A device for measuring a condition of an electric switch, an electric switch and a method for measuring a condition of an electric switch are disclosed. In an embodiment an apparatus for measuring a state of an electrical switch is configured to tap a voltage at main contacts of the electrical switch.

A HVDC disconnector is disclosed. The HVDC disconnector comprises a fixed contact comprising a guide and a pair of conducting members positioned in the guide wherein the first and second conducting members are both tulip contacts; a movable contact comprising a fixed arm and a mobile arm having a conducting terminal, wherein the mobile arm is movable from an open position to a closed position to close a connection between the fixed contact and the second contact.

A novel magnetic switch, comprising a housing, a terminal A and a terminal B, wherein an inner cavity of the housing is internally provided with a magnetic body and a tongue plate, one end of the tongue plate is movably connected to the upper end of the terminal B, the magnetic body, which is integrally linked to the tongue plate, is capable of being raised thereon; the other end of the tongue plate is disposed above the terminal A; the upper end of the terminal A is provided with an arc-removing apparatus, the arc-removing apparatus is provided with a stationary contact, and the other end of the tongue plate is provided with a movable contact. The magnetic switch has an effective structure, thus improving the work stability and prolonging the service life of the switch.

A high voltage DC circuit interrupter that is provided with a double break contact where each contact is provided with an arc chamber. The double break contacts are provided in series with each other and an overcurrent measurement device such that if an overcurrent is measured, the contacts are simultaneously opened (i.e., double break) to lower the voltage that is developed across each of the sets of contacts. A handle is provided for simultaneously resetting and closing the sets of contacts.

A contact assembly for connecting electrically and mechanically a first terminal of a first apparatus to a second terminal of a second apparatus, wherein at least one of the first and the second apparatus is movable with respect to the other along a connection/disconnection direction, includes: a plurality of electrically conducting contact-finger-elements, each including a main contact portion configured for engaging the second terminal and an auxiliary contact portion for engaging the first terminal, wherein the finger-contact-elements are supported by a support frame of the contact assembly connectable to the first terminal or are configured for being directly connectable and supportable by the first terminal; one or more spring elements configured for acting on the contact-finger-elements so to urge the main contact portions against the second terminal when the first and the second apparatus are connected. The main contact portions of at least two of the plurality of contact-finger-elements are shifted one relative to the other in such a manner so to engage the second terminal in subsequent moments when the first apparatus is being connected to the second apparatus by a relative movement thereof along the connection/disconnection direction.

Device for making and/or breaking a current including a pair of permanent contacts (3, 4), at least one of the contacts (3, 4) being movable. At least one permanent contact (3, 4) including a main portion (3.1, 4.1) having a free end and an end protection portion (3.2, 4.2) secured to the free end of the main portion (3.1, 4.1), designed to be in mechanical and electrical contact with the other permanent contact (4, 3) only during an operation for opening or closing the pair. The end protection portion (3.2, 4.2) is made of a single transition metal having a melting temperature that is strictly higher than that of the main portion (3.1, 4.1) to which it is secured, or of an oxide or carbide of such a metal, or even of zinc oxide. For application in particular to high- or medium-voltage circuit breakers.

A circuit breaker includes a frame having an interior compartment and an outer surface and a bushing opening. A circuit interrupter is mounted within the interior compartment. A terminal bushing is received within the bushing opening and has a lower terminal end extending into the housing and electrically connected to the circuit interrupter. An outer flange forms a bushing seat positioned adjacent the outer surface. An upper gasket is received against the outer flange. A seal pocket is formed by a bushing opening, upper gasket and outer surface of the terminal bushing. A dynamic seal is contained within the seal pocket and compressed an amount sufficient to provide elasticity and a compression height for dynamic loading of the upper gasket.

Switchgear comprises a support structure that supports one or more bus conductors. The bus conductor(s) each extend longitudinally in a bus direction. The switchgear further includes one or more circuit breaker bays. Each circuit breaker bay comprises feeder cable terminal(s) configured to respectively terminate feeder cable(s). Each circuit breaker bay further comprises a circuit breaker that is spaced from the feeder cable terminal(s) in the bus direction, and that comprises terminal pair(s). Each pair includes a bus-side terminal via which the circuit breaker connects to a respective bus conductor and a feeder-side terminal via which the circuit breaker connects to a respective feeder cable terminal. The circuit breaker is also configured to selectively interrupt current between the bus-side terminal and the feeder-side terminal of each terminal pair. The bus-side terminal and the feeder-side terminal of each terminal pair are spaced from one another in the bus direction.

The present disclosure relates a terminal assembly for a vacuum contactor switch which is connected to a terminal of a cradle with electricity applicability to protect a power system by breaking circuits in the event of a dangerous situation such as a short circuit or an overcurrent. The terminal assembly includes a body portion, a connecting member, a contactor and a bush. The body portion is inserted into a terminal hole formed in the terminal of the cradle and provided with first fastening holes formed in opposite side surface thereof. The contactor is connected to one end of the body portion through a connecting member. The bush has a pair of pieces disposed to surround a periphery of the body portion with both ends of one of the pieces facing both ends of the other piece.

An alternative gas current pause circuit interrupter with an internally switched resistor-varistor impedance. The varistor limits the voltage rise across the main contactor limiting restrikes, while the resistor limits the current through the interrupter. The values of the resistor and varistor are selected to creates a current pause in the current. In a representative embodiment, the current pause performance is less than 10% of the rated line current for at least 15% of the half-cycle period allowing a plain break butt impedance contactor to be utilized without excessive arcing. For another embodiment the current pause performance is less than 5% of the rated line current for at least 20% of the half-cycle period. SF6 free alternative gas current pause circuit interrupters using a 60% CO2 blend can achieve similar or improved transient voltage performance compared to similarly sized conventional SF6 gas interrupters operating at the same voltage rating.