Novel High-reliability surge protector

Abstract

The invention discloses a novel high-reliability surge protector which comprises a voltage-sensitive resistor (2) located in a module box (1). Two electrodes of the voltage-sensitive resistor (2) are connected with an inner electrode A (3) and an inner electrode B (4) respectively, and a heat separation elastic sheet (5) is connected to a heat separation point of the inner electrode B (4). The thickness of the inner electrode B (4) is 0.9 mm to 2 mm, or a melting-through preventing metal sheet (9) is arranged at the connecting position of the heat separation point of the inner electrode B (4) and the heat separation elastic sheet (5). Due to the fact that the thickness of the inner electrode B (4) is increased or the melting-through preventing metal sheet (9) is added between the inner electrode and the heat separation electrode, a long time is needed to melt through the melting-through metal sheet through short circuit currents formed by chip breakdown, time is gained for the response of a heat separation mechanism, and mechanism reliability is greatly improved.

Description

technical field [0001] The invention relates to a novel high-reliability surge protector, which belongs to the technical field of voltage-limiting protective devices. Background technique [0002] The surge protector uses ZnO lightning protection chip as the main component, combined with thermal detachment mechanism, etc., has the advantages of good nonlinear performance and large flow capacity, and is widely used in electronic circuits and power systems as lightning surge protection components application to ensure the safe operation of the device. However, in practical applications, the long-term lightning impact of the surge protector will reduce the insulation resistance of its lightning protection chip, and the tolerance to power frequency overvoltage will also decrease; In the case of a fault, it is very easy to cause a fire due to the breakdown of the lightning protection chip by the power frequency overvoltage and cause serious consequences. In order to improve the...

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Problems solved by technology

However, the protruding surface or bending surface of the electrode should not be in direct contact with the piezoresistor

The heat conduction should be carried out through the edge of the protruding surface or the bending surface, so the heat conduction area is small, the heat conduction ability is poor, the high heat conduction time before the varistor fails is bound to be long, and the heat detachment response time is relatively lagging; on the other hand, the trip The electrode sheet is relatively thin, mostly in the thickness of 0.4~0.5mm. When the chip breaks down to form a short circuit current, the tripping electrode sheet will be melted in a short time to form a flame.

In the additional test of the IEC61643-11:2011 standard simulating the failure mode of the surge protector, under the condition that the short-circuit current is not less than 100A, the 100A current flows through the SPD, and a large amount of heat is accumulated, causing flames to burn

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