An electrical switching apparatus assembly is for a switchgear system. The switchgear system includes a number of circuit stabs and an enclosure having a number of compartments. The electrical switching apparatus assembly includes an electrical switching apparatus having a number of terminals and a mounting assembly, the terminals being structured to be mechanically coupled and electrically connected to the circuit stabs, the mounting assembly comprising a mounting member coupled to the terminals; and a maintaining assembly comprising a plate member and a maintaining member, the plate member being coupled to the mounting member, the maintaining member being coupled to the plate member and structured to engage the enclosure. Responsive to an arc fault event, the maintaining assembly is structured to move between FIRST and SECOND positions. When the maintaining assembly moves from the FIRST position to the SECOND position, the plate member moves away from the terminals.

A switching device includes: a first contact; a second contact; and a fault detection circuit. The second contact includes a fixed contactor and a movable contactor. When the second contact is energized due to an operation of opening the first contact, the movable contact is separated from the fixed contact by an electromagnetic force generated by a flow of currents in opposite directions through the pair of current-carrying electrodes, and a discharge switch is formed between the movable contact and the fixed contact that are separated. The switching device further includes: a first arc runner electrically connected to the fixed contactor for driving, by an electromagnetic force, arc discharge that occurs when the second contact is opened; and a second arc runner electrically connected to the movable contactor.

A switching device includes: a first contact; a second contact; and a fault detection circuit. The second contact includes a fixed contactor and a movable contactor. When the second contact is energized due to an operation of opening the first contact, the movable contact is separated from the fixed contact by an electromagnetic force generated by a flow of currents in opposite directions through the pair of current-carrying electrodes, and a discharge switch is formed between the movable contact and the fixed contact that are separated. The switching device further includes: a first arc runner electrically connected to the fixed contactor for driving, by an electromagnetic force, arc discharge that occurs when the second contact is opened; and a second arc runner electrically connected to the movable contactor.

An electrical switching apparatus assembly is for a switchgear system. The switchgear system includes a number of circuit stabs and an enclosure having a number of compartments. The electrical switching apparatus assembly includes an electrical switching apparatus having a number of terminals and a mounting assembly, the terminals being structured to be mechanically coupled and electrically connected to the circuit stabs, the mounting assembly comprising a mounting member coupled to the terminals; and a maintaining assembly comprising a plate member and a maintaining member, the plate member being coupled to the mounting member, the maintaining member being coupled to the plate member and structured to engage the enclosure. Responsive to an arc fault event, the maintaining assembly is structured to move between FIRST and SECOND positions. When the maintaining assembly moves from the FIRST position to the SECOND position, the plate member moves away from the terminals.

A method and a circuit for detecting an electric arc in an electric circuit supplied with AC current during a supply period includes measuring at least one input signal (S) among a current (I) and an input voltage (U) of the electric circuit, supplying a warning signal (A1) to indicate that an electric arc occurs when the input signal (S) is constant over at least one portion of the supply period, digitally sampling the input signal (S) during the measurement thereof according to predetermined levels and, to identify that the input signal (S) is constant, determining the frequency at which each level is reached by the input signal (S) over a predetermined time window, comparing the frequency of each level with a predetermined warning threshold, and issuing the warning signal if the frequency of at least one of the levels is higher than the warning threshold.

A method and a circuit for detecting an electric arc in an electric circuit supplied with AC current during a supply period includes measuring at least one input signal (S) among a current (I) and an input voltage (U) of the electric circuit, supplying a warning signal (A1) to indicate that an electric arc occurs when the input signal (S) is constant over at least one portion of the supply period, digitally sampling the input signal (S) during the measurement thereof according to predetermined levels and, to identify that the input signal (S) is constant, determining the frequency at which each level is reached by the input signal (S) over a predetermined time window, comparing the frequency of each level with a predetermined warning threshold, and issuing the warning signal if the frequency of at least one of the levels is higher than the warning threshold.

A vacuum monitoring device of a vacuum circuit breaker with a line of a vacuum valve led out to the external of a metal tank through a bushing having a shield working as a low-pass filter, includes: a first antenna; a second antenna; a first and a second detection portion measuring intensity of an electromagnetic wave detected by the antennas; and a determination portion determining a vacuum deterioration of the circuit breaker by comparing the intensity of the electromagnetic wave detected by the first and the second detection portions, wherein the first and second detection portion include frequency filters passing a frequency band, of electromagnetic waves resulting from discharges occurring when the vacuum valve deteriorates in vacuum, which is attenuated by the shield.

A vacuum monitoring device of a vacuum circuit breaker with a line of a vacuum valve led out to the external of a metal tank through a bushing having a shield working as a low-pass filter, includes: a first antenna; a second antenna; a first and a second detection portion measuring intensity of an electromagnetic wave detected by the antennas; and a determination portion determining a vacuum deterioration of the circuit breaker by comparing the intensity of the electromagnetic wave detected by the first and the second detection portions, wherein the first and second detection portion include frequency filters passing a frequency band, of electromagnetic waves resulting from discharges occurring when the vacuum valve deteriorates in vacuum, which is attenuated by the shield.

A high voltage DC contactor control system. The system reduces/eliminates arcing in in contactors and includes a short circuit protection system operably connected to the drive voltage configured to reducing arcing between portions of the contactor. The short circuit protection system includes a first arc prevention element and a first arc prevention driver configured to cause the first arc prevention element to be disposed between the first and second portions of the first contactor to prevent arcing between them.

A high voltage DC contactor control system. The system reduces/eliminates arcing in in contactors and includes a short circuit protection system operably connected to the drive voltage configured to reducing arcing between portions of the contactor. The short circuit protection system includes a first arc prevention element and a first arc prevention driver configured to cause the first arc prevention element to be disposed between the first and second portions of the first contactor to prevent arcing between them.