Circuit breaker system with ASM instantaneous overcurrent indication

• US 6,504,694 B1
• Filed: 11/05/1999
• Issued: 01/07/2003
• Est. Priority Date: 11/05/1999
• Status: Expired due to Term

• Current Assignee: Siemens Industry Incorporated (Siemens AG)
• Original Assignee: Siemens Energy & Automation Incorporated (Siemens AG)
• Inventors: Bilac, Mario, Dollar, Charles Randall II
• Primary Examiner(s): Jackson, Stephen W.
• Assistant Examiner(s): KITOV, ZEEV V
• Application Number:
  US09/434,631
• Time in Patent Office: 1,159 Days
• Field of Search: 361/93.2, 361/96, 361/64, 361/72, 361/50
• US Class Current: 361/93.2
• CPC Class Codes: H02H 3/04 with warning or supervision in addition to disconnection, e.g. for indicating that protective apparatus has functioned watching of pilot wires H02H1/0084; protection of protective arrangements H02H7/008; indication of the state of electronic switches H03K17/18

Abstract

A circuit breaker system (100) providing application specific module (ASM) instantaneous overcurrent indication is disclosed herein (FIG. 5). A trip unit (110) included in the circuit breaker system (100) is powered by an external power supply unit (134) in the ASM (104). The circuit breaker system (100) includes transmitting an indication signal (130) from the trip unit (110) to the ASM (104) in response to an overcurrent condition. The indication signal (130) triggers a first controller (130) included in the ASM (104), the first controller (130) configured to cause the external power supply unit (134) to maintain power to the trip unit (110) for a first length for time sufficient to communicate a data corresponding to the overcurrent condition to the ASM (104). The output of the first controller (130) triggers a second controller (132) included in the ASM (104), the second controller (132) configured to cause the external power supply unit (134) to reset the trip unit (110) in readiness to respond to the next overcurrent condition. The data received by the ASM (104) may be processed to form a trip and overcurrent data set for display in a display unit (112).

Claims

1. A system for sensing and indicating an overcurrent condition in an electrical circuitry, comprising:

a trip unit configured to sense the overcurrent condition;

a module coupled to the trip unit and configured to selectively control power to the trip unit in response to an indication signal transmitted from the trip unit, wherein selectively controlling the power to the trip unit permits communication of a data corresponding to the overcurrent condition and permits configuring the trip unit to sense a subsequent overcurrent condition, wherein the module includes a first controller configured to continue power to the trip unit for a first length of time after the overcurrent condition has been sensed by the trip unit; and

a second controller configured to reset the trip unit after the data has been communicated, wherein the second controller is a monostable multivibrator and the trip unit is reset by toggling the power to the trip unit “

off”

for a second length of time and then “

on.”

2. The system of claim 1, wherein the second length of time is a length of time sufficient for the trip unit to discharge.

3. The system of claim 1, wherein the module includes an external power supply for the trip unit, the first controller receiving the indication signal and outputting a delay signal to the second controller and the second controller outputting a reset signal to the external power supply.

4. The system of claim 1, wherein the trip unit includes a processor and an electromechanical interface unit, the processor configured to transmit the indication signal to the module and to transmit a trip signal to the electromechanical interface unit to actuate tripping of the electrical circuitry.

5. The system of claim 4, wherein the indication signal is processed by at least one signal buffer and electro-static protection unit after output from the processor.

6. The system of claim 4, wherein the module includes a microcontroller configured to perform at least one of communicate with the processor, process the data from the trip unit into a trip and overcurrent data set, store the trip and overcurrent data set, and communicate the trip and overcurrent data set to a display unit.

7. The system of claim 6, wherein the trip and overcurrent data set includes at least one of an overload trip occurrence indication, a short time trip occurrence indication, a ground fault trip occurrence indication, an instantaneous trip occurrence indication, a count of the overload trip occurrences, a count of the short time trip occurrences, a count of the ground fault trip occurrences, a count of the instantaneous trip occurrences, a count of an under load switching operations, a sum of I²T values, and a time stamp of each trip occurrence.

