CN111769012A

CN111769012A - Surge protector's backup protection ware and block terminal

Info

Publication number: CN111769012A
Application number: CN202010590335.9A
Authority: CN
Inventors: 李阳斌; 温金泉; 王超; 潘叶镜
Original assignee: Repsun Lightning Protection Co ltd
Current assignee: Repsun Lightning Protection Co ltd
Priority date: 2020-06-24
Filing date: 2020-06-24
Publication date: 2020-10-13

Abstract

The invention provides a backup protector and a distribution box of a surge protector, wherein the backup protector comprises a resistor module R, an overcurrent switch F and a switch tube G, the resistor module R is connected with the overcurrent switch F in series, and the resistor module R is connected with the overcurrent switch F in series and then connected with the switch tube G in parallel; the time of the resistance module R for bearing lightning current impact is longer than the response time of the gas discharge tube G; the backup protector and the distribution box of the surge protector are good in safety performance, small in size and convenient to install.

Description

Surge protector's backup protection ware and block terminal

Technical Field

The invention relates to the field of circuit protection devices, in particular to a backup protector and a distribution box of a surge protector.

Background

In GB21431 "technical specification for detection of lightning protection devices in buildings", it is specified that a corresponding backup protector must be installed at the front end of the surge protector, but there is no corresponding special product in industry, and an air switch is generally used as a backup protector in engineering. The air switch as a backup protector has the following disadvantages: the impulse current resistance is small, and the false operation of disconnection can be caused under the lightning impulse; the surge protector can not be disconnected with a power supply line when the continuous current is less than the idle rated current, and the surge protector has burning risk. In order to meet the requirements of safety and installation at the same time, a professional backup protector is urgently needed.

Disclosure of Invention

In view of the above, there is a need for a backup protector for a surge protector and a distribution box that can satisfy both safety and installation requirements.

The embodiment of the invention provides a backup protector of a surge protector, which is suitable for being used as a backup breaker of the surge protector and comprises a resistor module R, an over-current switch F and a gas discharge tube G, wherein the resistor module R is connected with the over-current switch F in series, and the resistor module R is connected with the over-current switch F in series and then connected with the discharge tube G in parallel.

Preferably, the circuit formed by the resistor module R and the overcurrent switch F in series can bear the lightning impulse impact before the gas discharge tube G is conducted, and the impact endurance time is longer than the response time of the gas discharge tube G; the resistance module R is formed by one or more thermistors which are connected with each other.

Preferably, the backup protector further comprises a tripping device K of the gas discharge tube G, the tripping device K is connected in series with the gas discharge tube G, and an input end of the tripping device K is equipotential with an input end of the resistance module R and is used for connecting an external power supply circuit.

Preferably, the trip device comprises a trip device body, a connecting electrode, a trip electrode, a first spring and a pushing sheet, wherein one end of the first spring is connected with the trip device body, the other end of the first spring is connected with the pushing sheet, the pushing sheet is movably connected to the trip device body, and the pushing sheet can move relative to the trip device body under the driving of the first spring; the connecting electrode is connected to the tripping device body, and the tripping electrode is fixed on the tripping device body; in a first state, the connecting electrode is fixedly connected with the tripping electrode, the first spring is in a deformed state, and the pushing sheet abuts against the connecting electrode; in a second state, the connecting electrode is disconnected with the tripping electrode, the first spring is reset, the pushing sheet moves towards the connecting electrode, and the connecting electrode can move relative to the tripping device body.

Preferably, the trip device K further includes a first electrode and a second electrode, the first electrode is electrically connected to the switch electrode, the second electrode is electrically connected to the connection electrode, and the first electrode and the second electrode protrude from the trip device body.

Preferably, the protector further comprises a thermal melting piece, an input end of the thermal melting piece is electrically connected with the tripping electrode, and an output end of the thermal melting piece is electrically connected with the gas discharge tube G.

Preferably, the overcurrent switch F includes a base, a first conductive member, a second conductive member, an insulation cut-off piece, a first contact member and a second contact member, the first conductive member and the second conductive member are fixed on the base, the base is insulated from the first conductive member and the second conductive member, and the insulation cut-off piece is also connected to the base; the first contact element is electrically connected with the first conductive element, and the second contact element is electrically connected with the second conductive element; in a first state, the first contact element is electrically connected with the second contact element, the insulation cutting piece is positioned on one side of the first contact element and one side of the second contact element, and the insulation cutting piece is abutted against the connection position of the first contact element and the second contact element; in the second state, the insulation cutting piece is inserted between the first contact piece and the second contact piece, and the first contact piece and the second contact piece are electrically isolated.

