354 results about "Surge arrester" patented technology

In one embodiment, a device for coupling communications signals onto a medium-voltage power line includes a first connector, a second connector and one or more components. The first connector is adapted to couple to a low-voltage communications line. The second connector is adapted to couple to a surge arrester. The one or more components are operable to substantially match the impedances between the surge arrester and the low-voltage communications line.

The application describes an electrical terminal comprising a pair of longitudinally disposed contact members, each having a pair of insulation displacement connectors connectors, one at either end thereof, thereby to link two wire pairs, wherein. each contact member comprises a contact arm each extending in a defined direction, the contact arms leading to a pair of arrestor contacts spaced so as to accept a surge arrestor. The defined direction is preferably substantially transverse to the contact members. This enables the surge arrestor to be placed to one side of the electrical terminal, avoiding interference with ingoing and outgoing wires and avoiding inhibiting access to test points. The contact members are preferably parallel within the electrical terminal. The arrestor contacts are preferably spring contacts, thereby to enable replacement of the arrestor. The contact arms more preferably end at the spring contacts. In a particularly preferred embodiment, the contact arms are non-contiguous with the contact members but are joined thereto. This join can be by way of a lug extending from the edge of one of the two members and engaging within a slot of the other. This provides a particularly simple but effective electrical contact. The lug is preferably on the contact members, thereby placing the slot on the contact arms. This also avoids the need to bend a single-piece blank, thereby risking damage to or distribution of the IDC connector. The terminal will ideally be enclosed within a plastic housing, and this will preferably comprise a recess for receiving the surge arrestor, the arrestor contacts extending into the recess.

A device for breaking DC currents exceeding 2500 A has a resonance circuit (2) connected in parallel with an interrupter (1) and a surge arrester (7) connected in parallel with the resonance circuit. The resonance circuit has a series connection of a capacitor (3) and an inductance (4). The specific value relationship of the capacitance in microfarad to the inductance in microhenry of the resonance circuit is not less than 1.

An apparatus for sensing and measuring the HV surge arrester current includes two toroidal current transformers arranged coaxially with respect to the earth wire of the surge arrester, elements for sensing the current signals emitted by the transformers and for converting the current signals in digital signals, and elements for transmitting the digital signals to an information network and analog state signals by relay activation. The two toroidal current instrument transformers are associated, respectively, one to elements for sensing the normal leakage current, and the other to elements for sensing the impulsive current, the latter comprising a circuit (TRIGGER) discriminating between “switching” and “lightning” signals, in which the basis for discrimination is a signal duration threshold, of about 35 μs.