A method of performing a circuit-breaking and closing operation in a three-phase system having a first phase, a second phase lagging the first phase by 120, and a third phase lagging the first phase by 240, includes: a) opening only one of the first phase, the second phase and the third phase before a zero crossing of a current of the corresponding phase, b) opening the remaining phases of the first phase, the second phase and the third phase after step a), and c) closing the first phase, the second phase and the third phase simultaneously or essentially simultaneously at a phase to ground voltage of the phase of the first phase, the second phase and the third phase which lagging the phase that was opened in step a) by 120 in a time range from 60 before a peak of the phase to 90 after the peak.

A method of performing a circuit-breaking and closing operation in a three-phase system having a first phase, a second phase lagging the first phase by 120, and a third phase lagging the first phase by 240, includes: a) opening only one of the first phase, the second phase and the third phase before a zero crossing of a current of the corresponding phase, b) opening the remaining phases of the first phase, the second phase and the third phase after step a), and c) closing the first phase, the second phase and the third phase simultaneously or essentially simultaneously at a phase to ground voltage of the phase of the first phase, the second phase and the third phase which lagging the phase that was opened in step a) by 120 in a time range from 60 before a peak of the phase to 90 after the peak.

The present invention discloses a dual-power overlapped closing operation mechanism, relating to the field of dual-power switches. The dual-power overlapped closing operation mechanism comprises a first contact, a second contact, a first connecting rod, a second connecting rod, a third connecting rod, a fourth connecting rod, a fifth connecting rod, a sixth connecting rod, a seventh connecting rod, a first auxiliary shaft, a second auxiliary shaft and a third auxiliary shaft. The fourth connecting rod rotates anticlockwise to push, via the fifth connecting rod and the seventh connecting rod, the second contact to make electrical contact with the second fixed contact, and at the same time the first contact is first tightly pressed via the second connecting rod and the third connecting rod until the dead point is passed, and then the first contact is gradually opened clockwise. The result of the fourth connecting rod rotating clockwise is similar, in which the second contact is first tightly pressed until the dead point is passed, and then the second contact is gradually opened clockwise. With the present invention, the neutral line overlapping has an extended duration and is maintained by means of a mechanical structure so as to effectively avoid the occurrence of a zero line break.

An automatic transfer switch assembly includes a first phase switch component, a second phase switch component and a third phase switch component arranged in order of the first phase switch component, the second phase switch component, and the third phase switch component in a line. The assembly further includes a first shield disposed between the first phase switch component and the second phase switch component, and a second shield disposed between the second phase switch component and the third phase switch component. Each of the first shield and the second shield includes a plurality of laminations of electrical steel.

The present invention discloses a dual-power overlapped closing operation mechanism, relating to the field of dual-power switches. The dual-power overlapped closing operation mechanism comprises a first contact, a second contact, a first connecting rod, a second connecting rod, a third connecting rod, a fourth connecting rod, a fifth connecting rod, a sixth connecting rod, a seventh connecting rod, a first auxiliary shaft, a second auxiliary shaft and a third auxiliary shaft. The fourth connecting rod rotates anticlockwise to push, via the fifth connecting rod and the seventh connecting rod, the second contact to make electrical contact with the second fixed contact, and at the same time the first contact is first tightly pressed via the second connecting rod and the third connecting rod until the dead point is passed, and then the first contact is gradually opened clockwise. The result of the fourth connecting rod rotating clockwise is similar, in which the second contact is first tightly pressed until the dead point is passed, and then the second contact is gradually opened clockwise. With the present invention, the neutral line overlapping has an extended duration and is maintained by means of a mechanical structure so as to effectively avoid the occurrence of a zero line break.

The present invention relates to a molded-case circuit breaker for direct current (DC), and more particularly, to a molded-case circuit breaker for DC that contains an internal connecting conductor connecting adjacent terminals to improve insulation performance and assemblability and reduce occupied space. There is provided a molded-case circuit breaker for DC that contains a plurality of interruption units within an outer casing, the DC circuit breaker including a two-unit connecting heater that connects fixed contacts of adjacent interruption units, the two-unit connecting heater being placed within the outer casing.

Embodiments of a disconnector and a switchgear, wherein the disconnector comprises a contact assembly operable to change a status of a circuit, the disconnector arranged in the circuit; shafts adapted to be driven to rotate to operate the contact assembly; and a transmission unit arranged between the shafts and comprising: a plurality of gears coupled to the shafts to enable the shafts to rotate with a mutual engagement of the plurality of gears; and a holding assembly adapted to hold radial positions of the plurality of gears to ensure the mutual engagement of the plurality of gears. By arranging the holding assembly to hold the radial positions of the gears to ensure the mutual engagement of the plurality of gears, only one input shaft and one transmission unit are enough to transmit large torques sufficient to operate the contact assembly.

An apparatus is disclosed comprising an interrupter and a first internal contact disposed within the interrupter; wherein an external terminal of the interrupter is configured for serving as a terminal in a switching mechanism; and wherein the first internal contact and the external terminal form opposite ends of a unitary conductive bar.

Switching device (1) for operating at least one load, comprising at least one switching unit (7; 8; 9), which switches a tapped current phase (L) to a load (2-1; 2-2; 2-3) connectable to the switching unit (7; 8; 9) to supply said load with current and which has a measurement unit (7C; 8C; 9C) which measures a current phase progression of the at least one current phase (L); a local control unit (18), which after receiving a control command from an external control system (24) actuates a semiconductor switch (7B; 8B; 9B) of the switching unit (7; 8; 9) in such a way that the semiconductor switch (7B; 8B; 9B) switches at a zero of the current phase (L) measured by the measurement unit (7C; 8C; 9C), and a local monitoring unit (20), which evaluates the current phase progression, measured by the measurement unit (7C; 8C; 9C), of the at least one current phase (L) to detect an operational deviation from a normal current supply to the associated load (2-1; 2-2; 2-3) connected to the switching unit (7; 8; 9), and reports any detected operational deviation.

An apparatus is disclosed comprising a vacuum interrupter; an upper insulating shield forming part of a support structure to mechanically support the vacuum interrupter in a mounted position; a top portion of the vacuum interrupter seated in the upper insulating shield; a first lower insulating shield forming part of the support structure to mechanically support the vacuum interrupter in a mounted position; and a lower portion of the vacuum interrupter seated in the first lower insulating shield, wherein the upper insulating shield and the lower insulating shield are mechanically coupled with one another independent of the vacuum interrupter.