Preferably, the insulating cut piece comprises a cut piece body and a second spring, and one end of the cut piece body, which is close to the first contact piece and the second contact piece, is in a blade shape; one end of the second spring is fixedly connected with the cut-off piece body, and the other end of the second spring is fixedly connected with the base; when the cutting piece body is abutted to the joint of the first contact piece and the second contact piece, the second spring is in a compressed state.

Preferably, the response time of the gas discharge tube G is 50-200 nS; the starting voltage of the gas discharge tube is 100-1000V, and the cut-off voltage of the gas discharge tube is not less than the starting voltage of the surge protector; the through-flow capacity of the gas discharge tube is not less than the maximum value of the through-flow of the surge protector; the resistance value of the resistance module is 0.5-200 omega.

The invention also provides a distribution box, which comprises a distribution box body and any one of the backup protectors of the surge protector, wherein the backup protector of the surge protector is arranged in the distribution box body.

The backup protector can be used as a front-end protector of a surge protector, and has the following advantages: 1) the surge protector is impact-resistant and can adapt to impact parameters of the surge protector; 2) the pressure drop resulting from the impulse cascade; 3) when the current exceeds the set continuous current, the connection with the power supply line is disconnected, so that the disconnection after overcurrent is realized; 4) the action of the surge protector cannot be lagged; 5) the protector has a self tripping device, switch indication and signal output of the protector switch state, and intelligent monitoring is easy; 6) the volume is small, and the surge protector can be combined and integrally installed in a general lightning protection module, so that the installation space and the cost are saved.

Drawings

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings. Like reference numerals refer to like parts throughout the drawings, and the drawings are not intended to be drawn to scale in actual dimensions, emphasis instead being placed upon illustrating the principles of the invention.

FIG. 1 is a circuit diagram of the present invention;

FIG. 2 is a waveform diagram illustrating response time under lightning current surge according to an exemplary embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an overcurrent switch according to a preferred embodiment of the invention;

FIGS. 4-1 and 4-2 are two different state diagrams of the gas discharge tube trip device of the present invention;

fig. 5 shows the test results of the T1 surge protector 25KA without the protector;

fig. 6 is a result of a test of T1 surge protector 25KA with the protector of the present invention in place;

fig. 7 shows the test results of T2 surge protector 20KA without the protector;

fig. 8 is a graph showing the results of a test of a T2 surge protector 20KA with the protector of the present invention in place;

FIG. 9 shows the test result of the T2 surge protector 40KA when the air switch is used as the protector;

FIG. 10 shows the results of a test of the surge protector 40KA of T2 without the protector

Fig. 11 shows the results of a test of a T2 surge protector 40KA with the protector of the present invention in place;

fig. 12 shows the test result of T2 surge protector 20KA when the air switch is used as a protector.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element and be integral therewith, or intervening elements may also be present. The terms "mounted," "one end," "the other end," and the like are used herein for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As shown in fig. 1 to 12, a backup protector of a surge protector includes a resistance module R, an overcurrent switch F, a gas discharge tube G trip device K, and a connection electrode. The resistance module R is connected with the overcurrent switch F in series; the resistance module R is connected with the overcurrent switch F in series and then connected with the gas discharge tube G in parallel.

In a preferred embodiment, the resistor module R is an impact-resistant thermistor, and the resistor module R receives the lightning impulse impact before the switch tube G is started, and the lightning impulse impact is longer than the starting time of the gas discharge tube G. Specifically, when the resistor module R is in a lightning surge, the voltage difference generated between the two ends of the resistor module R should be greater than the voltage required for starting the switching tube G. The resistance module R is formed by one or more thermistors which are connected with each other, and a plurality of resistors are connected in series or in parallel, or are used in combination of series connection and parallel connection to form the resistance module R.

In a preferred embodiment, the backup protector further includes a tripping device K, the tripping device K is connected in series with the switching tube G, and an input end of the tripping device is equipotential with an input end of the resistance module R (the input end is one end close to a phase line L of the power supply line), that is, the tripping device and the resistance module R are both directly connected to the L line.

