Surge protective device (SPD) and trip mechanism thereof

Abstract

The invention discloses a surge protective device (SPD) and a trip mechanism of the SPD. The trip mechanism comprises a support and a trip rod, wherein the support is used for containing at least one metallic oxide rheostat, and the trip rod is arranged on the support in a pivotal mode and connected with one of electrodes of the metallic oxide rheostat through low-temperature soldering flux. The trip mechanism further comprises a sliding block, the sliding block is arranged between a first position and a second position on the support in a sliding mode and obliquely pressed to a trip position, and under the normal working condition, the sliding block is maintained in the first position due to the fact that the oblique press is overcome by the trip rod. under the trip condition, under the action of the oblique press, the sliding block slides towards the second position to cause the trip rod to pivotally rotate along the direction which is far from the electrodes of the metallic oxide rheostat.

Description

technical field [0001] The present invention relates to a surge protector, and more particularly to a tripping mechanism for the surge protector. Background technique [0002] Surge protectors are widely used in electrical lines in homes, offices, and industrial places to prevent damage to electrical equipment caused by instantaneous overvoltage in the line. When the electrical circuit or communication line suddenly generates peak current or voltage due to external interference, the surge protector can conduct the shunt in a very short time, so as to avoid the damage of the surge to other equipment in the circuit. [0003] In the most commonly used surge protectors, a component called a metal oxide varistor (MOV) is included to divert excess voltage. The metal oxide varistor has a very large resistance under normal operating conditions, thus, it is basically in an open circuit state, and when the voltage in the circuit exceeds a predetermined value, for example, in the even...

AI Technical Summary

Problems solved by technology

[0009] However, this conventional surge protector tripping mechanism has a problem that the tripping bar 1 basically moves in a plane parallel to the side of the MOV 5, and therefore, even when the tripping bar 1 trips, the tripping The electrical distance between snap rod 1 and the electrodes of MOV 5 is very short, which is not conducive to the electrical isolation between the two in the case of tripping

However, when the temperature rises, since the two trip levers 1 work independently, it is difficult for the tripping mechanism of the above-mentioned prior art to satisfy the synchronous tripping requirements of the two MOVs.

If the two MOVs cannot be guaranteed to trip at the same time, for example, one does not trip and the other trips in the above example, that is, a 20kA standard single-chip MOV may cause a MOV explosion in a 35kA surge environment.

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