In an embodiment a thermal varistor protection device includes a casing, a varistor embedded in the casing, wherein the varistor includes a first metallization electrode, which is only partly covered by an insulating material of the casing to allow an electrically conductive connection, a first terminal wire electrically conductively connected to the first metallization electrode of the varistor and a contact element electrically conductively connected to the first metallization electrode of the varistor in a region where the varistor is not covered by the insulating material, wherein the contact element is pre-stressed to ensure a fast separation of the contact element and the first metallization electrode when the electrically conductive connection between the contact element and the first metallization electrode becomes loose.

The invention relates to a disconnecting device for a surge arrester which is accommodated by a support body, and wherein plug contacts which are connected to at least one arrester element of the surge arrester extend from the support body. The invention further comprises a switching tongue which is connected at a first end to the arrester element via a thermal separating point and with a second end to one of the plug contacts. Furthermore, a spring-preloaded insulating disconnecting bracket which is pivotably mounted on the support body is provided, the spring preload acting on the thermal separating point via the switching tongue. According to the invention, the switching tongue is configured as a straight-surface, elongated, metallic, resiliently elastic disconnecting strip having a rectangular cross-section.

An electric high-voltage device includes a fluid-tight housing, a high-voltage component arranged in the housing, and an insulating liquid in the housing in order to electrically insulate the high-voltage component. The high-voltage component is a passive current collector which is configured to at least temporarily conduct a current of at least 1 kA. There is also described a power converter assembly with the high-voltage device.

A method includes supplying a welding current to a welding zone, monitoring, during a welding current ramp down period of a given short arc welding process cycle, a voltage across a current braking switch that is in an open state and that causes a decrease in welding current being supplied to a welding zone; and when the voltage across the current braking switch that is in the open state reaches a first predetermined voltage threshold, closing the current braking switch before a completion of the welding current ramp down period of the given short arc welding process cycle.

An arrester assembly including a first terminal electrically connected to an energized conductor and a second terminal electrically connected to a ground conductor. The arrester assembly further includes a plurality of arrester modules electrically connected in series between the first terminal and the second terminal and a disconnect device electrically connected in series with the plurality of arrester modules between the first terminal and the second terminal. Components of the arrester assembly are coordinated to disconnect or isolate failed surge arresters without creating a short circuit condition.

A surge protection device has at least one disconnecting device (34), at least one actuating device (36), an indicating device (40), and a shaft (38) mounted for rotation between at least a first position and a second position, the at least one actuating device (36) being variable between a first position and a second position. The shaft (38), the indicating device (40) and the actuating device (36) are formed in such a way and the actuating device (36), when in the first position, is fastened to the at least one disconnecting device (34) so as to be preloaded such that when the disconnecting device (34) is triggered, the actuating device (36) is released and triggers the indicating device (40) by means of the shaft (38). Further, a modular surge protection system is described.

A composite circuit protection device includes: a first positive temperature coefficient (PTC) component; a first voltage-dependent resistor (VDR); a second VDR; and a plurality of conductive leads that correspondingly connect to the first PTC component, the first VDR and the second VDR. The second VDR and the first PTC component are electrically connected in series, the first VDR is electrically connected to the series connection of the first PTC component and the second VDR in parallel, and the first VDR has a varistor voltage greater than that of the second VDR as determined at 1 mA.

A circuit protection device including a PTC device having a PTC element, first and second electrodes disposed on opposing first and second surfaces of the PTC element, respectively, first and second chip fuses disposed on the first and second electrodes, respectively, the second chip fuse electrically connected in series with the PTC device, and the first chip fuse electrically in connected parallel with the PTC device and the second chip fuse, the first chip fuse having a lower electrical resistance than the PTC element when the PTC element is in a non-tripped state, wherein a fusible element of the first chip fuse has a first melting temperature and is configured to carry a current higher than the PTC element can carry without tripping, and wherein a fusible element of the second chip fuse has a second melting temperature that is greater than the first melting temperature.

A thermally protected metal oxide varistor includes a body, a first electrode, a thermal fuse, and a glue. The body is made up of a crystalline microstructure including zinc oxide mixed with one or more other metal oxides. The first electrode is located on one side of the body and is connected to a first lead wire. The thermal fuse is connected between the first electrode and the first lead wire. The glue is to be deposited over the thermal fuse as well as over a top portion of the first lead wire.

Disclosed in the present invention is a novel overvoltage protective device for lightning protection, comprising a first varistor, a second varistor, a PTC Thermistor, and lead-out terminals. The first varistor and the PTC Thermistor are connected in parallel, and then further connected in series with the second varistor to form a single port combined circuit. The surge-withstand capability of the first varistor is higher than the surge-withstand capability of the second varistor. At least one of the two lead-out terminals of the single port combined circuit is a thermally-conductive end with low thermal resistance. The second varistor is thermally coupled to the PTC Thermistor. The thermally-conductive end with low thermal resistance is thermally coupled to one or both of the second varistor and the PTC Thermistor.