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AssigneeSiemens Aktiengesellschaft
InventorsRodrigo CHORA DE LA GARZA, Ivan Alejandro GARCIA TOVAR, Francisco Javier HURTADO MEZA, Dariel TELLEZ TREVINO
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A bimetal unit for a circuit breaker is disclosed, the bimetal unit including a bimetal element for releasing a trip mechanism of the circuit breaker. In an embodiment, the bimetal element is surrounded, in particular coaxially surrounded, by a ferrous ring and a copper coil wound around the ferrous ring. The ferrous ring and copper coil provide a compensation device which produces additional heat and, as a result, stronger bending to the bimetal element when a current flows through the same bimetal element. An embodiment of the invention is useful to employ bimetal element adapted for higher-rated current in a circuit breaker of lower-rated current as bimetal element exhibits similar bending behavior as in higher-rated circuit breaker. This enhances calibration and reduces manufacturing costs. A trip unit, a circuit breaker, a series of circuit breakers, and a method for calibrating a circuit breaker employing the bimetal unit, are also disclosed.
A bimetal unit for a circuit breaker, comprising:
A series of circuit breakers, each including a directly heated bimetal element, the series of circuit breakers including a first type of circuit breaker designed for a first rated current and a second type of circuit breaker designed for a second rated current being relatively higher than the first rated current, wherein the first type of circuit breaker and the second type of circuit breaker share a common type of bimetal element, wherein in the first type of circuit breaker, the bimetal element is surrounded by a ferrous ring and a copper coil, the copper coil being wound around the ferrous ring, and wherein in the second type of circuit breaker, the bimetal element is not surrounded by a ferrous ring and a wound-around copper coil, or is surrounded by a ferrous ring and a copper coil wound around the ferrous ring having at least one of a magnetic capacity and induction capacity relatively lower than in the first type of circuit breaker.
A method for thermally calibrating a circuit breaker having a bimetal unit including a directly heated bimetal element, the method comprising:
The method of claim 12, wherein the calibration time is 55 seconds or more.
Dependencies are inferred from the claim text.