Circuit breaker accessory cover interlock and forced safety tripping apparatus, systems, and methods

Patent metadata

Field	Value
Publication number	US-10418197-B2
Application number	US-201715659240-A
Country	US
Kind code	B2
Filing date	Jul 25, 2017
Priority date	Jul 25, 2017
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

A circuit breaker having a housing with an accessory cover includes an accessory cover interlock assembly that trips the circuit breaker upon removal of the accessory cover. The accessory cover interlock assembly includes a plunger rotatable from an initial install position to an engaged position that moves a trip lever into a de-energize position (tripping the circuit breaker) upon removal of the accessory cover. The accessory cover interlock assembly prevents the circuit breaker from being reset while the access cover is removed. The accessory cover interlock assembly automatically resets upon re-attachment of the accessory cover to the circuit breaker housing. Methods of forced safety tripping in a circuit breaker are also provided, as are other aspects.

First claim

What is claimed is:

1. An accessory cover interlock assembly for a circuit breaker, comprising:
a plunger having a longitudinal axis and an elongated body, the elongated body along the longitudinal axis, the plunger rotatable about the longitudinal axis from an install position to an engaged position, the elongated body having a head at a first end thereof, a foot extending perpendicularly outward from a second end thereof, and a planar lock portion located between the first end and the second end,
wherein, in the engaged position, the foot is positioned beneath a trip lever and is configured to move the trip lever from an energized position to a de-energized position in response to removal of an accessory cover;
a retaining member disposed about the elongated body between the first end and the planar lock portion;
a spring disposed about the elongated body between the retaining member and the foot; and
a cap having an opening, the cap seated on the head of the elongated body,
wherein the accessory cover interlock assembly trips a circuit breaker upon removal of the accessory cover,
wherein the accessory cover interlock assembly prevents the circuit breaker from being reset while the access cover is removed, and
wherein the accessory cover interlock assembly automatically resets upon re-attachment of the accessory cover to the circuit breaker.

2. The accessory cover interlock assembly of claim 1 , wherein the elongated body has a groove about a circumference thereof proximate to the head, and the retaining member is held in place in the groove.

3. The accessory cover interlock assembly of claim 1 , wherein the spring is a stainless steel coil spring having a free length ranging from 27.0 mm to 29.0 mm and a spring rate ranging from 3.2 N/mm to 3.7 N/mm.

4. The accessory cover interlock assembly of claim 1 , wherein the retaining member is a stainless steel type E retaining ring.

5. The accessory cover interlock assembly of claim 1 , wherein the cap has an outside diameter ranging from 7.8 mm to 8.2 mm and a depth measured along a length of the elongated body ranging from 3.8 mm to 4.2 mm.

6. An accessory cover interlock assembly for a circuit breaker, comprising:
a plunger having an elongated body, the elongated body having a head at a first end thereof, a foot extending perpendicularly outward from a second end thereof, and a planar lock portion located between the first end and the second end;
a retaining member disposed about the elongated body between the first end and the planar lock portion;
a spring disposed about the elongated body between the retaining member and the foot; and
a cap having an opening, the cap seated on the head of the elongated body, wherein the plunger has a length ranging from 40.0 mm to 43.0 mm, the planar lock portion has a length ranging from 5.0 mm to 7.0 mm located a distance from the second end ranging from 13.0 mm to 14.0 mm, and the foot extends a distance perpendicularly outward from the elongated body ranging from 4.0 mm to 8.0 mm.

7. The accessory cover interlock assembly of claim 6 , wherein the elongated body has a groove about a circumference thereof proximate to the head, and the retaining member is held in place in the groove.

8. The accessory cover interlock assembly of claim 6 , wherein the spring is a stainless steel coil spring having a free length ranging from 27.0 mm to 29.0 mm and a spring rate ranging from 3.2 N/mm to 3.7 N/mm.

9. The accessory cover interlock assembly of claim 6 , wherein the retaining member is a stainless steel type E retaining ring.

10. The accessory cover interlock assembly of claim 6 , wherein the cap has an outside diameter ranging from 7.8 mm to 8.2 mm and a depth measured along a length of the elongated body ranging from 3.8 mm to 4.2 mm.

11. A method of providing an accessory cover interlock assembly for a circuit breaker, comprising:
providing a plunger having a longitudinal axis and an elongated body, the elongated body along the longitudinal axis, the plunger rotatable about the longitudinal axis from an install position to an engaged position, the elongated body having a head at a first end thereof, a foot extending perpendicularly outward from a second end thereof, and a planar lock portion located between the first end and the second end,
wherein, in the engaged position, the foot is positioned beneath a trip lever and is configured to move the trip lever from an energized position to a de-energized position in response to removal of an accessory cover;
providing a retaining member disposed about the elongated body between the first end and the planar lock portion;
providing a spring disposed about the elongated body between the retaining member and the foot; and
providing a cap having an opening, the cap seated on the head of the elongated body,
wherein the accessory cover interlock assembly trips a circuit breaker upon removal of the accessory cover,
wherein the accessory cover interlock assembly prevents the circuit breaker from being reset while the access cover is removed, and
wherein the accessory cover interlock assembly automatically resets upon re-attachment of the accessory cover to the circuit breaker.

12. The method of claim 11 , wherein the elongated body has a groove about a circumference thereof proximate to the head, and the retaining member is held in place in the groove.

13. The method of claim 11 , wherein the plunger has a length ranging from 40.0 mm to 43.0 mm, the planar lock portion has a length ranging from 5.0 mm to 7.0 mm located a distance from the second end ranging from 13.0 mm to 14.0 mm, and the foot extends a distance perpendicularly outward from the elongated body ranging from 4.0 mm to 8.0 mm.

14. The method of claim 11 , wherein the spring is a stainless steel coil spring having a free length ranging from 27.0 mm to 29.0 mm and a spring rate ranging from 3.2 N/mm to 3.7 N/mm.

15. The method of claim 11 , wherein the retaining member is a stainless steel type E retaining ring.

16. The method of claim 11 , wherein the cap has an outside diameter ranging from 7.8 mm to 8.2 mm and a depth measured along a length of the elongated body ranging from 3.8 mm to 4.2 mm.

Assignees

• Siemens Ag

Inventors

• Rojko Jan
• Sizemore Jorg
• Cowans John Quentin

Classifications

• H01H71/002

  with provision for switching the neutral conductor · CPC title

• H01H9/22 Primary

  for interlocking between casing, cover, or protective shutter and mechanism for operating contacts {(explosion-proof cases H01H9/045; built-in fuses and interlocking mechanisms H01H9/104; by automatic release of circuit breakers H01H71/126)} · CPC title

• H01H71/126

  actuated by dismounting of circuit breaker or removal of part of circuit breaker · CPC title

• H01H2071/0292

  Housing or frames containing grooves or slots for guiding movable parts · CPC title

• H01H2071/004

  with a tripping or current sensing device in the neutral wire, e.g. for third harmonics in a three fase system · CPC title