8. A method of providing an overcurrent protection and indication for an electrical circuitry, comprising:

(a) sensing an overcurrent condition with a trip unit;

(b) initiating a trip to protect the electrical circuitry in response to the overcurrent condition;

(c) transmitting an indication signal to a module coupled to the trip unit;

(d) controlling a power to the trip unit by the module; and

(e) communicating a data corresponding to the overcurrent condition to the module;

wherein step (d) of controlling the power includes resetting the trip unit after step (e) of communicating the data by toggling the power to the trip unit “

off”

for a second length of time and then “

on.”

9. The method of claim 8, wherein the second length of time is a length of time sufficient of the trip unit to discharge.

10. The method of claim 8, wherein steps (a) to (e) are repeated a plurality of times as desired to provide repeated overcurrent protection and indication.

11. The method of claim 8, further comprising at least one of:

(f) processing the data into a trip and overcurrent data set by a microcontroller included in the module;

(g) storing the trip and overcurrent data set in the module;

(h) communicating the trip and overcurrent data set to a display unit; and

(i) displaying the trip and overcurrent data set on the display unit.

12. The method of claim 11, wherein step (i) of displaying includes at least one of displaying an overload trip occurrence indication, a short time trip occurrence indication, a ground fault trip occurrence indication, an instantaneous trip occurrence indication, a count of the overload trip occurrences, a count of the short time trip occurrences, a count of the ground fault trip occurrences, a count of the instantaneous trip occurrences, a count of an under load switching operations, a sum of I²T values, and a time stamp of each trip occurrence.

13. A system for sensing and indicating an overcurrent condition in an electrical circuitry, comprising:

means for sensing the overcurrent condition in the electrical circuitry;

means for communicating an indication signal and a data corresponding to the overcurrent condition, the means for sensing coupled to the means for communicating;

means for selectively controlling a power to the means for sensing and the means for communicating, the means for communicating coupled to the means for selectively controlling; and

means for initiating a trip of the electrical circuitry in response to the overcurrent condition, the means for initiating coupled to the means for sensing and the means for communicating,

wherein the means for selectively controlling includes a first monostable multivibrator coupled to a second monostable multivibrator and the second monostable multivibrator coupled to an external power supply for the means for communicating.

14. The system of claim 13, wherein the means for sensing includes a current transformer and the means for communicating includes a processor.

15. The system of claim 13, wherein the first monostable multivibrator receives the indication signal and outputs a delay signal, the first monostable multivibrator configured to cause the external power supply to maintain power to the means for communicating for a first length of time after the trip of the electrical circuitry.

16. The system of claim 15, wherein the first length of time is a length of time sufficient for the means for communicating to communicate the data to the means for selectively controlling.

17. The system of claim 15, wherein the second monostable multivibrator receives the delay signal and outputs a reset signal, the second monostable multivibrator configured to cause the external power supply to reset the means for communicating and the means for sensing by toggling the power “

off”

for a second length of time and then “

on.”

18. The system of claim 17, wherein the second length of time starts after the end of the first length of time and is a length of time sufficient for the means to sense to discharge.

19. The system of claim 13, further comprising means for signal buffering and protecting the indication signal in at least one of the means for communicating and the means for selectively controlling.

20. The system of claim 13, wherein the means for selectively controlling includes a microcontroller, wherein the microcontroller is configured to perform at least one of communicate with the means for communicating, process the data into a trip and overcurrent data set, store the trip and overcurrent data set, and communicate the trip and overcurrent data set to a means for displaying.

21. The system of claim 20, wherein the trip and overcurrent data set includes as least one of an overload trip occurrence indication, a short time trip occurrence indication, a ground fault trip occurrence indication, an instantaneous trip occurrence indication, a count of the overload trip occurrences, a count of the short time trip occurrences, a count of the ground fault trip occurrences, a count of the instantaneous trip occurrences, a count of an under load switching operations, a sum of I²T values, and a time stamp of each trip occurrence.