GB2290182A

GB2290182A - Circuit interrupter with keypad and display unit

Info

Publication number: GB2290182A
Application number: GB9510441A
Authority: GB
Inventors: Raymond Kelsey Seymour; Paul Hamilton Singer
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1994-06-10
Filing date: 1995-05-23
Publication date: 1995-12-13
Anticipated expiration: 2015-05-23
Also published as: GB2290182B; GB9510441D0

Abstract

A circuit interrupter employing an electronic trip unit having a keypad and display to enter and display stored trip values and trip data, further includes an auxiliary keypad and display 4. The auxiliary keypad and display can be located a remote distance from the circuit breaker to allow remote indication of the trip status and parameters as well as allowing remote access to the trip unit circuit. The auxiliary unit 4 may be connected to the main trip unit by a ribbon connector 9. The unit 4 may include a printed wire board 3 and a casing 1 with a cover 5, 6. <IMAGE>

Description

CIRCUIT INTERRUPTER This invention relates to circuit interrupters.

Electronic trip units have been used in circuit interrupters, or breakers, initially for sensing current.

The current values when combined with time determine when the circuit breaker is to trip and the electronic trip unit issues a trip signal to a latching relay type flux shifter.

The flux shifter in turn provides the mechanical energy necessary to trip the circuit breaker. In recent years microprocessors have been added to the electronics to provide digital accuracy in sensing current and when combined with other system voltage inputs are used to calculate energies and other ground leakage energies. With the complexity of sensing and reporting liquid crystal displays with keypad setup have been added to the trip units to provide metering display and flags that indicate why the circuit breaker tripped such as over current, ground fault or short circuit. Trip time characteristic can be adjusted to suit the application selected or adjusted using a keypad entry system that is coincident with the display. In some cases the trip unit is mounted in an inaccessible position or is covered by equipment panels or doors and is not visible.

According to the present invention a circuit interrupter including and electronic trip unit for interrupting circuit current upon occurrence of an overload comprises a first keypad and display on a surface of said circuit interrupter for entering overcurrent parameters and displaying such parameters upon request as well as displaying trip indication data; and a second keypad and display at a location remote from said circuit interrupter for entering overcurrent parameters and displaying trip indication upon request.

The circuit interrupter may include a case and a cover and a printed wire board within said case whereby said second keypad and display is mounted on said printed wireboard within said case. An outer cover may be hinged to the cover, the outer cover including an access hole providing access to the keypad.

Conveniently, a ribbon connector on the printed wire board connects between the first and second keypads and displays.

The cover may include a pair of snap fingers extending downward from opposite sides of said cover and said case includes web surfaces on opposite sides of said case, said snap fingers being retained within said web surfaces to hold said cover to said case.

Conveniently, the cover includes hinges formed on a top surface and said outer cover includes hinge pins formed on a bottom surface, said hinge pins being received in said hinges to hold said outer cover to said cover.

The cover may further include a latch on said top surface for receipt within a slot formed in said outer cover for attaching said outer cover to said cover.

In one embodiment the case includes receiving studs extending upward from a bottom surface and said cover includes hollow columns extending downward from a bottom surface, said columns being located over said studs to locate and position said cover on said case.

A column may extend from the bottom surface of the case around the access hole where one is provided.

According to a further aspect of the present invention, an enclosure for a keypad and display unit comprises a case and a cover; a printed wire board within said case, said printed wire board being adapted for receiving a circuit breaker keypad and display unit.

The enclosure of this aspect of the present invention may include those features described above in relation to the circuit interrupter according to the first recited aspect of the present invention.

Embodiments of the present invention provide an auxiliary display that is attached to the main trip unit via cable and that allows the user to mount the auxiliary display in a visible more remote location for viewing and/or system setup. The display can exactly duplicate the action of the main display and allows the user to use either display keypad to setup the circuit breaker trip requirements.

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 is an exploded perspective view of the remote display module; Figure 2 is a side cross section view of the case and cover configuration showing the snap assembly and printed wiring board and its retention means; Figure 3 is an end cross section view of the auxiliary display showing the snap hinge configuration; and Figure 4 is an end cross section view of the auxiliary display showing the clear cover snap installation.

The auxiliary display unit shown in figure 1 is comprised of a thermoplastic case 1 that is mounted by the user using a threaded stud 2 that is pressed through the bottom of said case and protrudes through the back of the case so that a nut can secure the case to most any user surface. The studs 2 are placed at opposite corners of the case 1. The opposing locations provide mounting for a connector printed wiring board 3 used to connect a keypad display 4. Posts 7 cooperate with columns 8 of a cover 5 to locate the printed wiring board 3 that is held in place when the cover 5 is snapped in place. A ribbon cable connector 9 is used to interface the keypad display 4 to a main trip unit (not shown) through the connector printed wiring board 3. The cover 5 and case 1 snap together when snap fingers 10 engage with web surfaces 11 of the case 1 as more clearly pictured in Figure 2.

A hinged cover 6 (shown in figure 1) snaps under partial hinges 12 molded in the cover 5. A latch 13 molded as part of the cover 5 with barbed surfaces secured the cover 6 in the closed position.

