A method and system are provided to control circuit breaker operations. In the method and system, near-field RF signal is monitored at or around electrical contacts of the circuit breaker using at least one near-field radio frequency (RF) sensor, and far-field RF signal away from the contacts of the circuit breaker are monitored using at least one far-field RF sensor. A rate of change of current over time is also monitored on the circuit using at least one sensor. An arc fault on the circuit is detected based on the monitored near-field RF signal, the monitored far-field RF signal, and the monitored rate of change of current. A tripping operation is implemented on the circuit breaker to disconnect the power supply from the circuit, in response to the detection of the arc fault.

A method for determining phase locking of critical arc light includes: step 1: monitoring and collecting light radiation intensity of an arc inside a switch cabinet in real time, and converting the collected light radiation intensity into an electrical signal; step 2: extracting a power-frequency fundamental wave of the electrical signal, comparing an amplitude of the power-frequency fundamental wave of the electrical signal with a first threshold, and generating a pre-warning signal based on a comparison result of the first threshold; step 3: comparing the amplitude of the power-frequency fundamental wave of the electrical signal with a second threshold voltage, and generating a control signal based on a comparison result of the second threshold voltage and a protection time threshold; and step 4: protecting the switch cabinet under the critical arc light environment based on the pre-warning signal and the control signal.

A method and a system for the detection and passivation of an electric arc on at least one connecting element of an electrical device. The system comprises an acoustic acquisition channel configured for the acquisition of acoustic signals emitted by the connecting element, an electric acquisition channel configured for the acquisition of electric signals which are representative of the electric current intensities supplying the connecting element, and a correlator coupled to the acoustic and electric acquisition channels, configured for the evaluation of a correlation between the acoustic and electric signals and for the tripping of an appropriate cut-off signal for the interruption of an electric circuit relative to the connecting element, where the correlation is representative of the initiation of an electric arc.

Systems and methods for tripping open circuit interrupters based on the detection of an arc flash using an accessory arc flash detection module are disclosed. The housing of the arc flash detection module is structured to be installed within the frame of a circuit interrupter. The detection module communicates with light sensors structured to detect light from arc flash events, and includes a controller configured to communicate with an electronic trip unit of the circuit interrupter. In one embodiment, the detection module is configured to alert the electronic trip unit that light indicative of arc flash conditions has been detected such that the electronic trip unit can determine whether or not to initiate a trip after determining the magnitude of current flowing through the circuit interrupter. In another embodiment, the detection module is configured to directly actuate a trip of the circuit interrupter based on the detection of light.

A system including ruggedized optic fiber cable assembly for use with an arc detection relay to protect electrical components from faults resulting in an arc flash. The cable assembly includes a pair of ruggedized ST connectors located at opposite ends of a ruggedized optical fiber cable. The cable includes an optical fiber core surrounded by a transparent gel layer and a transparent jacket surrounding the gel layer. Each ST connector includes a boot formed of a resilient material to provide shock absorption for the portion of the optical fiber cable extending through it. An accessory electronic cable is also provided, as are couplers, adapters for mounting the couplers onto walls, and sleeves with air pockets to enhance the ruggedness of the cable at points of stress, e.g., bends.

An electrical system includes first, second and third busses; a first interrupter electrically connected between the first and second busses; at least one of a shorting apparatus operatively associated with the first or second bus, and the first interrupter comprising a trip coil; a current sensor to sense a fault current flowing in the first bus and responsively output a first signal; a number of light sensors to sense an arc flash operatively associated with a number of the first, second or third busses and responsively output a second signal; a second interrupter electrically connected between the second and third power busses and output a third signal; and a circuit to invert the third signal to provide a fourth signal, and to operate the at least one of the shorting apparatus and the trip coil responsive to an AND of the first, second and fourth signals.

A method for distinguishing an arc from a luminous gas at least containing metal vapor includes sensing light in a monitoring region and determining a first intensity I.sub.λ1 of the sensed light at a first wavelength λ1 and a second intensity I.sub.λ2 of the sensed light at a second, greater wavelength λ2. The ratio I.sub.λ1/I.sub.λ2 between the first intensity I.sub.λ1 and the second intensity I.sub.λ2 is determined. The sensed light is associated with an arc if said ratio I.sub.λ1/I.sub.λ2 is greater than a specifiable first threshold value and/or with a luminous gas at least containing metal vapor if said ratio I.sub.λ1/I.sub.λ2 is less than a specifiable second threshold value.

A circuit breaker with a switching path has at least one line interruption apparatus, wherein the circuit breaker has a disconnection unit and a connection unit which are each connected to the line interruption apparatus. The switching device has at least one measuring arrangement for measuring at least one electrical variable on the at least one switching path. The disconnection unit further has a comparison and decision unit, which comparison and decision unit is connected to the measuring arrangement and to the line interruption apparatus. The circuit breaker has a first data interface, which first data interface is designed to receive at least one connection command and/or one disconnection command, and wherein the first data interface is connected to the disconnection unit and the connection unit.

A system for protection from fires and electrical shock of components used in construction of electrical systems is disclosed using a sensing degree of characteristic before an arc fault, with the purpose to detect, annunciate, and remove the hazard before an electrical arc occurs.

A short circuit current detection device for a medium voltage or high voltage switchgear includes: a reed contact; and a holder for holding the reed contact, the holder being mountable with a defined orientation to a conductor of the switchgear. At a location where the holder is mounted, the conductor has a longitudinal axis. The conductor enables a current to flow through the conductor in a direction of the longitudinal axis. The holder positions the reed contact with respect to the longitudinal axis such that when a magnitude of the current flow through the conductor exceeds a threshold current value the reed contact closes.