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.

This limiter pole (B) for a multipole DC electrical switch (2) comprises a compartment in which an input terminal and an output terminal for a direct electric current are provided, along with a first electrical contact connected to the input terminal and a second electrical contact connected to the output terminal, third and fourth electrical contacts connected to one another in series, the third and fourth contacts being capable of being moved simultaneously relative to the first and second electrical contacts, respectively, between a closed position, in which the first and third contacts and the second and fourth contacts make contact with one another so as to allow the direct electric current to flow between the input terminal and the output terminal, and an open position, in which said contacts are located away from one another, interrupting the flow of the current between the input terminal and the output terminal. The limiter pole (B) comprises a first electric arc formation chamber in which the first and third electrical contacts are placed, a second electric arc formation chamber in which the second and fourth electrical contacts are placed, and first and second electric arc extinguishing chambers which are associated with the first and second electric arc formation chambers, respectively.

This disclosure relates generally to power isolation switch devices. In one embodiment, a power isolation switch device has a power insulator, an arc breaker, and a switch. The power insulator and the switch are connected in parallel. The arc contact is operably associated with the switch such that the arc contact is removed from the arc chute as the switch is opened and is inserted to contact the arc chute when the switch is closed. In this manner, the power isolation switch device does not need an interrupter and can be provided so as to be less bulky.

A network service and transformer safety protector on a secondary side of a network transformer tank system. The network service and transformer safety protector is positioned between the network transformer and a secondary network distribution system and is configured to connect and disconnect a transformer from the secondary network. The network service and transformer safety protector is attached to the outside of the transformer tank.

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 trigger element includes an actuating member of a pressure trigger for an electric switch. The pressure trigger is provided with at least one flow channel per electric pole. The at least one pole of the electric switch includes at least two switch contacts for making or breaking a current path. The switch contacts of the at least one pole of the electric switch is disconnectable via the actuating member, which can respond to a pressure that is generated by an electric arc drawn during electrodynamic recoil of the switch contacts in a separation zone of the two switch contacts. The separation zone is connectable to the actuating member via the flow channel such that the actuating member is guided from a housing of the trigger element between a neutral position and a trigger position. After the trigger position has been reached, a relief of pressure vents the pressure trigger.

The invention refers to a circuit breaker (300A) comprising a vacuum interrupter (301) for a gas insulated switchgear. Moreover, the invention refers to a gas insulated switchgear comprising at least one circuit breaker (300A) and/or a disconnector pole. The circuit breaker (300A) has a vacuum interrupter (301) comprising a first movable contact (302), a second stationary contact (303) and a first center axis (304). Moreover, the circuit breaker (300A) comprises a first insulator (305), a contact unit (306) arranged at the first insulator (305), wherein the first movable contact (302) can be moved towards the contact unit (306) so as to be connected to the contact unit (306), an electrical conducting unit (307) comprising a first side (308) and a second side (309), wherein the first side (308) and the second side (309) are opposite to each other, wherein the vacuum interrupter (301) is arranged at the first side (308) of the electrical conducting unit (307), and a second insulator (310) wherein the second insulator (310) is arranged at the second side (309) of the electrical conducting unit (307), wherein the second insulator (310) is connected to the second stationary contact (303), wherein the second insulator (310) has a second center axis (311), and wherein the second center axis (311) of the second insulator (310) is parallel to or collinear with the first center axis (304) of the vacuum interrupter (301).

A low-voltage multipolar circuit breaker includes a moulded housing including a main body that is divided into interior compartments, each associated with one pole of the circuit breaker, and a cover that is mounted on the main body covering a main face of the body. The circuit breaker includes, for each pole, electrical contacts that can be separated by a device of a switching mechanism and an arc-extinguishing chamber. For at least two of the poles, the main face includes an additional aperture, each placed directly above the spark guard of the corresponding pole and placing the arc-extinguishing chamber of this pole in communication with the interior volume delimited by the cover and the main face, and the cover is attached to the main body while leaving a peripheral opening between the cover and the main body, placing the interior volume in communication with the exterior of the housing.

This electric switch comprises an arc-blasting unit with a compression cylinder (25) enclosing a compression chamber (27) mobile together with the mobile contacts (2), and a stationary piston (13) at an end of the compression chamber, provided with a support rod made up as a blowpipe (9) which channels the gas compressed in the chamber when the contacts separate to a nozzle (10) that directs the flow to a separation place (12) of the contacts so as to efficiently blast electric arcs. The arrangement is lightweight and occupies little space.

A switching device arrangement has an encapsulation housing and also a drive device. The drive device is supported on the encapsulation housing. The drive device is arranged at a distance from the encapsulation housing via a spacer device. A receiving space is delimited by the spacer device.