Circuit breakers with shaped neutral busbars and/or load terminals and related methods

Patent metadata

Field	Value
Publication number	US-10032590-B2
Application number	US-201615133676-A
Country	US
Kind code	B2
Filing date	Apr 20, 2016
Priority date	Apr 20, 2016
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

Arc Fault Circuit Interrupter (AFCI), Ground Fault Circuit Interrupter (GFCI) or AF/GF circuit breakers which may optionally have relatively small or compact bodies that have shaped neutral busbars and/or load terminals with an arm that extends through a window of a current transformer in a circuit breaker housing. The neutral busbar and/or load terminal can have a rigid or semi-rigid shaped body with a first segment that extends through the window of the current transformer and a second segment that extends behind the first segment about a printed circuit board. A plug-on, pigtail or bolt-on neutral can engage an electrical pad of the neutral busbar.

First claim

That which is claimed is:

1. A circuit breaker, comprising:
a circuit breaker housing;
a current transformer in the housing, the current transformer comprising a window;
a printed circuit board (PCB) in the housing, wherein the window of the current transformer has an open through channel facing a side of the PCB with a perimeter contour with a recessed segment, wherein the recessed segment of the PCB extends across the open through channel of the current transformer, with a portion of the open through channel above the recessed segment of the PCB and a portion of the channel below the recessed segment of the PCB;
a collar assembly in the housing residing adjacent the open through channel of the current transformer on a side of the open through channel of the current transformer opposing the recessed segment of the PCB, wherein the collar assembly comprises a channel; and
a neutral busbar in the housing, wherein the neutral busbar has a rigid or semi-rigid shaped body with a first segment that extends through the window of the current transformer and into the channel of the collar assembly and a second segment that extends behind the first segment and is attached to the PCB,
wherein the circuit breaker housing comprises a bottom base member with an internal facing curved cavity, a cooperating middle base member, and a cooperating top cover that attach together, wherein the middle base member holds the PCB over the bottom base member and inside the top cover, and wherein the internal facing curved cavity holds the current transformer under a window in the middle base member adjacent a load side of the circuit breaker with the portion of the open through channel above the recessed segment of the PCB and the portion of the channel below the recessed segment of the PCB.

2. The circuit breaker of claim 1 , wherein the neutral busbar second segment has connectors/connector features that directly engage mating connectors/connector features on the PCB to electrically connect and fixedly attach the neutral busbar to the PCB without requiring welding.

3. A circuit breaker, comprising:
a circuit breaker housing;
a current transformer in the housing, the current transformer comprising a window;
a printed circuit board (PCB) in the housing, wherein the window of the current transformer has an open through channel facing a side of the PCB with a perimeter contour with a recessed segment, wherein the recessed segment of the PCB extends across the open through channel of the current transformer, with a portion of the open through channel above the recessed segment of the PCB and a portion of the channel below the recessed segment of the PCB;
a collar assembly in the housing residing adjacent the open through channel of the current transformer on a side of the open through channel of the current transformer opposing the recessed segment of the PCB, wherein the collar assembly comprises a channel; and
a neutral busbar in the housing, wherein the neutral busbar has a rigid or semi-rigid shaped body with a first segment that extends through the window of the current transformer and into the channel of the collar assembly and a second segment that extends behind the first segment and is attached to the PCB,
wherein the shaped body of the neutral busbar has a self-supporting three dimensional shape, wherein the first segment of the neutral busbar is orthogonal to the second segment, wherein the first segment is a straight planar arm that extends straight through the window of the current transformer into the channel of the collar assembly, wherein the current transformer has a cylindrical body with an outer diameter and an inner diameter that surrounds the window of the current transformer, wherein the outer diameter and the inner diameter are parallel to the recessed segment of the PCB, and wherein an inner facing side of the cylindrical body abuts the recessed segment of the PCB.

4. The circuit breaker of claim 1 , wherein the neutral busbar has a unitary, monolithic shaped body that provides a direct electrical neutral current path between the PCB and the collar assembly.

5. The circuit breaker of claim 1 , wherein the first segment of the neutral busbar has a straight planar arm with a first width that merges into an outer free end that extends at least partially into the channel of the collar assembly.

6. The circuit breaker of claim 1 , wherein the circuit breaker is an Arc Fault (AF) Circuit Interrupter (AFCI) circuit breaker, a Ground Fault (GF) Circuit Interrupter (GFCI) circuit breaker, or an AF/GF circuit breaker, and wherein a neutral conductor extends into the housing adjacent and external to the current transformer and couples to the second segment of the neutral busbar to thereby electrically connect the neutral conductor to the neutral busbar.

7. The circuit breaker of claim 1 , wherein the second segment of the neutral busbar comprises connector/connector features that engage aligned connectors/connector features of the PCB, and wherein the second segment of the neutral busbar terminates adjacent the connectors/connector features of the PCB on the load side of the circuit breaker.

8. The circuit breaker of claim 1 , wherein the first segment has a length L 1 that is greater than a length L 2 of the second segment, wherein the first segment has a planar arm with a primary surface that is orthogonal to a plane of a primary surface of the PCB, and wherein the second segment has a straight bridging arm that resides above neutral busbar connection/connector features on the PCB.

9. The circuit breaker of claim 1 , wherein the second segment comprises a planar pad that is parallel to a plane of a primary surface of the PCB and that resides closer to a front of the housing at the load side of the circuit breaker than a laterally extending arm of the second segment.

10. The circuit breaker of claim 1 , wherein the neutral bus bar is non-electrically insulated, the circuit breaker further comprising a load terminal having a rigid or semi-rigid shaped body with a first planar and non-electrically insulated segment that extends through the current transformer window spaced apart from and parallel to the first segment of the neutral busbar and a second segment that extends internal to the housing.

11. The circuit breaker of claim 10 , wherein the second segment of the load terminal is orthogonal to the first segment and has an arm with a first width merging into an internal end that has a greater width.

12. The circuit breaker of claim 1 , wherein the second segment of the neutral busbar terminates adjacent connectors/connector features of the PCB on the load side of the circuit breaker.

13. A circuit breaker, comprising:
a housing;
a current transformer in the housing, the current transformer comprising a window;
a printed circuit board (PCB) in the housing, wherein the window of the current transformer has an open through channel facing a side of the PCB;
a collar assembly in the housing residing adjacent the open through channel of the current transformer on a side of the open through channel of the current transformer opposing the PCB, wherein the collar assembly comprises a channel; and
a neutral busbar in the housing, wherein the neutral busbar has a rigid or semi-rigid self-supporting three-dimensional shaped body with a first segment that extends through the window of the current transformer and into the channel of the collar assembly and a second segment that extends behind the first segment and is attached to the PCB, wherein the second segment of the neutral busbar terminates adjacent connectors/connector features of the PCB on a load side of the circuit break

Assignees

• Eaton Intelligent Power Ltd

Inventors

• Hiremath Somashekharayya
• Jimenez Sandy Omar

Classifications

• H01H2083/148

  with primary windings formed of rigid copper conductors · CPC title

• H01H2083/201

  the other abnormal electrical condition being an arc fault · CPC title

• H01H83/226

  with differential transformer · CPC title

• H01F38/20

  Instruments transformers · CPC title

• H01H71/02 Primary

  Housings; Casings; Bases; Mountings · CPC title