Referring to fig. 4-1 to 4-2, in a preferred embodiment, the trip device K includes a trip device body 51, a pushing piece 52, a trip electrode 53, a connecting electrode 54 and a first spring 55, one end of the first spring 55 is connected to the trip device body 51, the other end is connected to the pushing piece 52, the pushing piece 52 is movably connected to the trip device body 51 under the driving of the first spring 55, and the pushing piece 52 is movable relative to the trip device body 51 under the driving of the first spring 55. The connecting electrode 54 is movably connected to the trip device body 51, and the trip electrode 53 is fixed on the trip device body 51. In the first state, the connection electrode 54 is fixedly connected with the trip electrode 53, the first spring 55 is in a deformed state, and the pushing piece 52 abuts against the connection electrode 54; in the second state, the connection electrode 54 is disconnected from the trip electrode 53, the first spring 55 is reset, the push piece 52 moves toward the connection electrode 54, and the connection electrode 54 moves relative to the trip device body 51.

In a preferred embodiment, the trip device K further includes a first electrode 61 and a second electrode 62, the second electrode 62 is electrically connected to the trip electrode 53, the second electrode 62 is electrically connected to the connection electrode 54, and the first electrode 61 and the second electrode 62 protrude from the trip device body 51. The protector further comprises a hot melting piece D, wherein the input end of the hot melting piece D is electrically connected with the tripping electrode, and the output end of the hot melting piece D is electrically connected with the gas discharge tube G. The thermal melting element D may be a thermal melting point connecting the two electrodes, and the thermal melting point is solder. Of course, the thermal fuse may also include two electrodes and a solder for soldering the two electrodes.

A phase line L of a power circuit is in plug connection with a first electrode 61, a second electrode 62 is in plug connection with the positive end of a surge protector through a lead or a customized connection electrode, a resistance module R is connected in series with an overcurrent switch F and then connected in parallel with the first electrode 61 and the second electrode 62, and a mould is shared, so that a standard plug-in module with the width of 1P is formed. According to the principle diagram of the invention, the tripping principle process is as follows:

1) after the surge protector is damaged by short circuit in the moment of impact, the gas discharge tube G may have follow current under the action of power frequency continuous current due to the characteristic of the switching tube after lightning current disappears.

2) The freewheeling causes the gas discharge tube G to heat up and melt the welded connection between the connecting electrode 54 and the trip electrode 53 of the switching tube, and the pushing piece 52 pushes the connecting electrode 54 away from the trip electrode 53 under the action of the first spring 55, as shown in fig. 4-2.

Referring to fig. 3, in a preferred embodiment, the overcurrent switch F comprises a base 2, a first conductor 11, a second conductor 12, an insulation-breaking assembly, a first contact 41 and a second contact 42, the first conductor 11 and the second conductor 12 being fixed with respect to the base 2, possibly in the illustrated juxtaposed configuration, while the first conductor 11 and the second conductor 12 are in the axial configuration with respect to the base 2; the first contact 41 is electrically connected with the first conductor 11 through the overcurrent thermal sensing conductor 33, and the second contact 42 is electrically connected with the second conductor 12; in the first state, the first contact 41 is electrically connected with the second contact 42, the insulation breaking component is located at one side of the first contact 41 and the second contact 42, and the insulation breaking component is abutted to the connection position of the first contact 41 and the second contact 42; in the second state, the insulation-breaking assembly is inserted between the first contact 41 and the second contact 42.

In a preferred embodiment, the insulation displacement assembly 3 includes a displacement body 32 and a second spring 31, and one end of the displacement body 32 near the first contact 41 and the second contact 42 is knife-edged, i.e., the end is knife-edged. One end of the second spring 31 is fixedly connected with the cut piece body 32, and the other end is fixedly connected with the base; when the cut piece body 32 abuts on the joint of the first contact 41 and the second contact 42, the second spring 31 is in a compressed state. Under normal conditions, the first contact member 41 and the second contact member 42 are in contact with each other, when the overcurrent switch F has an overcurrent continuously larger than a set value, the overcurrent heat induction conductor 33 tilts due to the action of heat generated by the overcurrent, the first contact member 41 and the second contact member 42 are bounced, the cut-off piece body 32 is inserted between the first contact member 41 and the second contact member 42 under the pushing of the second spring 31, the contact connection is cut off, and the overcurrent switch F is in a disconnected state, so that the overcurrent protection purpose is achieved. Due to the irreversibility of the failure of the surge protector, the over-current switch F is also set to be irreversible, and the bimetallic strip contact cannot be contacted again. When a continuous current flows through the overcurrent switch F, the overcurrent heat-sensing conductor 33 is elastically deformed due to its metal property, the second spring 31 pushes the cut-off piece 3 to be inserted into the connection between the first contact 41 and the second contact 42, and the overcurrent switch F is in an off state.

