Siemens Industry, Inc.

Hugh T Kinsel

Joselito Endozo

Carlos Eduardo Restrepo

James Edward Ferree

Amit Nayak

Jorg Sizemore

Barry R Contrael

Brian Timothy McCoy

Russell Thomas Watford

Vaske Mikani

Mario Bilac

Solomon R Titus

Peter Staley

Raiden Jay Kim

William P Hooper

Susan Sneed Hooper, Legal Representative

Peter S Staley

Carlos Restrepo

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.

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

A circuit breaker distribution system is configured to provide selective coordination. The system comprises a solid-state switch disposed as a main or upstream breaker and a switch with an over current protection disposed as a branch or downstream breaker. The solid-state switch comprises a microcontroller to: allow repeated pulses of current through to the branch or downstream breaker in an event of an overload or short circuit, choose a maximum current limit for the solid-state switch as a 'chop level' such that the chop level is chosen higher than a rated current of the solid-state circuit breaker but low enough that the solid-state switch is not damaged from repeated pulses over a period of time needed to switch OFF the branch or downstream breaker, and add a pulse interval which is optimized to a system voltage waveform in that chopped pulses tend to be longer and more effective for de-latching the branch or downstream breaker when they occur in vicinity of a zero crossing of the system voltage waveform and chopped pulses are shorter and less effective near peaks of the system voltage waveform.

Circuit breaker distribution system configured to provide selective coordination

A circuit breaker distribution system is configured to provide selective coordination. The system comprises a solid-state switch disposed as a main or upstream breaker and a switch with an over current protection disposed as a branch or downstream breaker. The microcontroller to: allow repeated pulses of current through to the branch or downstream breaker in an event of an overload or short circuit, choose a maximum current limit for the solid-state switch as a 'chop level' such that the chop level is chosen higher than a rated current of the solid-state circuit breaker but low enough that the solid-state switch is not damaged from repeated pulses over a period of time needed to switch OFF the branch or downstream breaker and add a pulse interval after the current chops to zero but before the solid-state circuit breaker returns to an ON state for a next pulse to begin.

A circuit breaker distribution system is configured to provide selective coordination. The system comprises a solid-state switch disposed as a main or upstream breaker and a switch with an over current protection disposed as a branch or downstream breaker. The solid-state switch comprises a microcontroller including a processor and a memory, and computer-readable logic code stored in the memory which, when executed by the processor, causes the microcontroller to: allow repeated pulses of current through to the branch or downstream breaker in an event of an overload or short circuit, and choose a maximum current limit for the solid-state switch as a 'chop level' such that the chop level is chosen higher than a rated current of the solid-state circuit breaker but low enough that the solid-state switch is not damaged from repeated pulses over a period of time needed to switch OFF the branch or downstream breaker.

A circuit interrupting device with overload current detection is provided. It comprises a hot conductor, a main contactor and a first electromagnetic device configured to remove power from an electrical circuit when overload current exceeds a predetermined % of a rated load current. It further comprises a section of conductor that generates heat and a thermal overload current detection mechanism including a temperature sensing switch having contacts. The temperature sensing switch closes the contacts when a temperature reaches a predefined temperature threshold corresponding to an overload current, in which case the temperature sensing switch electrically couples power to a second electromagnet which is disposed across the hot conductor and a connection to a neutral conductor. The energized second electromagnet generates a magnetic force capable of moving an armature that unlatches the latch releasing the spring to open the main contactor removing power from the electrical circuit.

Overload current detection in a circuit interrupting device

A circuit interrupting device with a temperature activated permanent lockout trip mechanism is provided. The temperature activated permanent lockout trip mechanism is located in close proximity to a section of conductor that generates heat. An energized first solenoid generates a magnetic force capable of moving an armature that unlatches a latch releasing a spring to open a main contactor removing power from an electrical circuit. The temperature activated permanent lockout trip mechanism upon reaching a predetermined temperature which is higher than the predetermined temperature threshold of the temperature sensing switch also generates a mechanical force capable of moving the armature that unlatches the latch releasing the spring to open the main contactor removing power from the electrical circuit. Once activated, the temperature activated permanent lockout trip mechanism inhibits the latch from latching which prevents a reset of the circuit interrupting device thus the circuit interrupting device is permanently disabled as the main contactor cannot be closed, and power no longer be reconnected to the electrical circuit.

Fail-safe lockout trip mechanism in a circuit interrupting device

An arc fault detection circuit interruption (AFCI) device includes a high frequency arc noise sensor and an arc fault detection circuit for sensing a high frequency arc noise. The high frequency arc noise sensor is disposed across a hot conductor and a neutral conductor and includes a surge protection device and a surge protection circuit such that the surge protection device protects against a first voltage surge in a first range of thousands to hundreds volts and the surge protection circuit protects against a second voltage surge in a second range of hundreds to few volts. The arc fault detection circuit is coupled in series with the high frequency arc noise sensor. The arc fault detection circuit is coupled to a series combination of a trip solenoid or electromagnet and a silicone-controlled rectifier disposed across the hot conductor and the neutral conductor.

Sensing a high frequency arc noise in an arc fault detection circuit interruption (AFCI) device

An electronic circuit breaker may include a monitoring circuit configured to monitor and respond to a power supply and/or detection circuit failure within the electronic circuit breaker. In some embodiments, the monitoring circuit may monitor a DC current received from a detection circuit within the electronic circuit breaker. A response to a power supply and/or detection circuit failure may include interrupting current flow between an electrical power source and an electrical circuit protected by the electronic circuit breaker. Methods of monitoring and responding to a power supply and/or detection circuit failure within an electronic circuit breaker are also provided, as are other aspects.

