close a circuit, wherein the tripping apparatus comprises a first lever arm coupled to the movable contact and a second lever arm coupled to a rod, wherein the rod is detachably coupled to the first lever arm such that when the rod is detached from the first lever arm, the first lever arm descends moving the movable contact;
fault interrupting means for causing the tripping apparatus to move the movable contact upon a fault condition in the transformer; and
low oil trip means for causing the tripping apparatus to move the movable contact when a level of dielectric fluid in a tank of the transformer is below a threshold level,wherein the low oil trip means operates independently of the fault interrupting means to open the circuit without actuating any components of the fault interrupting means.
3 Assignments
0 Petitions
Accused Products
Abstract
A circuit breaker for a transformer includes means for interrupting circuitry in the transformer upon a fault condition in the transformer (the “fault interruption means”). The circuit breaker also includes means for interrupting the circuitry when a level of dielectric fluid in a tank of the transformer is unacceptably low (the “low oil trip means”). The fault interruption means includes a magnet, metal element, and first actuator. Upon the fault condition, the magnet and metal element separate, moving the first actuator to cause the electrical circuitry to open. The low oil trip means includes a float, insulating rod, and second actuator. When the dielectric fluid level drops to an unacceptably low level, the float and insulating rod drop, moving the second actuator to cause the circuitry to open. The low oil trip means operates independently of the fault interruption means, opening the circuitry without separating the magnet and metal element.
93 Citations
18 Claims
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1. A circuit breaker for a transformer, comprising:
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a tripping apparatus that moves a movable contact relative to a stationary contact to open and close a circuit, wherein the tripping apparatus comprises a first lever arm coupled to the movable contact and a second lever arm coupled to a rod, wherein the rod is detachably coupled to the first lever arm such that when the rod is detached from the first lever arm, the first lever arm descends moving the movable contact; fault interrupting means for causing the tripping apparatus to move the movable contact upon a fault condition in the transformer; and low oil trip means for causing the tripping apparatus to move the movable contact when a level of dielectric fluid in a tank of the transformer is below a threshold level, wherein the low oil trip means operates independently of the fault interrupting means to open the circuit without actuating any components of the fault interrupting means. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A circuit breaker for a transformer, comprising:
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a stationary contact configured to be electrically coupled to a circuit of a transformer; a movable contact; a tripping apparatus that moves the movable contact relative to the stationary contact to open and close the circuit, wherein the tripping apparatus comprises a first lever arm coupled to the movable contact and a second lever arm coupled to a rod, wherein the rod is detachably coupled to the first lever arm such that when the rod is detached from the first lever arm, the first lever arm descends moving the movable contact; a fault interrupting apparatus that causes the tripping apparatus to open the circuit upon a fault condition in the transformer; and a low oil trip apparatus that causes the tripping apparatus to open the circuit when a level of dielectric fluid in a tank of the transformer is below a threshold level, wherein the low oil trip apparatus operates independently of the fault interrupting apparatus to open the circuit without actuating any components of the fault interrupting apparatus. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A circuit breaker assembly for a transformer, comprising:
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a plurality of circuit breakers, each circuit breaker comprising; a tripping apparatus that moves a movable contact relative to a stationary contact to open and close a circuit, wherein the tripping apparatus comprises a first lever arm coupled to the movable contact and a second lever arm coupled to a rod, wherein the rod is detachably coupled to the first lever arm such that when the rod is detached from the first lever arm, the first lever arm descends moving the movable contact; a fault interrupting means for causing the tripping apparatus to move the movable contact to open upon a fault condition in the transformer, and low oil trip means for causing the tripping apparatus to move the movable contact to open when a level of dielectric fluid in a tank of the transformer is below a threshold level, wherein the low oil trip means operates independently of the fault interrupting means to open the circuit without actuating any components of the fault interrupting means; and a linkage bar coupled to each of the circuit breakers, the linkage bar rotating in response to the fault interrupting means of one of the circuit breakers causing the circuit associated with the one of the circuit breakers to open, the rotating of the linkage bar causing the fault interrupting means of each other circuit breaker to open the circuit associated with the other circuit breaker. - View Dependent Claims (16, 17)
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18. A method for protecting a circuit of a transformer, comprising the steps of:
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determining whether a fault condition exists in a transformer; in response to determining that a fault condition exists in the transformer, releasing a magnetic coupling to cause a tripping apparatus to open the circuit in the transformer; determining whether a level of dielectric fluid in a tank of the transformer is below a threshold level; and in response to determining that the level of dielectric fluid is below the threshold level, causing the tripping apparatus to open the circuit in the transformer without releasing the magnetic coupling, wherein the tripping apparatus moves a movable contact relative to a stationary contact to open and close the circuit, wherein the tripping apparatus comprises a first lever arm coupled to the movable contact and a second lever arm coupled to a rod, wherein the rod is detachably coupled to the first lever arm such that when the rod is detached from the first lever arm, the first lever arm descends moving the movable contact.
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Specification