For a 380V power supply system, when a surge protector fails, due to the influence of internal resistance and resistance of a grounding device, the current flowing through the surge protector is generally several amperes to dozens of amperes and is smaller than the rated overcurrent breaking current of a common air switch, and at the moment, the air switch is selected as a protector, so that the air switch cannot play a role in cutting off, and the surge protector burns seriously. When the current is set to be overcurrent, the smaller the current is, the better the current is, but the impact resistance current is also relatively smaller.

The protector has the characteristic of bearing the instant impact of the pulse current of the set lightning current and also has the function of overcurrent cutoff when the continuous power frequency small current flows.

In a preferred embodiment, the response time of the gas discharge tube G is 50-200nS, specifically, the response time of the gas discharge tube G is 60nS, 70nS, 80nS, 90nS, 100nS, 110nS, 120nS, 130nS, 140nS, or 180 nS. The starting voltage of the gas discharge tube G is 100-1000V, specifically 100V,200V,300V, 400V, 500V, 600V or 800V. The choice of values can be experimentally obtained according to the methods described herein.

As shown in fig. 1, the device in the dashed frame is a schematic circuit diagram of the protector of the present invention, and is composed of a resistor module R (such as a thermistor), an overcurrent switch F (which is on in a normal state), a gas discharge tube G (which is in a high-resistance off state in a normal state), a trip device K of the gas discharge tube G, and a thermal fuse D (which can use low-temperature solder). The line phase line L of the power frequency circuit is connected with the input end of the protector at the point A, and the output end of the protector is connected with the input end of the surge protector at the point B. The output end of the surge protector is connected with the neutral line N or the ground line at the point C. The working principle is as follows:

1) when lightning current pulse flows through the protector, the device provides a current path for lightning current, and the action process is as follows:

1.1) applying lightning waves across the AC (C is ground or line neutral), noting that the voltage drop across the AC is UAC, the voltage drop across the AB is UAB, and the voltage drop across the BC is UBC.

1.2) when the lightning current is at the beginning of the pulse waveform (called as lightning wave below), the circuit A-R-F-B is in a low-resistance path, the circuit A-G-B is in a cut-off state, the SPD is in a cut-off state, the cut-off resistance of the SPD is far larger than the resistance value of the resistor module due to the cut-off of the SPD, the voltage applied to two ends of AC is almost divided to two ends of BC at the initial rising stage of the lightning wave pulse, and then UAB is approximately equal to 0 v. There is no change in hysteresis UBC. The action response of the SPD is not affected.

1.3) as the lightning wave pulse rises, the voltage drops to UBC and rises, the SPD is changed from the cut-off state to the conducting state, the internal resistance of the SPD approaches to 0 omega, and the voltage applied to the two ends of the AC is divided to the two ends of the AB at this time due to the resistance function of the resistance module.

1.4) when UAB reaches the conduction condition of the gas discharge tube G, the gas discharge tube G is conducted, the circuit A-G-B is through, the resistance value of the resistance module is far larger than the conduction resistance value of the gas discharge tube G approaching 0 omega, and most of lightning current flows through the gas discharge tube G.

1.5) after the lightning current disappears, the SPD returns to the high-resistance cut-off state, and the gas discharge tube G returns to the high-resistance cut-off state.

The technical key points of the protector used as a lightning current path are as follows: the resistor module and the overcurrent switch F device are required to withstand the set lightning current impact before the gas discharge tube G is not conducted; the matching between the resistor module and the gas discharge tube G makes it possible to conduct the gas discharge tube G for a set time in response to the rise of the lightning wave.

2) When the surge protector fails, the surge protector should complete the tripping action under the normal condition to separate the surge protector from the power supply line, and if the surge protector fails to act as expected, the protector plays the role of an overcurrent switch after the lightning current disappears to assist the surge protector in separating the surge protector from the power supply line. The protector plays a role in limiting current and cutting off, and can cut off the connection with a power supply line when the self tripping of the surge protector fails.

