Fault indicator in test point cap

• US 3,906,477 A
• Filed: 09/06/1974
• Issued: 09/16/1975
• Est. Priority Date: 09/06/1974
• Status: Expired due to Term

• Current Assignee: Edmund O. Schweitzer Jr
• Original Assignee: Edmund O. Schweitzer Jr
• Inventors: Schweitzer, Edmund O. Jr.
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Myer, Daniel
• Application Number:
  US05/503,719
• Time in Patent Office: 375 Days
• Field of Search: 340/248,253 324/51,133 317/22,23,48
• US Class Current: 324/133
• CPC Class Codes: G01R 19/145 Indicating the presence of current or voltage

Abstract

A plug-in connector for high voltage alternating current circuits includes a conductor embedded in insulating material with a test point terminal capacitively associated therewith together with fault responsive means mounted on the connector and having a target that is shifted to fault indicating position on flow of fault current in the conductor and is reset from the fault indicating position on restoration of energizing voltage to the conductor.

Claims

1. Means responsive to flow of alternating fault current in and high voltage energization of a conductor comprising:

means for responding to current flow in said conductor, first and second capacitor means, rectifier means, conductive circuit means for directly interconnecting said first and second capacitor means in parallel and said conductor through said rectifier means to charge said first and second capacitor means to a unidirectional voltage, and fault indicating means including;

a target, a magnetic core, a trip winding on said core connected to be energized from said first capacitor means in response to operation of said current flow responsive means for moving said target from a non-indicating position to a fault indicating position in response to flow of fault current in said conductor, and a reset winding on said magnetic core connected to be energized from said second capacitor means for moving said target from said fault indicating position to said non-indicating position on application of energizing voltage to said conductor.

2. Current and voltage responsive means according to claim 1 whererein a blocking diode is interposed between said first and second capacitor means in such direction as to effect simultaneous discharge of said first and second capacitor means to energize said trip winding and to prevent discharge of said first capacitor means when said reset winding is energized.

3. Current and voltage responsive means according to claim 1 wherein said means for responding to current flow in said conductor includes reed switch means positioned to be responsive to the alternating magnetic field around said conductor.

4. Current and voltage responsive means according to claim 3 wherein the longitudinal axis of said magnetic core is generally perpendicular to the longitudinal axis of said conductor and the longitudinal axis of said reed switch means is generally parallel to the alternating magnetic field around said conductor.

5. Current and voltage responsive means according to claim 1 wherein said means for responding to current flow in said conductor includes a winding inductively related thereto and rectifier means the output of which corresponds to the magnitude of said current flow in said conductor.

6. Current and voltage responsive means according to Claim 1 wherein said target includes a pivoted permanent magnet arranged to occupy positions 180* apart depending upon the polarity of said magnetic core, and a permanent magnet is stationarily mounted with respect to said pivoted permanent magnet to insure that the latter occupies one or the other of its indicating positions.

7. Current and voltage responsive means according to claim 1 wherein said means for responding to current flow in said conductor includes reed switch means positioned to be responsive to the alternating magnetic field around said conductor and connected to trigger voltage sensitive means connected in series circuit relation with said trip winding.

8. Current and voltage responsive means according to claim 1 wherein said reset winding is arranged to be energized when voltage sensitive switch means connected in series circuit relation therewith is rendered conducting on application of predetermined voltage from said second capacitor means to trigger means connected across said voltage sensitive switch means.

9. In combination, a plug-in connector for high voltage alternating current circuits having:

a conductor embedded in insulating material, and a test point terminal carried by said insulating material and capacitively related to said conductor; and

fault responsive means carried by said connector comprising;

means for responding to current flow in said conductor, capacitor means, rectifier means, circuit means interconnecting said capacitor means and said test point terminal through said rectifier means to charge said capacitor means to a unidirectional voltage; and

fault indicating means including;

a target, a magnetic core, a trip winding on said core connected to be energized from said capacitor means in response to operation of said current flow responsive means for moving said target from a non-indicating position to a fault indicating position in response to flow of fault current in said conductor, and a reset winding on said magnetic core connected to be energized from said capacitor means for moving said target from said fault indicating position to said non-indicating position on application of energizing voltage to said conductor.

10. The plug-in connector and fault responsive means according to claim 9 wherein said capacitor means comprises first and second capacitor means connected in parallel to said rectifier means, said first capacitor means is arranged to energize said trip winding on said flow of fault current in said conductor, and said second capacitor means is arranged to energize said reset winding on said application of energizing voltage to said conductor.

11. The plug-in connector and fault responsive means according to claim 9 wherein a blocking diode is interposed between said first and second capacitor means in such direction as to effect simultaneous discharge of said first and second capacitor means to energize said trip winding and to prevent discharge of said first capacitor means when said reset winding is energized.

12. The plug-in connector and fault responsive means according to claim 9 wherein said means for responding to current flow in said conductor includes reed switch means positioned to be responsive to the alternating magnetic field around said conductor.

13. The plug-in connector and fault responsive means according to claim 12 wherein the longitudinal axis of said magnetic core is generally perpendicular to the longitudinal axis of said conductor and the longitudinal axis of said reed switch means is generally parallel to the alternating magnetic field around said conductor.

14. The plug-in connector and fault responsive means according to claim 9 wherein said means for responding to current flow in said conductor includes a winding inductively related thereto and rectifier means the output of which corresponds to the magnitude of said current flow in said conductor.

15. The plug-in connector and fault responsive means according to claim 9 wherein said plug-in connector has an outstanding flange integral with said insulating material, and said fault responsive means is enclosed in a housing telescoped with said flange.

16. The plug-in connector and fault responsive means according to claim 15 wherein said circuit means is detachably connected to said test point terminal.