Circuit breaker

Patent metadata

Field	Value
Publication number	US-10218167-B2
Application number	US-201615140598-A
Country	US
Kind code	B2
Filing date	Apr 28, 2016
Priority date	Apr 30, 2015
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

A circuit breaker includes a tripping unit for interrupting an electrical circuit, and at least one current sensor for determining the electrical current flowing through the circuit breaker, connected to a control unit and configured such that the determined current is compared with current/period limit values. If a current/period limit value is exceeded, the tripping unit interrupts the electrical circuit. The current/period limit values include an adjustable first current limit value, present for a first period for an interruption; an adjustable second period, during which a second current limit value must be present to effect an interruption; and a range between the first current limit value and the second current limit value, the period decreasing with increasing current limit values in order to effect an interruption. The second current limit value can be adjusted at the circuit breaker.

First claim

What is claimed is:

1. A circuit breaker for an electrical circuit, comprising:
a tripping unit to interrupt the electrical circuit; and
at least one current sensor to determine electrical current flowing through the circuit breaker, the tripping unit and at least one current sensor being connected to a control unit and being configured such that a determined current is comparable with current/period limit values and, upon a current/period limit value being exceeded, the tripping unit is configured to interrupt the electrical circuit, the current/period limit values including:
an adjustable first current limit value, necessary to be present for a first period to effect an interruption,
an adjustable second period, during which a second current limit value is necessary to be present to effect an interruption,
a range between the first current limit value during the first period and the second current limit value during the second period, the range relatively decreasing with relatively increasing current limit values in order to effect an interruption, wherein the second current limit value is adjustable at the circuit breaker,

wherein the circuit breaker includes a fixed rated current and wherein the second current limit value is adjustable as a multiple of the rated current,
wherein an adjustable third current limit value, relatively less than or equal to the rated current, which when exceeded, causes an interruption with a relatively long time delay, the period relatively decreasing with relatively increasing current limit values, to be affected by way of a current/period limit value characteristic curve which includes an inverse power function including a supporting point:
a first multiple of the third current limit value during a third period, and wherein a fourth current limit value is provided which, when exceeded, causes the circuit breaker to interrupt the electrical circuit without a delay.

2. The circuit breaker of claim 1 , wherein the range between the first current limit value during the first period and the second current limit value during the second period includes a current/period limit value characteristic curve involving part of an inverse quadratic function.

3. The circuit breaker of claim 1 , wherein the inverse power function is a fourth-power inverse power function.

4. The circuit breaker of claim 1 , wherein the first multiple of the third current limit value is 6 times the third current limit value.

5. The circuit breaker of claim 1 , wherein the second current limit value is adjustable as a multiple of the third current limit value.

6. The circuit breaker of claim 1 , wherein the second current limit value is adjustable in a range of 6 times to 12 times the third current limit value.

7. The circuit breaker of claim 1 , wherein the first current limit value is adjustable as a multiple of the rated current or of the third current limit value.

8. The circuit breaker of claim 1 , wherein the second current limit value is adjustable as a multiple of the first current limit value.

9. The circuit breaker of claim 1 , wherein the second period is relatively shorter than or equal to the first period.

10. The circuit breaker of claim 1 , wherein the third current limit value is relatively less than the first current limit value.

11. The circuit breaker of claim 1 , wherein the circuit breaker is an air circuit breaker.

12. The circuit breaker of claim 1 , wherein the circuit breaker is a molded case circuit breaker.

13. The circuit breaker of claim 1 , wherein an additional current limit value is provided which, when exceeded, causes the circuit breaker to interrupt the electrical circuit without a delay.

14. A circuit breaker for an electrical circuit, comprising:
a tripping unit to interrupt the electrical circuit; and
at least one current sensor to determine electrical current flowing through the circuit breaker, the tripping unit and at least one current sensor being connected to a control unit and being configured such that a determined current is comparable with current/period limit values and, upon a current/period limit value being exceeded, the tripping unit is configured to interrupt the electrical circuit, the current/period limit values including:
an adjustable first current limit value, necessary to be present for a first period to effect an interruption,
an adjustable second period, during which a second current limit value is necessary to be present to effect an interruption,
a range between the first current limit value during the first period and the second current limit value during the second period, the range relatively decreasing with relatively increasing current limit values in order to effect an interruption, wherein the second current limit value is adjustable at the circuit breaker,

wherein the circuit breaker includes a fixed rated current and wherein the second current limit value is adjustable as a multiple of the rated current, and
wherein an additional current limit value is provided which, when exceeded, causes the circuit breaker to interrupt the electrical circuit without a delay.

15. The circuit breaker of claim 14 , wherein an adjustable third current limit value, relatively less than or equal to the rated current, which when exceeded, causes an interruption with a long time delay, the period relatively decreasing with relatively increasing current limit values, to be affected by way of a current/period limit value characteristic curve which includes an inverse power function with the supporting point:
a first multiple of the third current limit value during a third period.

16. The circuit breaker of claim 14 , wherein the circuit breaker is an air circuit breaker.

17. The circuit breaker of claim 14 , wherein the circuit breaker is a molded case circuit breaker.

18. The circuit breaker of claim 14 , wherein the range between the first current limit value during the first period and the second current limit value during the second period includes a current/period limit value characteristic curve involving part of an inverse quadratic function.

19. The circuit breaker of claim 18 , wherein the circuit breaker is an air circuit breaker.

20. The circuit breaker of claim 18 , wherein the circuit breaker is a molded case circuit breaker.

21. The circuit breaker of claim 15 , wherein the inverse power function is a fourth-power inverse power function.

22. The circuit breaker of claim 21 , wherein the first multiple of the third current limit value is 6 times the third current limit value.

23. The circuit breaker of claim 21 , wherein the second current limit value is adjustable as a multiple of the third current limit value.

24. The circuit breaker of claim 21 , wherein the second current limit value is adjustable in a range of 6 times to 12 times the third current limit value.

25. The circuit breaker of claim 14 , wherein an additional current limit value is provided which, when exceeded, causes the circuit breaker to interrupt the electrical circuit without a delay.

26. The circuit breaker of claim 14 , wherein the first current limit value is adjustable as a multiple of the rated current or of the third current limit value.

27. The circuit breaker of claim 14 , wherein the second current limit value is adjustable as a multiple of the first current limit value.

28. The circuit breaker of claim 14

Assignees

• Siemens Ag

Inventors

• Franke Henry
• Fruth Wolfgang
• Haebel Stefan
• HUENTEMEIER Rainer

Classifications

• H02H7/30

  Staggered disconnection · CPC title

• H01H9/54

  Circuit arrangements not adapted to a particular application of the switching device and for which no provision exists elsewhere · CPC title

• H02H3/0935 Primary

  the timing being determined by numerical means · CPC title

• H02H3/006

  Calibration or setting of parameters · CPC title

• H01H71/00 Primary

  Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00 · CPC title