Circuit interrupting device for providing a fail-safe lock out trip mechanism or a temperature activated, permanent lock out trip mechanism in response to a self-test

Patent metadata

Field	Value
Publication number	US-12176169-B2
Application number	US-202217657979-A
Country	US
Kind code	B2
Filing date	Apr 5, 2022
Priority date	Apr 5, 2022
Publication date	Dec 24, 2024
Grant date	Dec 24, 2024

Abstract

A circuit interrupting device comprises a conductor capable of generating heat and a temperature-activated, permanent lock out trip mechanism. The mechanism includes a plunger, a compressed or stretched spring and a fusible metal to hold the plunger. The mechanism is located near the conductor that generates heat and is configured such that when the fusible metal melts when at least one heating element is energized or a holding wire fuses when energized in response to a failed self-test the plunger is released: allowing the compressed or stretched spring to convert its potential energy into kinetic energy and moving the plunger to generate a force to unlatch a latch releasing a first spring to open a contactor switch removing power from an electrical circuit. The constant force generated by the compressed or stretched spring on the plunger inhibits the circuit interrupting device from resetting.

First claim

What is claimed is:

1. A circuit interrupting device comprising:
a conductor capable of generating heat; and
a temperature-activated, permanent lock out trip mechanism including:
a plunger;
a compressed or stretched spring; and
a fusible metal to hold the plunger in place that has a constant force exerted on it by either the compressed or stretched spring, wherein the temperature-activated, permanent lock out trip mechanism is located near the conductor that generates heat and is configured such that when the fusible metal melts when at least one heating element is energized or a holding wire fuses when energized in response to a failed self-test the plunger is released:
allowing the compressed or stretched spring to convert its potential energy into kinetic energy, and
moving the plunger to generate a force to unlatch a latch releasing a first spring to open a contactor switch removing power from an electrical circuit,
wherein the constant force generated by the compressed or stretched spring on the plunger inhibits the circuit interrupting device from resetting which permanently prevents reconnecting power to the electrical circuit.

2. The circuit interrupting device of claim 1 , wherein the temperature-activated, permanent lock out trip mechanism consists of:
at least one solder holding tube, the holding wire and the at least one heating element; and
a base, wherein the compressed or stretched spring is compressed by the plunger against the base which is integrated into an enclosure of the circuit interrupting device,
wherein the plunger is held in place by the holding wire that is affixed to the base by the fusible metal in at least one solder holding tube, and
wherein the base provides a fixed-point reference for the spring force of the compressed or stretched spring in the temperature-activated permanent lock out trip mechanism.

3. The circuit interrupting device of claim 2 , further comprising:
a trip armature configured to unlatch the latch when force is applied by the plunger releasing the first spring to open the contactor switch removing power from the electrical circuit,
wherein when the temperature of the fusible metal reaches its melting point, the fusible metal becomes a liquid and is no longer affixed to the holding wire allowing the plunger to move in the direction of the trip armature, wherein the force of the compressed or stretched spring against the fixed-point reference of the enclosure or the base and a cap of the plunger moves the plunger in the direction of the trip armature and applies a continuous force on the trip armature such that the applied continuous force moves the trip armature that unlatches the latch releasing the first spring to open the contactor switch thus removing power from the electrical circuit.

4. The circuit interrupting device of claim 3 , wherein the continuous force applied to the trip armature inhibits the latch from latching which permanently prevents a reset, disabling the contactor switch from ever closing again and reconnecting power to the electrical circuit.

5. The circuit interrupting device of claim 4 , wherein a top of the cap of the plunger has a rounded bump that allows for a tangential plane to contact the trip armature to apply a force normal to a plane.

6. The circuit interrupting device of claim 1 , wherein the temperature-activated, permanent lock out trip mechanism to generate a force to unlatch the latch releasing the first spring to open the contactor switch removing power from the electrical circuit in response to a malfunction detected in a trip circuit, or a power supply, or sensors, or any of electronic detection circuits such that the temperature-activated, permanent lock out trip mechanism permanently prevents the circuit interrupting device from being turned back on and re-applying power to the electrical circuit.

7. The circuit interrupting device of claim 1 , further comprising:
heating elements surrounding the fusible metal that is energized in response to a malfunction in a trip circuit, a power supply, sensors, or electronic detection circuits, which melts the fusible metal releasing the plunger allowing the compressed or stretched spring to convert potential energy into kinetic energy, moving the plunger to generate a force to unlatch the latch releasing the first spring to open the contactor switch removing power from the electrical circuit.

8. The circuit interrupting device of claim 1 , wherein the temperature-activated, permanent lock out trip mechanism to generate a force to unlatch the latch releasing the first spring to open the contactor switch removing power from the electrical circuit within calibration trip time limits specified in UL489 should a trip circuit solenoid or electromagnet or a solid-state switch became damaged and/or inoperable, or should a current sensor or an electronic overload current detection circuit/apparatus become damaged or inoperable, or should a self-test module or a watchdog circuit becomes inoperable.

9. The circuit interrupting device of claim 8 , further comprising:
a fail-safe backup mechanism to permanently remove power from the electrical circuit within the calibration trip time limits specified in UL489 should a trip circuit, a current sensor, or an electronic overload current detection circuit/apparatus become damaged or inoperable, or should a self-test module or a watchdog circuit becomes inoperable and or the fail-safe backup mechanism to permanently remove power from the electrical circuit in response to a malfunction in the trip circuit, a power supply, sensors, or any of the electronic detection circuits.

10. The circuit interrupting device of claim 1 , wherein the fusible metal is energized to generate heat in response to a malfunction in a trip circuit, a power supply, sensors, or electronic detection circuits, which melts the fusible metal releasing the plunger allowing the compressed or stretched spring to convert potential energy into kinetic energy, moving the plunger to generate a force to unlatch the latch releasing the first spring to open the contactor switch removing power from the electrical circuit.

11. The circuit interrupting device of claim 1 , wherein a self test of an overload current fault detection circuit and or sensors is provided.

12. The circuit interrupting device of claim 1 , wherein a self test of a ground fault detection circuit and or sensors is provided and wherein a self test of an arc fault detection circuit and or sensors is provided.

13. The circuit interrupting device of claim 1 , wherein a self test of a trip circuit is provided.

14. The circuit interrupting device of claim 1 , further comprising:
a switch to dispose the fusible metal across the conductor capable of generating heat and a neutral conductor.

15. The circuit interrupting device of claim 14 , wherein the switch is a solid-state device including a Triac or a SCR.

16. A method of providing a fail-safe lock out trip mechanism for a circuit interrupting device in response to a self-test, the method comprising:
providing a conductor capable of generating heat; and
providing a temperature-activated, permanent lock out trip mechanism including:
a plunger;
a compressed or stretched spring; and
a fusible metal to hold the plunger in place that has a constant force exerted on it by either the compressed or stretched spring, wherein the temperature-activated, permanent lock out trip mechanism is located near the conductor that generates heat and is configured such that when the fusible metal melts when at least one heating element is energized or a holding wir

Assignees

• Siemens Industry Inc

Inventors

• Kinsel Hugh T
• Endozo Joselito
• Watford Russell Thomas
• Kim Raiden Jay
• Mccoy Brian Timothy

Classifications

• H01H2037/762

  using a spring for opening the circuit when the fusible element melts · CPC title

• H01H85/055

  Fusible members · CPC title

• H01H2235/01

  Spiral spring · CPC title

• H01H83/22

  the other condition being imbalance of two or more currents or voltages · CPC title

• H01H2083/201

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