The failure of the surge protector is divided into two states of an instant irreversible short circuit state and a low resistance state of factors such as aging and the like, and the protector disclosed by the invention is suitable for the cutting protection of the two states:

2.1) surge protector SPD strikes the condition when short circuit failure in the twinkling of an eye, and its process of action is:

2.1.1) internal resistance of internal devices of the surge protector SPD approaches 0 omega.

2.1.2) after the lightning current disappears, the power frequency current is directly applied to the gas discharge tube G in a conducting state, the continuous power frequency current is far smaller than the lightning current, and the gas discharge tube G has the power frequency current resistance characteristic within a certain time under the action of the power frequency current.

2.1.3) the circuit A-R-F-B is still in a low-resistance path state at the moment, the power frequency current flows into the earth or a neutral line from the circuit A-R-F-B-C for backflow, the resistance value of the thermistor NTC is reduced under the action of the current, so that the current flowing through the overcurrent switch F is far larger than the set value of the overcurrent switch F, and the effects are that the overcurrent switch F is disconnected and the circuit A-R-F-B-C is cut off. Thereby separating the surge protector SPD from the power supply line.

2.2) the situation when the surge protector SPD ages inefficacy daily, its course of action is:

2.2.1) the surge protector SPD ages to reduce the internal resistance of the internal device to several Ω to several hundred Ω, and the current flowing through the SPD is several MA to several tens of amperes.

2.2.2) if the gas discharge tube G is in a conducting state at this time, the gas discharge tube G enters a low-current heating tripping state, and finally the gas discharge tube G is in a cut-off state.

2.2.3) the gas discharge tube G is in a cut-off state, the circuit A-R-F-B-C is in a low-resistance state, and the power frequency current flows into the earth or a neutral line from the circuit A-R-F-B-C for backflow.

2.2.4) on one hand, because of the resistance value of the resistor R, the power frequency current is limited, so that the surge protector continues the tripping process under a small current, and the effect of delaying the tripping time of the surge protector is achieved, on the other hand, the resistance value of the thermistor is reduced under the influence of the power frequency current, so that the current flowing through the overcurrent switch F is increased, and when the current is larger than the set value of the overcurrent switch F, the overcurrent switch F is disconnected. The circuit A-R-F-B-C is turned off. Thereby separating the surge protector SPD from the power supply line.

In a preferred embodiment, the resistance module R is composed of one or more thermistors NTC connected in series, the gas discharge tube G can be a gas discharge tube device, and the over-current switch can be an electric over-current switch or a dedicated over-current switch designed by the scheme, preferably the dedicated over-current switch in the present invention.

The cut-off voltage of the gas discharge tube G is not less than the maximum value of the high-resistance cut-off of the surge protector. For a 380VAC power system, 600VDC is typically selected, and other values may be used, as measured by experimental data from surge protectors that may be matched. When the surge protector is installed as shown in fig. 1, the test condition is that the current value flowing through the circuits a-G-B is 0 under the power frequency current.

In a preferred embodiment, the gas discharge tube G has a through-flow capacity not less than the maximum surge protector flow capacity. According to the parameters of the surge protector, 5-200KA (8/20US, in the case of T2 surge protector) or 5-100KA (10/350US, in the case of T1 surge protector) can be selected.

In a preferred embodiment, the resistance value of the resistor module R is matched with the turn-on voltage and the response time of the gas discharge tube G, i.e. the surge voltage and the surge time of the resistor module R are greater than those of the gas discharge tube G. Before the gas discharge tube G is switched on, the resistor module and the overcurrent switch F are required to bear the set lightning current impact, and meanwhile, the resistance value of the resistor module is made to be as small as possible. The invention tests the matching of the resistance values of a gas discharge tube and a resistance module, for example, the matching of a temperature sensing device NTC formed by connecting two NTCs with static resistance value of 20 omega and steady-state current of 20A in parallel, a rated current 20A overcurrent switch and a gas discharge tube of 600V100KA, and more matching data of the resistance module, the overcurrent switch F and the gas discharge tube G can be calculated according to the principle circuit and the matching principle of the invention shown in figure 1 and verified by tests. According to the characteristic of the gas discharge tube G, the resistance of the resistor module may be 0.5-200 Ω, and specifically, the resistance of the resistor module is 0.5 Ω, 1 Ω, 5 Ω, 10 Ω,20 Ω,30 Ω, 40 Ω, 60 Ω, 80 Ω, 100 Ω, 120 Ω, 150 Ω, 160 Ω, 180 Ω or 200 Ω. The above values are matched experimentally according to different through-flow capacities.