Apparatus and methods for monitoring and responding to power supply and/or detection circuit failures within an electronic circuit breaker

A ground fault circuit interrupter (GFCI) having an automatic self-test feature is configured to disable a trip circuit therein during a self test, yet still allow the trip circuit to respond during the self test to detection of a large ground fault by tripping a main contact switch of the GFCI. The GFCI includes circuitry that overrides the disablement of the trip circuit during a self test in response to detection of a ground fault that exceeds a predetermined threshold. Methods of disabling a trip circuit of a GFCI during a self test while still allowing the trip circuit to respond during the self test to detection of a large ground fault are also provided, as are other aspects.

Methods and apparatus to disable a trip circuit during self test in ground fault circuit interrupters

A multi-pole circuit interrupter configured to be coupled between an AC source and an electric load electronically detects a hazardous condition associated with energizing of poles and responds to overcome the hazardous condition using a solenoid. The multi-pole circuit interrupter comprises a first switch to energize a first pole on a phase A conductor of the multi-pole circuit interrupter and a second switch to energize a second pole on a phase B conductor of the multi-pole circuit interrupter. The multi-pole circuit interrupter further comprises an electronic solid-state circuit coupled to the phase A conductor and the phase B conductor to detect a line voltage variation and control a current to a device in response to trip an energized pole among the first pole and the second pole if only one of the first pole and the second pole is energized when a user controls a tie bar to turn ON or turn OFF the multi-pole circuit interrupter or when a trip bar fails to trip one of the first pole and the second pole.

Monitoring and responding to an abnormal condition associated with energizing of poles of a circuit breaker

An electronic circuit breaker may include a monitoring circuit configured to monitor and respond to a power supply and/or detection circuit failure within the electronic circuit breaker. In some embodiments, the monitoring circuit may monitor a regulated DC voltage provided by the detection circuit within the electronic circuit breaker. A response to a power supply and/or detection circuit failure may include interrupting current flow between an electrical power source and an electrical circuit protected by the electronic circuit breaker. Methods of monitoring and responding to a power supply and/or detection circuit failure within an electronic circuit breaker are also provided, as are other aspects.

In one aspect, a method of electrical arc fault detection when high frequency (e.g., RF noise) is present is disclosed. The method includes determining if first arcing criterion is met, determining if delay criterion is met, implementing a delay for a delay period if the delay criterion is met, and determining if second arcing criterion is met. If the second arcing criterion is met, then a trip signal may be sent to trip the circuit breaker. In another aspect, the method includes determining if first arcing criterion is met, starting delay period if the first arcing criterion is met, determining if delay criterion is met, and if the delay criterion is met, determining if second arcing criterion is met. An arc fault detection apparatus adapted to carry out the methods, and systems including the arc fault detection apparatus are disclosed, as are various other aspects.

Arc fault circuit detection methods, systems, and apparatus including delay

In a first aspect, a ground fault circuit interrupt ('GFCI') device is provided for use with an AC power system that includes a line conductor, a neutral conductor and a transformer. The line conductor and the neutral conductor are each coupled between a source and a load, and the neutral conductor is coupled to ground at the source. The transformer includes a first primary winding coupled in series with the line conductor, a second primary winding coupled in series with the neutral conductor, and a secondary winding. The device includes a grounded neutral fault detector circuit coupled to the secondary winding. The grounded neutral fault detector circuit: (a) drives the secondary winding with a multi-frequency AC signal, (b) monitors a multi-frequency load signal in the secondary winding, and (c) provides a first detection signal if the monitored load signal exceeds a predetermined threshold. Numerous other aspects are also provided.

Methods and apparatus for multi-frequency ground fault circuit interrupt grounded neutral fault detection

A device is provided for use with an AC power system having a line conductor, a neutral conductor and a transformer, the line conductor and the neutral conductor are coupled between a source and a load, and the transformer includes a first primary winding coupled in series with the line conductor, a second primary winding coupled in series with the neutral conductor, and a secondary winding. The device includes a first circuit coupled to the secondary winding, providing a first detection signal if a current from the line conductor to ground exceeds a first predetermined threshold, and a second circuit coupled to the secondary winding, having a source that provides an AC signal at a specified amplitude and a specified frequency to the secondary winding. The second circuit provides a second detection signal if an impedance between the neutral conductor and ground is less than a second predetermined threshold.

Methods and appratus for ground fault circuit interrupt detection using a single transformer

An apparatus and method for a supervisory circuit for a ground fault detection device or a ground fault circuit interrupt (GFCI) device is disclosed in which a low voltage DC power supply is used to generate a test stimulus signal for a self test of the GFCI device. The GFCI device includes line and neutral conductors configured to connect an AC power source and a load. A differential current transformer includes a toroid, through which the line and neutral conductors pass, and a secondary winding wound on the toroid. A differential ground fault detector is electrically connected to the secondary winding of the differential current transformer to compare current generated in the secondary winding from an imbalance of magnetic flux in the toroid to a trip threshold. A wire conductor is routed through the toroid of the differential current transformer. A controller is configured to control a low voltage DC test stimulus signal to be generated in the wire conductor.

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Sugar Hill, GA, United States of America

Hugh T Kinsel