Surge arresters and method of dimensioning their arc paths

Abstract

The invention relates to an encapsulated surge arrester (2) based on a spark gap, comprising: two at least partially opposite main electrodes (4; 5) and at least one triggering or ignition auxiliary electrode (3) and present in The arc combustion chamber (6) between the main electrodes. According to the invention, the arc combustion chamber essentially consists of an insert which has in its interior at least one gap-like arc channel (7) whose gap length is a multiple of the gap height or gap diameter, And the inner part consists at least partially of a gas-releasing material, so that a release of gas into the arc channel is achieved.

Description

technical field

[0001] The invention relates to an encapsulated surge arrester based on a spark gap. The invention also relates to a method for dimensioning the arc path of a surge arrester without freewheeling. Background technique

[0002] It is known that overvoltage protection devices are used in electrical and information technology systems and networks for installations including protection of consumers or terminal units.

[0003] Especially in the event of momentary overvoltages, such as lightning events, the overvoltage protection device limits the voltage to non-critical values.

[0004] In the event of an overvoltage event, the voltage is limited by conducting a pulsed current in a transverse path and thus generally parallel to the consumer connections. Spark gaps, varistors, suppressor diodes, gas arresters, capacitors and varistors as well as combinations thereof are known as overvoltage protection devices and protective elements used here.

[0005] Overvoltage...

Examples

Embodiment Construction

[0051] exist figure 1 with 2 The schematic diagram (longitudinal sectional view) shown in is based on the idea of ​​harmonizing the minimum specific energy for ignition of the main spark gap leading to the spark gap with the structure and function of the spark gap so that the voltage requirement for arc generation is higher than Working voltage or grid voltage, so there is no freewheeling.

[0052] The voltage requirement of the arc simply results from the sum of the electrode drop voltage multiplied by the product of the electric field strength of the arc and its length.

[0053] The electrode drop voltage is related to the current intensity and the electrode material used within a certain range. Its magnitude fluctuates between 11 and 20 V in the case of simple spark gaps and common materials and is therefore almost irrelevant for use in, for example, 230 / 400 V AC networks.

[0054] The electric field strength of a free burning spark gap is between about 0.8 and 3 V / mm. ...

technical field

[0001] The invention relates to an encapsulated surge arrester based on a spark gap. The invention also relates to a method for dimensioning the arc path of a surge arrester without freewheeling. Background technique

[0002] It is known that overvoltage protection devices are used in electrical and information technology systems and networks for installations including protection of consumers or terminal units.

[0003] Especially in the event of momentary overvoltages, such as lightning events, the overvoltage protection device limits the voltage to non-critical values.

[0004] In the event of an overvoltage event, the voltage is limited by conducting a pulsed current in a transverse path and thus generally parallel to the consumer connections. Spark gaps, varistors, suppressor diodes, gas arresters, capacitors and varistors as well as combinations thereof are known as overvoltage protection devices and protective elements used here.

[0005] Overvoltage...

Examples

Embodiment Construction

[0051] exist figure 1 with 2 The schematic diagram (longitudinal sectional view) shown in is based on the idea of ​​harmonizing the minimum specific energy for ignition of the main spark gap leading to the spark gap with the structure and function of the spark gap so that the voltage requirement for arc generation is higher than Working voltage or grid voltage, so there is no freewheeling.

[0052] The voltage requirement of the arc simply results from the sum of the electrode drop voltage multiplied by the product of the electric field strength of the arc and its length.

[0053] The electrode drop voltage is related to the current intensity and the electrode material used within a certain range. Its magnitude fluctuates between 11 and 20 V in the case of simple spark gaps and common materials and is therefore almost irrelevant for use in, for example, 230 / 400 V AC networks.

[0054] The electric field strength of a free burning spark gap is between about 0.8 and 3 V / mm. ...

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