Claims
- 1. A method for reconfiguring a molded case circuit breaker over a broad range of current ratings by utilizing interchangeable members, with the circuit braker having a molded housing with removable cover, an operating mechanism having a movable contact in the housing and coupled to a line terminal and an intermediate latching mechanism, and a load terminal including a load bus member mounted in the housing, with the load terminal coupled to the movable contact member, the method comprising the steps of:installing a trip unit in the housing; with the trip unit having a magnetic short circuit release and a thermal overload release with interchangeable bi-metal members; and coupling the trip unit to the moveable contact and load terminal with the trip unit in selective operative contact with the intermediate latching mechanism.
- 2. The method of claim 1, including the step of nesting an inner yoke between spaced apart perpheral flanges of an outer yoke in the magnetic short circuit release.
- 3. The method of claim 1, including the step of attaching an additional magnetic shield to an integral shield of the outer yoke in the magnetic short circuit release.
- 4. The method of claim 1, including the step of installing an interchangeable bi-metal member in the thermal overload release selected from a group consisting of a wide bi-metal conductor and a narrow bi-metal conductor.
- 5. The method of claim 1, wherein the load bus member is a copper alloy having a chemical composition of CDA #19400 with an electrical conductivity of not more than 40% IACS.
- 6. A circuit breaker comprising:a housing including a base; a means for connecting a load to the breaker, mounted in the housing: a means for connecting an electrical line to the breaker, mounted in the housing; a stationary contact electrically coupled to the means for connecting an electrical line; a moveable contact coupled to a means for operating mounted in the housing and having a pivoting member moveable between an ON position and OFF position, and a TRIPPED position, with the pivoting member coupled to the moveable contact and with the means for operating coupled to an intermediate means for latching the means for operating; and a means for tripping coupled to the moveable contact and the means for connecting a load with the means for tripping in selective operative contact with the intermediate means for latching; wherein the means for tripping includes a means for releasing under a short circuit condition and a means for releasing under an overload condition, wherein the means for releasing under a short circuit condition comprises an outer yoke with a magnetic shield and the means for releasing under an overload condition includes an interchangeable bi-metal member.
- 7. The circuit breaker of claim 6, wherein the outer yoke is provided with spaced apart peripheral flanges and including an inner yoke nested between the flanges of the outer yoke.
- 8. The circuit breaker of claim 6, including a second magnetic shield attached to the outer yoke.
- 9. The circuit breaker of claim 6, wherein the interchangeable bi-metal member is selected from a group consisting of a wide bi-metal conductor and a narrow bi-metal conductor.
Parent Case Info
This is a division of Application Ser. No. 06/434,233 filed Nov. 5, 1999, now Pat. No. 6,181,226, issued Jan. 30, 2001, and titled BI-METAL TRIP UNIT FOR A MOLDED CASE CIRCUIT BREAKER.
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