This present application concerns a method for preventing an electrical grid from a failure in case of a temporary overvoltage. A method comprising: a) providing an electrical grid line, a surge arrester and a disconnector device with a disconnector unit; b) connecting the surge arrester at one terminal to the electrical grid line; c) connecting the surge arrester at its other terminal to a second terminal of the disconnector device; d) connecting a first terminal of the disconnector device to ground potential; e) interrupting the electrical connection in between the electrical grid line and the ground potential in case of a temporary overvoltage; f) protecting the surge arrester from failure due to a thermal overload caused by the temporary overvoltages by operating the disconnector device before the surge arrester fails due to a thermal overload of the surge arrester.

This present application concerns a method for preventing an electrical grid from a failure in case of a temporary overvoltage. A method comprising: a) providing an electrical grid line, a surge arrester and a disconnector device with a disconnector unit; b) connecting the surge arrester at one terminal to the electrical grid line; c) connecting the surge arrester at its other terminal to a second terminal of the disconnector device; d) connecting a first terminal of the disconnector device to ground potential; e) interrupting the electrical connection in between the electrical grid line and the ground potential in case of a temporary overvoltage; f) protecting the surge arrester from failure due to a thermal overload caused by the temporary overvoltages by operating the disconnector device before the surge arrester fails due to a thermal overload of the surge arrester.

An externally gapped line arrester, EGLA, for transmission lines, the EGLA including a series varistor unit, SVU, having a first end and a second end, the SVU configured to be connected between a transmission line and ground, a primary sparkover gap unit serially connected to the first end of the SVU, a secondary gap arranged between the second end of the SVU and ground, and the secondary gap serially connected to the second end of the SVU, a shorting-link device connected in parallel with the secondary gap, and a disconnecting device arranged in the shorting-link device, the disconnecting device configured to open the shorting-link device when the SVU is overloaded. A method for impulse protection performed by an EGLA is also disclosed.

The invention relates to a lightning protection spark gap assembly. The lightning protection spark gap assembly comprises: a lightning protection spark gap (1); a safety fuse device (8) which can be triggered by a bridge initiator (7) and which is connected between a first or second voltage line (S1, S2) and a corresponding main connection (1, 1b) of the lighting protection spark gap (1); and an indicator device (4′) for detecting a secondary current flow connecting to a pulse current flow or a corresponding portion of the secondary current flow, and for triggering the safety fuse device (8) by activating the bridge initiator (7) when the detected secondary current flow or the corresponding portion of the secondary current flow fulfills a first predefined criterion, wherein the lightning protection spark gap (1) has a first and a second divergent electrode (21a, 21b) and an arcing chamber (25), and wherein the indicator device (4′) is electrically connected to the first or second divergent electrode (21a, 21b) and/or the arcing chamber (25) in such a way that it detects the secondary current flow or the corresponding portion of the secondary current flow in the area (L) in which the secondary current arc flows.

The invention relates to a lightning protection spark gap assembly. The lightning protection spark gap assembly comprises: a lightning protection spark gap (1); a safety fuse device (8) which can be triggered by a bridge initiator (7) and which is connected between a first or second voltage line (S1, S2) and a corresponding main connection (1, 1b) of the lighting protection spark gap (1); and an indicator device (4′) for detecting a secondary current flow connecting to a pulse current flow or a corresponding portion of the secondary current flow, and for triggering the safety fuse device (8) by activating the bridge initiator (7) when the detected secondary current flow or the corresponding portion of the secondary current flow fulfills a first predefined criterion, wherein the lightning protection spark gap (1) has a first and a second divergent electrode (21a, 21b) and an arcing chamber (25), and wherein the indicator device (4′) is electrically connected to the first or second divergent electrode (21a, 21b) and/or the arcing chamber (25) in such a way that it detects the secondary current flow or the corresponding portion of the secondary current flow in the area (L) in which the secondary current arc flows.

An electrical fuse assembly includes a housing defining a hermetically sealed chamber, first and second terminal electrodes mounted on the housing, a gas contained in the hermetically sealed chamber, a fuse element electrically connecting the first and second terminal electrodes, and at least one spark gap between the first and second terminal electrodes. The fuse element and the at least one spark gap are disposed in the hermetically sealed chamber.

An interrupter device provides overload protection. The device includes a first terminal that is configured to establish an electrical connection to a first terminal of a high voltage surge arrester, a second terminal that is configured to establish an electrical connection to an electrical power grid line side conductor, and a chargeless disconnection trigger that causes an interruption in an electrically conductive path between the first and second terminal in response to an overload condition at the second terminal.

The invention relates to an overvoltage protection arrangement comprising a horn spark gap located in an insulating housing, with a deionization chamber for arc quenching, wherein the deionization chamber has a plurality of spaced quench plates and a trigger electrode is located in the ignition region of the horn spark gap, wherein a disconnecting device comprises a fusible link that is located in the region of the deionization chamber and is exposed there to a loading of a power follow-on current, wherein the fusible link holds a disconnecting element, preferably supported by spring force, in a first position, and on melting releases this disconnecting element in such a way that the disconnecting element adopts a second position wherein, on reaching the second position, an electrical connection to the trigger electrode is interrupted and the trigger electrode is thereby disconnected.

The invention relates to an overvoltage protection arrangement comprising a horn spark gap located in an insulating housing, with a deionization chamber for arc quenching, wherein the deionization chamber has a plurality of spaced quench plates and a trigger electrode is located in the ignition region of the horn spark gap, wherein a disconnecting device comprises a fusible link that is located in the region of the deionization chamber and is exposed there to a loading of a power follow-on current, wherein the fusible link holds a disconnecting element, preferably supported by spring force, in a first position, and on melting releases this disconnecting element in such a way that the disconnecting element adopts a second position wherein, on reaching the second position, an electrical connection to the trigger electrode is interrupted and the trigger electrode is thereby disconnected.

A multi-spark gap having both a high power-follow current extinguishing capacity as well as a relatively low protective level in which a distance x.sub.1 between a first electrode and an adjacent second electrode, which together form a first individual spark gap, is larger than respective distances x.sub.2 between other adjacent electrode pairs of additional individual spark gaps. The distance x1 is at least 0.5 mm and the distances x2 of the additional individual spark gaps are at most 0.2 mm. Additionally, an ignition aid for igniting the first individual spark gap is provided, which aid has at least a resistive ignition element and a voltage-limiting element, wherein the ignition element is connected to an electric-arc combustion chamber of the first individual spark gap and is electrically connected on the one side to the first electrode and on the other side via the voltage-limiting element to the second contact element.