Cascading type combined surge protector

Abstract

The invention discloses a series-connection combined type surge protector. A pair of arc gaps are formed in an insulating housing; the clearance of the two arc gaps is controlled by the thickness of an insulating gasket, which can be adjusted to determine the protecting voltage of the surge protector; a group of appropriate varistors are further connected in series; the normal current and the ground are isolated by the clearance in a normal state, and the arc extinction is carried out by the varistors in an actuating state; a low-temperature alloy tripping display mechanism is further connected with the varistor combination in series; and when the varistors deteriorate, fail and emit heat to reach a certain temperature, the low-temperature alloy melts, the tripping mechanism actuates, and an alarm is displayed on the housing surface of the surge protector. The surge protector has the advantages that the protection function is strong, the actuating time is short, the after flow is avoided, the arc extinction can be carried out under the condition that the power current is not over zero, the current leakage is avoided, the voltage protection level is low, the service life is long, and the surge protector can protect electrical wires and products against damage caused by direct lightning (10 / 350 mus) and indirect lightning (8 / 20 mus) waveform surges at the same time.

Description

1. Technical field [0001] The invention relates to a surge protector, in particular to a series compound surge protector. 2. Background technology [0002] At present, the known surge protectors mainly have two structural forms: voltage switching type and voltage limiting type. The voltage switch type is also the spark gap type, which is a class I surge protector, which protects against the waveform of direct lightning (10 / 350μs), has high impedance when there is no surge, and can immediately conduct through the discharge gap when there is a surge (short circuit ) discharge surge. It has strong discharge capacity, large flow capacity, and basically no leakage current, but high residual voltage (2-4kv), slow response time, and freewheeling. The voltage-limiting type is also a clamping type, which is a class II surge protector. It protects against the waveform of indirect lightning (8 / 20μs). It has high impedance when there is no surge, but as the surge current and voltage r...

AI Technical Summary

Problems solved by technology

The voltage limiting type is also a clamping type, which is a class II surge protector, which protects against the waveform of indirect lightning (8 / 20μs), and has high impedance when there is no surge, but with the rise of surge current and voltage, its impedance Once it reaches the corresponding pulse voltage, its impedance will suddenly become a low value, and the discharge surge will immediately limit the voltage to a certain value. It has large flow capacity, low residual voltage, no freewheeling, and fast response. With multiple protections, the leakage current will gradually increase after long-term use, and the aging (deterioration) speed is relatively fast, so frequent maintenance is required

[0003] Since different structures of surge protectors are suitable for protecting different lightning waveforms, there are certain limitations and each has different advantages and disadvantages.

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