Referring to fig. 2, the principle of extrapolation: take 8/20US40KA impact resistance as an example.

4.1) the response time of the gas discharge tube G is set to 200NS, and the starting voltage is 600V; such as the 8/20US lightning current waveform of fig. 2.

4.2) the resistance module and the over-current switch F completely bear all lightning current before the time point t1 when the voltage of the lightning wave is less than 600V, and the instantaneous current X1 of the resistance module and the over-current switch F is obtained corresponding to the time point.

4.3) point in time T1+200NS yields the instantaneous current X2 at which the resistance module and the overcurrent switch F are obtained. At this time, the gas discharge tube G is completely subjected to the lightning wave current

4.4) selecting the resistance module and the tolerance value of the overcurrent switch F according to the values X1 and X2. The larger the lightning current surge is, the higher the tolerance value of the resistor module and the overcurrent switch F is selected.

The protector can be used as a front-end protector of a surge protector, and has the following advantages: 1) the surge protector is impact-resistant and can adapt to impact parameters of the surge protector; 2) the pressure drop resulting from the impulse cascade; 3) when the current exceeds the set continuous current, the connection with the power supply line is disconnected, so that the disconnection after overcurrent is realized; 4) the action of the surge protector cannot be lagged; 5) the protector has a self tripping device, a switch indication and a signal output of the protector switch state; 6) the volume is small, and the surge protector can be combined and integrally installed in a general lightning protection module, so that the installation space and the cost are saved. .

The backup protector is used as an auxiliary protection device of the surge protector, and has only insufficient protection effect, and needs to ensure that the backup protector does not have negative influence on the lightning protection function of the surge protector. We performed a series of experiments to verify if it would negatively affect the protection of the surge protector.

Examples of the experiments

Test example 1: a T2 voltage limiting surge protector with the characteristics of Uc (385 VAC), In (20 KA) and Imax (40 KA) is adopted to carry out 8/20US lightning wave test;

test example 2: a test of 10/350US lightning wave was performed using a T1 switching surge protector with Uc 385VAC and Iimp 25 KA.

1) Test results of T1 surge protector (10/350US)25KA without protector, refer to fig. 5:

2) test results of T1 surge protector (10/350US)25KA when the protector is set, refer to fig. 6:

3) test results of T2 surge protector (8/20US)20KA without protector, refer to fig. 7:

wave head (mu S)	Wave tail (mu S)	Peak value (kA)	Residual pressure (V)
				8.39	22.45	21.06	1723.77

4) The test result of the T2 surge protector (8/20US)20KA when the protector is arranged refers to the figure 8:

wave head (mu S)	Wave tail (mu S)	Peak value (kA)	Residual pressure (V)
				9.28	23.46	20.23	2199.42

5) Comparing the test results of the T2 surge protector (8/20US)20KA when an air switch is arranged as a protector, refer to fig. 9:

wave head (mu S)	Wave tail (mu S)	Peak value (kA)	Residual pressure (V)
				9.23	23.63	20.23	2159.79

6) Test results of T2 surge protector (8/20US)40KA without protector, refer to fig. 10:

wave head (mu S)	Wave tail (mu S)	Peak value (kA)	Residual pressure (V)
				8.28	22.13	39.63	2475.43

7) The test result of the T2 surge protector (8/20US)40KA when the protector is arranged refers to the figure 11:

wave head (mu S)	Wave tail (mu S)	Peak value (kA)	Residual pressure (V)
				9.02	23.29	38.81	3293.92

8) Comparing the test results of the T2 surge protector (8/20US)20KA when an air switch is arranged as a protector, refer to fig. 12:

wave head (mu S)	Wave tail (mu S)	Peak value (kA)	Residual pressure (V)
				8.7	23.32	37.98	3253

Data analysis

In the waveform diagram, there is no difference in response time of the surge protector when the protector is not provided, the air switch is provided as the protector, and the protector of the present invention is provided.

The influence of the protector on the impact residual voltage is set,

the data in the table show that under the test of the same waveform and the same impact current, the recorded impact residual voltage when the backup protector is added is higher than that when the backup protector is not arranged, the impact residual voltage recorded when the air switch is used as the protector and the protector of the invention is in an error range. Therefore, the protector of the invention can not influence the impact residual voltage of lightning current.

