Fusible switching disconnect modules and devices with in-line current detection

Patent metadata

Field	Value
Publication number	US-11355299-B2
Application number	US-201615251479-A
Country	US
Kind code	B2
Filing date	Aug 30, 2016
Priority date	Jan 19, 2011
Publication date	Jun 7, 2022
Grant date	Jun 7, 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 current detecting element, a tripping mechanism, and control circuitry are provided to move the switchable contact to an open position in response to predetermined electrical current conditions in the device.

First claim

What is claimed is:

1. A fusible switch disconnect device comprising:
a disconnect housing adapted to receive and engage at least a portion of a removable overcurrent protection fuse module, wherein the removable overcurrent protection fuse module includes:
a fuse housing,
first and second terminal elements, and
a fusible element electrically connected between the first and second terminal elements, the fusible element defining a circuit path configured to operate according to a predetermined continuous time-current curve representing time-current conditions that the fusible element can actually withstand before permanently opening;

line and load side fuse clips in the disconnect housing and respectively receiving the first and second terminal elements of the removable overcurrent protection fuse module;
line and load side terminals in the disconnect housing and electrically connecting to the respective line and load side fuse clips;
dual switch contacts in the disconnect housing, the dual switch contacts provided between the line side terminal and the line side fuse clip, the dual switch contacts selectively positionable in an open position or a closed position to respectively disconnect or connect an electrical connection between the line side terminal and the line side fuse clip and through the circuit path of the fusible element;
an in-line current detecting element detecting in real-time a longer duration overcurrent event at a location upstream from the fusible element when the dual switch contacts are in the closed position and when the removable overcurrent protection fuse module is received and engaged in the disconnect housing with the fusible element intact and conducting current in the detected longer duration overcurrent event;
circuitry in communication with the in-line current detecting element, the circuitry configured to, based on an input from the in-line current detecting element and in real time comparison to the predetermined continuous time-current curve of the fusible element in the removable overcurrent protection fuse module that is received and engaged in the disconnect housing, assess whether or not the fusible element is expected to withstand the detected longer duration overcurrent event in order to prevent the fusible element from permanently opening; and
wherein the fuse housing of the removable overcurrent protection fuse module projects from the disconnect housing such that it is open and accessible from the exterior of the disconnect housing for removal from the disconnect housing when the first and second terminal elements of the removable overcurrent protection fuse module are connected to the line and load side fuse clips, whereby an open circuit is established between the line and load side terminals when the removable overcurrent protection fuse module is removed from the line and load side fuse clips.

2. The fusible switch disconnect device of claim 1 , further comprising a trip mechanism operable in response to the circuitry to automatically cause the dual switch contacts to move from the closed position to the open position when the circuitry assesses that the fusible element is not expected to withstand the detected real-time current conditions in the longer duration overcurrent event.

3. The fusible switch disconnect device of claim 2 , wherein the trip mechanism includes a solenoid.

4. The fusible switch disconnect device of claim 1 , wherein the line side terminal includes an end configured for connection to external circuitry, and wherein the in-line current detecting element is located between the end and the removable overcurrent protection fuse module.

5. The fusible switch disconnect device of claim 4 , wherein the in-line current detecting element is a resistive shunt.

6. The fusible switch disconnect device of claim 4 , wherein the in-line current detecting element is welded to the line side terminal.

7. The fusible switch disconnect device of claim 4 , wherein the in-line current detecting element is integrally provided on the line side terminal.

8. The fusible switch disconnect device of claim 1 , wherein the line side terminal includes a first stationary switch contact, and wherein the line side fuse clip includes a second stationary switch contact spaced from the first stationary switch contact inside the disconnect housing.

9. The fusible switch disconnect device of claim 1 , wherein the removable overcurrent protection fuse module comprises a rectangular fuse module having plug-in terminal blades.

10. The fusible switch disconnect device of claim 1 , further comprising a local state indicator operable to visually display an assessed magnitude-based and time-based current condition while the dual switch contacts remain in the closed position.

11. The fusible switch disconnect device of claim 10 , wherein the local state indicator comprises a light emitting diode.

12. The fusible switch disconnect device of claim 10 , wherein the visual display comprises intermittent illumination of the light emitting diode.

13. A fusible switch disconnect device comprising:
a housing defining a first side, a second side opposing the first side and a receptacle adapted to directly receive and engage at least a portion of a removable fuse, the removable fuse including first and second terminal elements and a fusible element electrically connected therebetween, the fusible element defining a circuit path configured to operate according to a continuous time-current curve representing time-current conditions that the fusible element can actually withstand before permanently opening;
line side and load side terminals in the housing and electrically connecting to the respective first and second terminal elements of the removable fuse when the removable fuse is received and engaged with the housing, wherein the line side terminal includes a first stationary switch contact;
line and load side fuse clips in the housing, wherein the line side fuse clip includes a second stationary switch contact;
first and second movable switch contacts in the housing, the first and second movable switch contacts mechanically coupled to one another and selectively positionable relative to the respective first and second stationary switch contact in an open position or a closed position to respectively disconnect or connect an electrical connection through the line side terminal and the line side fuse clip and through the circuit path of the fusible element while the terminal elements of the removable fuse are engaged to the line side and load side fuse clips;
an in-line current detecting element configured to detect, at a location upstream from the circuit path of the fusible element, current flow through the first and second switchable contacts and to the circuit path of the fusible element when the first and second switchable contacts are in the closed position; and
a disconnect mechanism operable in a first mode and a second mode to displace the first and second movable switch contacts, wherein the first mode is manually operated and wherein the second mode is automatically responsive in a longer duration overcurrent event to an assessment of whether the fusible element is expected to withstand the detected current flow in the longer duration overcurrent event, wherein the assessment includes a time-based and magnitude-based comparison of the detected current flow relative to the continuous time-current curve of the removable fuse that is directly received and engaged in the housing.

14. The fusible switch disconnect device of claim 13 , wherein the disconnect mechanism includes a solenoid.

15. The

Assignees

• Eaton Intelligent Power Ltd

Inventors

• Darr Matthew Rain
• Kamath Hundi Panduranga

Classifications

• H01H1/20 Primary

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

• H01H21/16

  Adaptation for built-in fuse · CPC title

• H01H9/104

  with interlocking mechanism between switch and fuse · CPC title

• H01H9/102

  Fuses mounted on or constituting the movable contact parts of the switch · CPC title

• H01H2071/0278

  with at least one of juxtaposed casings dedicated to an auxiliary device, e.g. for undervoltage or shunt trip · CPC title