A circuit breaker having a frame comprises a bimetal plate having a longitudinal length wherein the bimetal plate is cut along the longitudinal length into a narrow section and a wider section both being parallel to each other such that the bimetal plate is configured to control when and how a trip mechanism of a trip unit activates. The circuit breaker comprises a heating element coupled to the bimetal plate to heat the narrow section and the wider section when a current goes through the heating element. The narrow section and the wider section of the bimetal plate to deflect differently when a same amount of heat is applied in a same amount of time to control when and how the trip mechanism activates such that to allow to have two different current ratings in the frame in that the bimetal plate allows to increment a current protection level from a lower current rating to a higher current rating.

A circuit breaker having a frame comprises a bimetal plate having a longitudinal length wherein the bimetal plate is cut along the longitudinal length into a narrow section and a wider section both being parallel to each other such that the bimetal plate is configured to control when and how a trip mechanism of a trip unit activates. The circuit breaker comprises a heating element coupled to the bimetal plate to heat the narrow section and the wider section when a current goes through the heating element. The narrow section and the wider section of the bimetal plate to deflect differently when a same amount of heat is applied in a same amount of time to control when and how the trip mechanism activates such that to allow to have two different current ratings in the frame in that the bimetal plate allows to increment a current protection level from a lower current rating to a higher current rating.

A current assignment method and a switch arrangement are disclosed for assigning current, the switch arrangement including two series-connected switches, each including a trigger unit to check whether a preset current condition is satisfied. A signal is sent by the trigger unit of a switch which is postpositionally placed when the current condition is satisfied, the signal at least preventing the immediate triggering of a correspondingly prepositionally placed switch after being received by the corresponding trigger unit. To achieve a technically simple communication connection between switches, in at least one embodiment each trigger unit is formed so as to send but and receive the signal, and each trigger unit includes a measurement unit for measuring an energy flow direction in a subordinate switch and a conversion unit for converting from sending to receiving or from receiving to sending appropriately when the energy flow direction is reversed.

A method and an apparatus for controlling a circuit breaker in an electrical energy supply network. A switching signal is generated by a protective or control device of the energy supply network and the switching signal is transmitted to a control unit of the circuit breaker. The control unit is caused to open the switching contacts of the circuit breaker upon reception of the switching signal. In order to ensure a switching operation which is as fast as possible even in those energy supply networks in which phases of the current to be switched by a circuit breaker which are free of zero crossings can occur, a current flowing through the circuit breaker is recorded and is checked for the occurrence of zero crossings. The transmission of the signal for opening the switching contacts is prevented until at least one zero crossing has been detected.

A hybrid air-gap/solid-state device protection device (PD) for use in an electrical power distribution system includes an air-gap disconnect unit connected in series with a solid-state device, a sense and drive circuit, and a microcontroller. Upon the sense and drive circuit detecting an impending fault or exceedingly high and unacceptable overvoltage condition in the PD's load circuit, the sense and drive circuit generates a gating signal that quickly switches the solid-state device OFF. Meanwhile, the microcontroller generates a disconnect pulse for the air-gap disconnect unit, which responds by forming an air gap in the load circuit. Together, the switched-OFF solid-state device and air gap protect the load and associated load circuit from being damaged. They also serve to electrically and physically isolate the source of the fault or overload condition from the remainder of the electrical power distribution system.

Methods, apparatus, and systems are provided for a selectivity device for a circuit breaker. The invention includes a modular assembly adapted to be coupled to a load conductor assembly. The modular assembly includes a tripping plunger including a cam surface adapted to interact with a breaker tripping mechanism; an armature coupled to the tripping plunger; a yoke adapted to generate a magnetic field in response to an electric current in the load conductor assembly and disposed to apply a magnetic force proportionate to the electric current on the armature; and a spring assembly adapted to counter-balance the magnetic force up to a predefined tripping current in the load conductor assembly. Numerous additional aspects are disclosed.

The invention discloses a short circuit current hierarchical control tripping parameter circuit breaker. According to the invention, resistance of an alloy magnetic resistance body is changed through circuit current, and contract control can be carried out on short-circuit current. The control range of the circuit breaker can achieve that no magnetic resistance will be generated when current is no more than 8 times of rated operational current, and current limiting may be realized by the magnetic resistance when current is 8 times more than rated value. In this way, hierarchical control on short-circuit current of different levels of circuits can be carried out, and short-circuit current can be limited in a predetermined range, thereby restricting the short-circuit current in a predetermined range, solving a problem of power supply flickering, and avoiding large-area power failure accidents caused by override trip existing in an electrical control switch.

The invention discloses a short circuit current hierarchical control tripping parameter circuit breaker. According to the invention, resistance of an alloy magnetic resistance body is changed through circuit current, and contract control can be carried out on short-circuit current. The control range of the circuit breaker can achieve that no magnetic resistance will be generated when current is no more than 8 times of rated operational current, and current limiting may be realized by the magnetic resistance when current is 8 times more than rated value. In this way, hierarchical control on short-circuit current of different levels of circuits can be carried out, and short-circuit current can be limited in a predetermined range, thereby restricting the short-circuit current in a predetermined range, solving a problem of power supply flickering, and avoiding large-area power failure accidents caused by override trip existing in an electrical control switch.

An apparatus including one or more relays and a fault detector is disclosed. The one or more relays are coupled to a load. The fault detector is coupled with the one or more relays and receives at least one control signal. The fault detector includes a sensor to detect electricity flowing through the load and generate a detection signal. Based on a comparison of the control signal and the detection signal, the fault detector generates a fault signal indicative of whether a relay is functional or faulty.

An apparatus for detecting faults in devices, the apparatus comprising a first input for receiving a first control signal for controlling a switch, a first output for providing the first control signal to the switch, a sensor to detect a presence and an absence of electricity flowing through a load controlled by the switch to generate a detection signal, and circuitry configured to compare the detection signal and the first control signal and generate a fault signal indicating whether a fault is detected. When a logic level of the detection signal is the same as a logic level of the first control signal, the fault signal indicates that the fault is not detected. When the logic level of the detection signal is different from the logic level of the first control signal, the fault signal indicates that the fault is not detected.