An electrical metering system in a utility box is capable of receiving electrical signals received from a power utility company. The electrical metering system includes measurement circuitry capable of measuring properties of the received electrical signals. Based on the measurements, a determination is made that an arcing condition is present in the utility box. Based on the determination that the arcing condition is present, a disconnect circuit is activated to interrupt the connection between a source of the electrical signals and a premises.

An arc mitigation apparatus includes an arc mitigation device and a solar cell. The arc mitigation device is configured to be mounted to a low-, medium-, or high-voltage switchgear. The arc mitigation device is configured to stop or limit current flow within at least one part of the low-, medium-, or high-switchgear when activated. The solar-cell is configured to be located within a compartment of the low-, medium-, or high-voltage switchgear. The solar-cell is configured to cause the arc mitigation device to activate due to radiation from an electrical arc of the switchgear impinging upon the solar-cell.

A device for short-circuiting an electrical installation that includes at least two electrical conductors, the device including at least two connection terminals, each configured to be connected to a respective electrical conductor, an electromechanical unit configured to establish a short-circuit between the connection terminals, and at least one resistive element configured to connect one of the connection terminals to the corresponding electrical conductor. Each resistive element includes a first connection end connected to the corresponding connection terminal and a second connection end configured to be connected to the corresponding electrical conductor. The resistive element has an impedance, and variation in a value of the impedance is less than 1 m for a temperature of the resistive element of 0 C. to 200 C.

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.

An electrical installation includes: a switch cabinet; a protective switch arranged in the switch cabinet; and a cladding having electrical conductors and a voltage-measuring device/current-measuring device for measuring a current flowing through the electrical conductors, the voltage-measuring device/current-measuring device being operatively connected to the protective switch and being capable of triggering or switching off the protective switch when a measured value exceeding a threshold value is detected.

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.1 of the sensed light at a first wavelength 1 and a second intensity I.sub.2 of the sensed light at a second, greater wavelength 2. The ratio I.sub.1/I.sub.2 between the first intensity I.sub.1 and the second intensity I.sub.2 is determined. The sensed light is associated with an arc if said ratio I.sub.1/I.sub.2 is greater than a specifiable first threshold value and/or with a luminous gas at least containing metal vapor if said ratio I.sub.1/I.sub.2 is less than a specifiable second threshold value.

A computerized monitoring system and method for detecting electrical equipment failure. The system includes a sensor that detects a sound level representative of ultrasonic emissions radiating from electrical equipment to be monitored. A computer system in communication with the sensor is programmed to determine whether the electrical equipment is experiencing one or more of arcing, tracking, or corona based on the sound level detected by the sensor. In some embodiments, the computer system continuously monitors for these conditions based on the sound level detected by the sensor.

The invention relates to a device for detecting an electric arc based on an analog output signal (104) of at least one acoustic wave sensor (102), this device including: an analog-to-digital converter (106) capable of sampling and digitizing the output signal (104) of the sensor (102); a digital processing circuit (110) capable of implementing a frequency domain analysis of the digital output signal (108) of the converter (106) enabling to detect the possible presence of an arc based on its acoustic signature; and an analog circuit (118) for detecting the exceeding of a power threshold by the output signal (104) of the sensor (102), wherein the digital processing circuit (110) is configured to implement the frequency domain analysis only on detection of the exceeding of a threshold by the analog circuit (118).

A printing apparatus that has a plurality of functions including a printing function and is capable of executing printing with resolution of 300 dpi or more includes a plurality of operating units including a printing unit and a power supply unit. The power supply unit includes a substrate, an input terminal that receives an alternating voltage, a smoothing capacitor that smooths the alternating voltage, a thermistor that detects a temperature, and a comparator that compares a signal output from the thermistor with a standard signal and outputs a notification signal. The input terminal, the smoothing capacitor, the thermistor, and the comparator are mounted on the substrate. The supply of power from the power supply unit is stopped based on the state of the notification signal. A gap between the input terminal and the thermistor is longer than a gap between the input terminal and the smoothing capacitor.

The present invention relates to a method for operating a security device, comprising a housing with at least one current-carrying element, wherein the current-carrying element is arranged in the housing interior and is enclosed by the housing. A particle detector is arranged in the housing interior, which monitors the housing interior with respect to the formation of particles.