Westinghouse Air Circuit Breakers 600V: 1945 – The Present
Cutler Hammer Air Circuit Breaker
Westinghouse air circuit breakers were among the first original manufactured air circuit breakers made. Westinghouse circuit breakers, like other manufacturers began production on the first “resetable fuse”, after 1945. These early circuit breakers were large mounted on heavy slate and featured dashpot / “sucker disk” trip units. Westinghouse produced both draw-out circuit breakers and bolt-in circuit breakers. 600 volt air circuit breakers were also sold as electrically operated or manually operated.
Westinghouse 600 volt circuit breakers produced in 1945 were called: DK- 25, DA-50, DA-75, and DA-100.Frame sizes ranged from 600 amp to 6000 amp. In approximately 1955, Westinghouse changed its entire circuit breaker line and began producing DB air circuit breakers. Westinghouse DB air circuit breakers were produced in similar frames sizes, as were the Westinghouse DA circuit breakers. These models were: DB-25- 600 amp frame, DB-50- 1600 amp frame, DB-75- 3000 amp frame, and DB-100, 4000 amp frame. These Westinghouse DB circuit breakers had two generations that spanned a total of 70 years.
Westinghouse produced DB single position circuit breakers and then improved on the design and manufactured DB 3 position circuit breakers. Westinghouse 3 position, DB circuit breakers, featured a “test” position where the breaker could be racked off of the back stabs, and still be in the cell. This allowed a user to test the breakers close & trip functions, while not engaging a load.
In approximately 1975, Westinghouse introduced the DS circuit breaker line and DS switchgear, which became the basic platform for their breakers still produced today, the Cutler Hammer DSII circuit breakers. Earlier DS breaker models were as follows: DS-206-800 amp frame, DS-416-1600 amp frame, DS-632-3200 amp frame, DS-840-4000 amp frame. Also a 2000 amp frame DS-420, and fused model, DSL-206, DSL-416, DSL-632, and DSL-840.
The Westinghouse circuit breaker line was purchased by Cutler Hammer. DS circuit breakers are still made but now owned by the Eaton / Cutler Hammer group. A new trip unit was added that featured among other things, the ability to communicate. Basic models were 800 amp frame, DSII-308, DSII-508, DSII-608, 1600 amp frame size, DSII-516, DSII-616, 3200 amp frame size, DSII-632, and 4000 amp frame size, DSII-840. Cutler Hammer now also provides the Magnum line of breakers.