In summary, the protection device of the present invention does not affect the response time and the impact residual voltage of the surge protection device, and therefore, the surge protection device of the present invention can be matched with the surge protection device to further protect the circuit.

The invention also provides a surge protector which comprises any one of the backup protector and the surge protector body, wherein the backup protector is connected with the surge protector in series, and the structural integration is realized in a universal lightning protection module.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above examples only express specific embodiments of the invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The utility model provides a surge protector's backup protection ware which characterized in that, is applicable to as surge protector's backup circuit breaker, including resistance module R, overcurrent switch F and gas discharge tube G, resistance module R with overcurrent switch F establishes ties after with discharge tube G is parallelly connected in parallel.

2. A backup protector for a surge arrester according to claim 1, wherein a circuit of the resistor module R in series with the overcurrent switch F is capable of withstanding a lightning impulse shock before the gas discharge tube G is turned on for a duration longer than a response time of the gas discharge tube G; the resistance module R is formed by connecting one or more thermistors in series and parallel.

3. A backup protector for a surge arrester according to claim 1, characterized in that it further comprises a tripping device K for a gas discharge tube G, said tripping device K being connected in series with said gas discharge tube G, the input of said tripping device K being equipotential with the input of said resistor block R and being adapted to be connected to an external supply circuit.

4. The backup protector for surge arrester of claim 3, wherein said tripping gas discharge tube G means comprises a tripping device body, a connection electrode, a tripping electrode, a first spring and a pushing piece, one end of said first spring is connected to said tripping device body, the other end is connected to said pushing piece, said pushing piece is movably connected to said tripping device body, said pushing piece is movable relative to said tripping device body under the driving of said first spring; the connecting electrode is connected to the tripping device body, and the tripping electrode is fixed on the tripping device body; in a first state, the connecting electrode is fixedly connected with the tripping electrode, the first spring is in a deformed state, and the pushing sheet abuts against the connecting electrode; in a second state, the connecting electrode is disconnected with the tripping electrode, the first spring is reset, the pushing sheet moves towards the connecting electrode, and the connecting electrode can move relative to the tripping device body.

5. The backup protector for surge arrester of claim 4, wherein said trip unit K further comprises a first electrode and a second electrode, said first electrode is electrically connected to said switching electrode, said second electrode is electrically connected to said connecting electrode, and said first electrode and said second electrode protrude from said trip unit body.

6. The backup protector for surge protector according to claim 4, further comprising a thermal fuse, wherein an input end of said thermal fuse is electrically connected to said trip electrode, and an output end of said thermal fuse is electrically connected to said gas discharge tube G.

7. A backup protector for a surge arrester according to claim 1, wherein the overcurrent switch F comprises a base, a first conductive member, a second conductive member, an insulation cut-off member, a first contact member, and a second contact member, the first conductive member and the second conductive member being fixed to the base, the base being insulated from the first conductive member and the second conductive member, the insulation cut-off piece being also connected to the base; the first contact element is electrically connected with the first conductive element, and the second contact element is electrically connected with the second conductive element; in a first state, the first contact element is electrically connected with the second contact element, the insulation cutting piece is positioned on one side of the first contact element and one side of the second contact element, and the insulation cutting piece is abutted against the connection position of the first contact element and the second contact element; in the second state, the insulation cutting piece is inserted between the first contact piece and the second contact piece, and the first contact piece and the second contact piece are electrically isolated.

8. The surge arrester backup protector according to claim 7, wherein the insulation cut-off assembly includes a cut-off body and a second spring, the cut-off body having a blade-like shape near one end of the first contact member and the second contact member; one end of the second spring is fixedly connected with the cut-off piece body, and the other end of the second spring is fixedly connected with the base; when the cutting piece body is abutted to the joint of the first contact piece and the second contact piece, the second spring is in a compressed state.

9. A backup protector for a surge protector according to claim 1, wherein said gas discharge tube G has a response time of 50 to 200 nS; the starting voltage of the gas discharge tube is 100-1000V, and the cut-off voltage of the gas discharge tube is not less than the starting voltage of the surge protector; the through-flow capacity of the gas discharge tube is not less than the maximum value of the through-flow of the surge protector; the resistance value of the resistance module is 0.5-200 omega. The overcurrent switch can be set to be 0.5A-63A

10. An electrical distribution box comprising an electrical distribution box body and a surge protector backup protector according to any of claims 1-9, wherein said surge protector backup protector is mounted within said electrical distribution box body.