The hinged cover is molded of a clear thermoplastic material so that the display keypad 4 and its display information can be seen through the transparent material.

An access hole 14 through the hinged cover 6 is provided so that the user can operate the keypad portion of the keypad display 4 during normal operation.

A collar 15 formed in the hinged cover 6 prevents the user from pressing the enter key thus changing the circuit breaker tripping characteristics if the cover is closed.

The hinged cover 6 can be secured using a seal threaded through a hole in a latch 13. The seal prevents access to the enter button and thus prevents circuit breaker tripping characteristics from being changed.

All other display functions can be accessed through the access hole 14 in the hinged cover 6.

Figure 3 shows a cross section of the auxiliary display where a molded section of the hinged cover 6 forms a partial hinge 12. A portion of the molded cover 6 serves as a hinge pine 16 (shown more clearly in figure 1) that allows the hinged cover 6 to be rotated 90 degrees to an open position.

A ledge 15 portion cover 5 (shown in Figure 1) prevents the cover 6 from falling out. This is accomplished by making the distance between the hinge 12 and the ledge 15 slightly less than the thickness of the hinge pin 16 portion of the hinged cover 6. In addition a wiper surface 17 molded as part of the cover 6 rides on top of hinge 12 keeping the hinge pin 16 in place.

Assembly of said hinged cover 6 to said cover 5 is shown in Figure 4 where the hinged cover 6 is installed vertically at first with the hinge pin 16 portion of the hinged cover 6 forced between the hinge 12 and the ledge 15. The cover may now be forced in the horizontal position where the hinge pin 16 snaps under the partial hinge 12.

The assembly is now free to rotate to its open or closed position as shown in Figure 3.

The hinged cover stays in the open position because of the flat nature of the hinge pin 16 riding in the radius portion of the hinge 12 and the flat surface of cover 5.

This action provides a detented open position that is easily rotated by the user to the closed position.

Claims

1. A circuit interrupter including an electronic trip unit for interrupting circuit current upon occurrence of an overload comprising: a first keypad and display on a surface of said circuit interrupter for entering overcurrent parameters and displaying such parameters upon request as well as displaying trip indication data; and a second keypad and display at a location remote from said circuit interrupter for entering overcurrent parameters and displaying trip indication upon request.

2. The circuit interrupter of claim 1 including: a case and a cover; a printed wire board within said case; whereby said second keypad and display is mounted on said printed wireboard within said case.

3. The circuit interrupter of claim 2 including an outer cover hinged to said cover, said outer cover including an access hole providing access to said keypad.

4. The circuit interrupter of claim 2 including a ribbon connector on said printed wire board, said ribbon connector connecting between said first and second keypads and displays.

5. The circuit interrupter of claim 2 wherein said cover includes pair of snap fingers extending downward from opposite sides of said cover and said case includes web surfaces on opposite sides of said case, said snap fingers being retained within said web surfaces to hold said cover to said case.

6. The circuit interrupter of claim 3 wherein said cover includes hinges formed on a top surface and said outer cover includes hinge pins formed on a bottom surface, said hinge pins being received in said hinges to hold said outer cover to said cover.

7. The circuit interrupter of claim 3 wherein said cover further includes a latch on said top surface for receipt within a slot formed in said outer cover for attaching said outer cover to said cover.

8. The circuit interrupter of claim 2 wherein said case includes receiving studs extending upward from a bottom surface and said cover includes hollow columns extending downward from a bottom surface, said columns being located over said studs to locate and position said cover on said case.

9. The circuit interrupter of claim 3 including a collar extending said from said bottom surface of said case around said access hole.

10. An enclosure for a keypad and display unit comprising: a case and a cover; a printed wire board within said case, said printed wireboard being adapted for receiving a circuit breaker keypad and display unit.

11. The enclosure of claim 10 including an outer cover hinged to said cover, said outer cover including an access hole 14 providing access to said keypad.

12. The enclosure of claim 10 including an a ribbon connector on said printed wire board, said ribbon connector connecting said keypad and display unit with a remote keypad and display unit.

13. The enclosure of claim 10 wherein said cover includes a pair of snap fingers extending downward from opposite sides of said cover and said case includes web surfaces on opposite ends of said case, said snap fingers being retained within said web surfaces to hold said cover to said case.

14. The enclosure of claim 11 wherein said cover includes hinges formed on a top surface and said outer cover includes hinge pins formed on a bottom surface, said hinge pins being received in said hinges to hold said outer cover to said cover.

15. The enclosure of claim 11 wherein said cover further includes a latch on said top surface for receipt within a slot formed in said outer cover for attaching said outer cover to said cover.

16. The enclosure of claim 10 wherein said case includes receiving studs extending upward from a bottom surface and said cover includes hollow columns extending downward from a bottom surface, said columns being located over said studs to locate and position said cover on said case.

17. The enclosure of claim 11 wherein said case includes a collar 15 extending said from said bottom surface of said case around said access hole.

18. A circuit interrupter substaatially as hereinbefore described with reference to the accompanying drawings.

19. An enclosure substantially as hereinbefore described with reference to the accompanying drawings.