Apparatus comprising circuit breaker with adjunct sensor unit
View Patent ↗A self-contained current sensor unit is integrated with a standard circuit breaker as an attachment to the circuit breaker that requires minimal modification of the circuit breaker and that becomes an extension of the case of the circuit breaker. The current sensor unit includes a magnetic structure with a programmable Hall Effect device and may include a power supply, a Hall Effect voltage regulator, and an output signal conditioner.
1. Apparatus comprising:
a circuit breaker including a switching mechanism in a box-shape case having opposite ends; and
a current sensor unit including a current sensor self-contained in an additional box-shape case,
wherein the case of the current sensor unit is connected with one end of the case of the circuit breaker,
wherein a flexible current carrying conductor of the circuit breaker is routed from the case of the circuit breaker into the additional case so as to pass through the current sensor unit,
wherein the current sensor unit has an integral annular magnetic core located entirely in the additional case and mounted to a circuit board in the additional case,
wherein the flexible conductor is wound about a portion of the magnetic core,
wherein the circuit breaker has an overcurrent-responsive tripping device connected in a main current carrying circuit extending between terminals external to a side of the circuit breaker case, and
wherein the current sensor unit includes electronic circuitry with an output terminal that is devoid of connection to the tripping device and that provides an output signal related to the current carried by the flexible current carrying conductor.
2. Apparatus according to claim 1 , wherein the magnetic core comprises a torodial core through which the conductor passes.
3. Apparatus according to claim 1 , wherein the magnetic core has a gap containing a Hall Effect device.
4. Apparatus according to claim 3 , wherein the Hall Effect device is programmable and has a programming connector.
5. Apparatus according to claim 3 , wherein the current sensor unit includes at least one of a Hall Effect regulator, a power supply, and a Hall Effect output signal conditioner.
6. Apparatus according to claim 3 , wherein the current sensor unit has a Hall Effect output signal conditioner including a level shifter and at least one gain stage.
7. Apparatus according to claim 3 , wherein the current sensor unit has a Hall Effect output signal conditioner including a level shifter, a primary gain stage, a secondary gain stage, and an output stage.
8. Apparatus according to claim 1 , wherein the current sensor unit communicates with the circuit breaker through opposed openings in the respective cases.
9. Apparatus according to claim 1 , wherein each case is comprised of box portions connected together by fasteners.
10. Apparatus according to claim 1 , wherein the case of the current sensor unit comprises two box portions that are hinged to one another.
11. An apparatus according to claim 1 , wherein the case of the current sensor unit and the case of the circuit breaker are formed as two integrally molded box portions that are connected by fasteners.
12. An Apparatus according to claim 1 , wherein the magnetic core is mounted in a support integral with a case portion of the current sensor unit.
13. An apparatus according to claim 12 , wherein the magnetic core comprises a rectangular annulus with a leg extending through a sleeve on which the current carrying conductor is wound.
14. An apparatus according to claim 1 , wherein each box-shape case is generally rectangular.