Differential current sensing bussing method

Patent metadata

Field	Value
Publication number	US-10852326-B2
Application number	US-201715672762-A
Country	US
Kind code	B2
Filing date	Aug 9, 2017
Priority date	Aug 9, 2017
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

The line power and neutral conductors for a circuit interrupter such as a miniature circuit breaker, using ground fault sensing via a current transformer, are arranged as a rigid conductor formed from a flat plate and surrounding and holding an insulated flexible conductor when passing through the Ground Fault Interrupter current transformer. The rigid conductor can provide a shaped current path to maximize the effectiveness of the current transformer.

First claim

The invention claimed is:

1. A circuit interrupter device with line power and neutral return power current paths, and an apertured current transformer configured to detect ground fault current anomalies, comprising:
a substantially rigid conductor surrounding and holding a flexible conductor, the substantially rigid conductor being formed from a flat plate having first and second terminal strips and a wider central portion which has been rolled into a substantially tubular form thereby creating a substantially tubular portion for fitting through the current transformer,
the substantially rigid conductor and the flexible conductor passing through the aperture of the current transformer inside of the circuit interrupter device.

2. The circuit interrupter device of claim 1 wherein the substantially rigid conductor comprises an electrical resistance feature configured to increase resistance to a flow of current through the substantially rigid conductor.

3. The circuit interrupter device of claim 2 wherein the electrical resistance feature is on only one end of the substantially tubular portion.

4. The circuit interrupter device of claim 2 wherein the electrical resistance feature comprises a narrowed wall thickness in a section of the substantially tubular portion.

5. The circuit interrupter device of claim 2 wherein the electrical resistance feature comprises a through hole in a section of the substantially tubular form.

6. The circuit interrupter device of claim 1 wherein the flat plate is twisted about its central axis during formation.

7. The circuit interrupter device of claim 1 wherein the substantially rigid conductor is connected to and forms a part of the neutral return power current path.

8. The circuit interrupter device of claim 1 wherein the circuit interrupter device is a miniature circuit breaker.

Assignees

• Schneider Electric Usa Inc

Inventors

• Fleege Dennis W
• Mittelstadt Chad
• Gass Randall J
• Vanwaart Douglas P
• Potratz Jason

Classifications

• H01H83/14

  operated by imbalance of two or more currents or voltages, e.g. for differential protection · CPC title

• G01R19/16571 Primary

  comparing AC or DC current with one threshold, e.g. load current, over-current, surge current or fault current (G01R19/16514, G01R19/16519, G01R19/16528, G01R19/16533, G01R19/1659 take precedence; measuring currents by using elements sensitive to the magnetic field generated G01R15/14; measuring earth resistance G01R27/18; testing for leakage or short circuits in electrical apparatus G01R31/52) · CPC title

• G01R31/50

  Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections (testing of sparking plugs H01T13/58) · CPC title

• G01R31/52 Primary

  Testing for short-circuits, leakage current or ground faults · CPC title

• H03F3/45183

  Long tailed pairs (H03F3/4521, H03F3/45237 take precedence) · CPC title