Electronically controlled fusible switching disconnect modules and devices

Patent metadata

Field	Value
Publication number	US-11217413-B2
Application number	US-201113008940-A
Country	US
Kind code	B2
Filing date	Jan 19, 2011
Priority date	Sep 13, 2004
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

A fusible switch disconnect device includes a housing adapted to receive at least one fuse therein, and a switchable contact for connecting the fuse to circuitry. A tripping mechanism and control circuitry are provided to move the switchable contact to an open position in response to a predetermined electrical condition.

First claim

What is claimed is:

1. A circuit protection device comprising:
a fusible switch disconnect assembly, the fusible switch disconnect assembly comprising:
a switch housing adapted to accept at least a portion of a compatible time delay fuse with plug-in connection, the compatible time delay fuse including first and second terminal blade elements and a fusible element electrically connected therebetween, the fusible element defining a circuit path having a predetermined current rating and that is configured to permanently open according to a continuous time-current curve;
line side and load side terminals in the switch housing and electrically connecting to the respective first and second terminal blade elements when the at least the portion of the compatible time delay fuse is accepted with plug-in connection in the switch housing;
a pair of stationary switch contacts and a pair of movable switch contacts in the switch housing, the pair of stationary switch contacts provided between the line side terminal and the first terminal blade element of the compatible time delay fuse, the pair of movable switch contacts selectively positionable in an open position and a closed position to respectively disconnect or connect an electrical connection through the circuit path of the fusible element of the compatible time delay fuse;
a mechanism operable to cause the pair of movable switch contacts to automatically move to the open position, wherein the mechanism comprises an electromagnetic coil and a linkage engageable by the electromagnetic coil when the electromagnetic coil is energized;
a detecting element configured to detect an actual electrical current flow through the circuit path of the fusible element; and
a controller responsive to the detected actual electrical current flow and in communication with the electromagnetic coil, the controller configured to respond to a detected longer duration overcurrent event where the detected actual electrical current flow through the current path of the fusible element is above the predetermined current rating for a period of time without causing the fusible element to open while the pair of movable switch contacts are in the closed position by:
comparing an elapsed duration of the detected actual electrical current flow that is above the predetermined current rating in the longer duration overcurrent event with a corresponding portion of the continuous time-current curve of the compatible time delay fuse that is accepted with plug-in connection in the switch housing; and
when a deviation between the compared elapsed duration of the detected actual electrical current flow that is above the predetermined current rating and the corresponding portion of the continuous time-current curve exceeds a predetermined threshold in the longer duration overcurrent event, proactively energizing the electromagnetic coil to move the pair of movable switch contacts to the open position, thereby avoiding a permanent opening of the fusible element in the compatible time delay fuse that is accepted with plug-in connection in the switch housing, and whereby the fusible switch disconnect assembly is resettable and avoids a need to replace the compatible time delay fuse because of the detected longer duration overcurrent event.

2. The circuit protection device of claim 1 , wherein the fusible switch disconnect assembly further comprises a first circuit board and a second circuit board, wherein the controller is provided on the first circuit board and wherein the second circuit board supplies power to the first circuit board.

3. The circuit protection device of claim 2 , wherein the second circuit board is connected to one of the line side and load side terminals and receives power therefrom.

4. The circuit protection device of claim 3 , wherein the second circuit board is configured to receive AC power from one of the line side and load side terminals and supply DC power to the first circuit board.

5. The circuit protection device of claim 4 , wherein the second circuit board is configured to step down the power supply from one of the line side and load side terminals and supply the stepped down power to the first circuit board.

6. The circuit protection device of claim 1 , wherein the electromagnetic coil comprises a solenoid.

7. The circuit protection device of claim 1 , wherein the fusible switch disconnect assembly further comprises an indicator responsive to the controller to indicate the detected longer duration overcurrent event.

8. The circuit protection device of claim 7 , wherein the indicator is a light emitting diode.

9. The circuit protection device of claim 7 , wherein the indicator is operable in at least two distinct modes.

10. The circuit protection device of claim 9 , wherein the at least two distinct modes includes a continuous indication mode and an intermittent indication mode.

11. The circuit protection device of claim 1 , wherein the fusible switch disconnect assembly further comprises a neutral terminal, the controller electrically connected to the neutral terminal.

12. The circuit protection device of claim 11 , wherein the fusible switch disconnect assembly further comprises an overvoltage detecting element, the overvoltage detecting element connected between one of the line side and load side terminals and the neutral terminal.

13. The circuit protection device of claim 1 , wherein the detecting element is a Hall Effect sensor, a current transformer, or a shunt.

14. The circuit protection device of claim 1 , wherein the detecting element comprises a resistive shunt integrally provided in a conductive terminal element in the switch housing.

15. The circuit protection device of claim 1 , wherein the pair of movable switch contacts are spring biased to the open position.

16. The circuit protection device of claim 1 , wherein the compatible time delay fuse comprises a rectangular fuse module, the terminal blade elements projecting from a common side of the rectangular fuse module and being spaced apart from one another.

17. The circuit protection device of claim 1 , wherein the electromagnetic coil comprises a cylinder extendable and retractable along a first axis, and the pair of movable switch contacts being displaced along a second axis perpendicular to the first axis.

18. The circuit protection device of claim 1 , wherein the compatible time delay fuse is a Class J fuse.

19. The circuit protection device of claim 1 , wherein the compatible time delay fuse has an amperage rating of 1-100 A.

20. The circuit protection device of claim 1 , wherein the predetermined threshold is a percentage of the time indicated in the continuous time-current curve at a current magnitude equal to the actual electrical current flow.

21. The circuit protection device of claim 1 , wherein the predetermined threshold exceeds the time indicated in the continuous time-current curve at a current magnitude equal to the actual electrical current flow.

22. A circuit protection device comprising:
a fusible switch disconnect assembly comprising:
a disconnect housing adapted to receive and engage at least a portion of a removable time delay overcurrent protection fuse, the removable time delay overcurrent protection fuse including first and second terminal elements and a fusible element electrically connected therebetween, the fusible element defining a circuit path having a predetermined current rating and being configured to permanently open the circuit path in response to a p

Assignees

• Darr Matthew Rain
• Kamath Hundi Panduranga
• Eaton Intelligent Power Ltd

Inventors

• Darr Matthew Rain
• Kamath Hundi Panduranga

Classifications

• H01H1/20 Primary

  Bridging contacts {(for circuit breakers H01H73/045)} · CPC title

• H01H83/12

  operated by voltage falling below a predetermined value, e.g. for no-volt protection · CPC title

• H01H9/104

  with interlocking mechanism between switch and fuse · CPC title

• H01H71/125

  characterised by sensing elements, e.g. current transformers (for differential protection H01H83/144) · CPC title

• H01H71/04

  Means for indicating condition of the switching device {(by means of an auxiliary contact H01H71/46)} · CPC title