A knife switch device for use in a switchgear or a ring main unit, the knife switch device including a stationary contact member, and a movable contact member, the movable contact member being rotatable about a main revolute joint for selectively opening and closing the knife switch device, the movable contact member including at least a first segment and a second segment, the first segment and the second segment being coupled by an auxiliary revolute joint, wherein the main revolute joint is arranged on the second segment, and wherein a rotation axis of the main revolute joint is substantially parallel to a rotation axis of the auxiliary revolute joint.

A knife switch device for use in a switchgear or a ring main unit, the knife switch device including a stationary contact member, and a movable contact member, the movable contact member being rotatable about a main revolute joint for selectively opening and closing the knife switch device, the movable contact member including at least a first segment and a second segment, the first segment and the second segment being coupled by an auxiliary revolute joint, wherein the main revolute joint is arranged on the second segment, and wherein a rotation axis of the main revolute joint is substantially parallel to a rotation axis of the auxiliary revolute joint.

A high voltage air disconnect switch having an electrical load interrupter unit responsive to the opening of the high voltage air break disconnect switch. The electrical load interrupter unit including an actuating arm is contacted, during the opening of the switch, by a moving arc horn attached to and in electrical circuit with a switch blade of the high voltage air disconnect switch. The moving arc horn has operatively attached a spring catch which engages the actuating arm with a physical holding force applied to an electric contact point between the actuating arm and the moving arc horn to firmly capture the interrupter actuating arm against the moving arc horn during opening of the switch to prevent any arc burning damage due to arcing between the actuating arm and the moving arc horn as the switch opens.

A high voltage air disconnect switch having an electrical load interrupter unit responsive to the opening of the high voltage air break disconnect switch. The electrical load interrupter unit including an actuating arm is contacted, during the opening of the switch, by a moving arc horn attached to and in electrical circuit with a switch blade of the high voltage air disconnect switch. The moving arc horn has operatively attached a spring catch which engages the actuating arm with a physical holding force applied to an electric contact point between the actuating arm and the moving arc horn to firmly capture the interrupter actuating arm against the moving arc horn during opening of the switch to prevent any arc burning damage due to arcing between the actuating arm and the moving arc horn as the switch opens.

A high voltage disconnection unit includes a fixed contact assembly having at least a first fixed main contact and a first fixed auxiliary contact, a movable contact assembly having at least a first movable main contact and a first movable auxiliary contact that rotate with respect to the first fixed main contact and first fixed auxiliary contact from a contacts closed position to a contacts open position. During an opening operation of the disconnection unit the separation of the first movable main contact from the first fixed main contact takes place before the separation of the first movable auxiliary contact from the first fixed auxiliary contact. The relative opening speed V1 between the first movable auxiliary contact and the first fixed auxiliary contact is greater than the relative opening speed V2 between the first movable main contact and the first fixed main contact.

A high voltage disconnection unit includes a fixed contact assembly having at least a first fixed main contact and a first fixed auxiliary contact, a movable contact assembly having at least a first movable main contact and a first movable auxiliary contact that rotate with respect to the first fixed main contact and first fixed auxiliary contact from a contacts closed position to a contacts open position. During an opening operation of the disconnection unit the separation of the first movable main contact from the first fixed main contact takes place before the separation of the first movable auxiliary contact from the first fixed auxiliary contact. The relative opening speed V1 between the first movable auxiliary contact and the first fixed auxiliary contact is greater than the relative opening speed V2 between the first movable main contact and the first fixed main contact.

Systems of automatic transfer switches (ATS) are disclosed herein. One apparatus includes at least two automatic transfer switches coupled together. Each automatic transfer switches has contacts to couple a power source to a load. For each switch, an electromagnetic force biasing the contacts to each other is present if an electrical current flows through the switch. The automatic transfer switches may be on separate cassettes or on a single cassette. The power source of each switch may be the same or different.

A disconnector having a stack of modular contact boxes surmounted by a snap-action switch box, each modular contact box including a rotary contact and two fixed contacts which are accessible from the outside. The switch box further includes a driven indexing element which is rotatably associated with a spindle loading support and at least one spring connected between the two in order to load them elastically with respect to each other following a mutual rotation about the central axis. The disconnector has a single actuation rod which passes through all the modular contact boxes coaxially to the central axis and is fixed in rotation to all the rotary contacts.

An automatic transfer switch includes a first conduction bar selectively coupled with a first power source and a load conduction bar; a second conduction bar selectively coupled with a second power source and the load conduction bar; a first blade assembly electrically coupled to the first conduction bar; and a second blade assembly electrically coupled to the second conduction bar. The first blade assembly is electrically coupled to a first source conduction bar in a closed position, and a first electromagnetic force induced by a first current flowing through the first blade assembly and the first conduction bar repulses the first blade assembly. The second blade assembly is electrically coupled to a second source conduction bar in a closed position, and a second electromagnetic force induced by a second current flowing through the second blade assembly and the second conduction bar repulses the second blade assembly.

An automatic transfer switch includes a first conduction bar selectively coupled with a first power source and a load conduction bar; a second conduction bar selectively coupled with a second power source and the load conduction bar; a first blade assembly electrically coupled to the first conduction bar; and a second blade assembly electrically coupled to the second conduction bar. The first blade assembly is electrically coupled to a first source conduction bar in a closed position, and a first electromagnetic force induced by a first current flowing through the first blade assembly and the first conduction bar repulses the first blade assembly. The second blade assembly is electrically coupled to a second source conduction bar in a closed position, and a second electromagnetic force induced by a second current flowing through the second blade assembly and the second conduction bar repulses the second blade assembly.