KR20220167600A - Method and Device for Thermal Imaging Diagnosis of Overhead Gas Insulated Switchgears - Google Patents

Abstract

According to a method for diagnosing a thermal image of a processing switch using a thermal imaging diagnosis device (1) of a processing switch according to the present invention, in a state where the abnormal temperature of a processing switch (100) is confirmed by the thermal image temperature image (20-1) of a thermal imager (20), a precision resistance meter (30) measures a resistance value at a connection point of upper and lower contact pins (10A, 10B) of a clamp (10) by electrical conduction of a current generator (40) engaged with a terminal (101). By checking the resistance measurement value as an excess resistance value through the reference resistance value of the switchgear resistance-temperature map, the electrical contact defect of the terminal (101) is resolved. The reliability of thermal imaging diagnosis is improved and work convenience is provided. In particular, while the structure of increasing contact points with the terminal-side wires (102B, 103B) by the upper and lower contact pins (10A, 10B) of the clamp (10) provides ease of resistance measurement and measurement accuracy, and through thermal imaging diagnosis, terminal fastening defects which do not require removal are accurately identified. Cost reduction is achieved by preventing indiscriminate removal and replacement of the processing switch (100).

Description

Process switchgear thermal imaging diagnosis method and device {Method and Device for Thermal Imaging Diagnosis of Overhead Gas Insulated Switchgears}

The present invention relates to thermal imaging diagnosis of processing switch, and in particular, thermal imaging diagnosis of processing switch capable of performing a method for diagnosing processing switch thermal imaging in which a reference resistance value for a terminal-side resistance value is used to prevent indiscriminate removal only with temperature abnormalities. It's about the device.

In general, overhead gas insulated switchgears are a mechanism that opens or connects distribution lines. Circuit protection that changes the opening/closing state of high-voltage circuits by detecting current or voltage generated on high-voltage lines of high-voltage circuits installed on electric poles, etc. It is a device.

There are many cases of detection of these overhead switchgear for distribution according to the thermal imaging diagnosis of the switch of Eco switch, Recloser (Automatic Circuit Recloser), and EFI (Epoxy insulated Fault Interrupters). In this case, the Eco switch is a load switch for installing wiring lines of an epoxy insulation method, and the recloser is used to block temporary failures of distribution lines or to separate and block accident sections, and the EFI uses epoxy, not SF6 gas. A circuit breaker with a breaking time of 3 cycles or less applied as an insulating medium.

For example, in the case of thermal imaging diagnosis of the switchgear, defects in fastening clamps such as clamp fastening parts, bushing parts, and opening/closing parts and surface corrosion are the causes.

Specifically, the cause of the clamp fastening part is due to clamp connection failure in the clamp connection state, and the clamp connection failure causes corrosion/arc generation and U-Bolt fastening failure. The cause of the bushing part is due to the opening of the CT (Current Transformer), which brings about a high voltage induction during manual operation of the automated switch. The cause of the opening/closing part is due to an abnormal VI (Vacuum Interrupter) connection due to an increase in contact resistance due to poor connection between the mover and the inner conductor.

Therefore, the overhauled switch can maintain the safety of the distribution line by being replaced with a new product through thermal imaging detection of the switchgear.

Domestic registered patent KR 10-0764066 B

However, the existing thermal imaging diagnosis method has a limitation in that it cannot accurately determine the phenomenon or cause of surface corrosion and clamp fastening failure that requires removal of the switchgear.

This cause is due to the absence of a standard resistance value that determines the connection failure of the processing switch as heat generation by Joule heat, and to the structural disadvantages of fixing the metal-wire of the clamp, which is difficult to install (i.e. bite) the resistance measuring clip for the processing switch. are signing up

As a result, indiscriminate removal of switchgear without accurate thermal image diagnosis causes great losses in that faulty clamping and surface corrosion account for about 90% of the causes of removal of machined switchgear.

Therefore, in view of the above points, the present invention improves the reliability of thermal image diagnosis by applying a reference resistance value capable of diagnosing the cause of clamp fastening failure to the resistance measurement value, while also providing convenience in diagnosis work. The increased contact points of the wire on the terminal side by the contact pin makes it easy to measure resistance and measurement accuracy, while accurately identifying terminal fastening defects that do not require removal. It is an object to provide a method and apparatus.

In order to achieve the above object, the method for diagnosing a thermal image of a processing switch of the present invention verifies a thermal image temperature image in which an abnormal temperature of the processing switch is confirmed as a resistance-temperature map of the processing switch, and through the verification, the terminal side of the processing switch is verified. It is characterized by including a thermal imaging diagnosis verification procedure in which contact failure is confirmed.

As a preferred embodiment, the thermal image temperature image shows the temperature distribution of the machine switch in different colors, and the machine switch resistance-temperature map shows a reference resistance value for the excess resistance value of the terminal.

In a preferred embodiment, the step of the thermal imaging diagnosis verification procedure includes installing a thermal imaging camera around the processing switch, checking the abnormal temperature in the thermal image obtained by the thermal imaging camera, and confirming the abnormal temperature. A thermal image analysis step in which the need for precise diagnosis of the process switch is confirmed by temperature. A clamp is clamped to the terminal, and a precision resistance meter and a current generator are connected to the clamp, the resistance value of the terminal is measured by the precision resistance meter with the current flow of the current generator, and the switchgear resistance - temperature map A reference resistance comparison step in which the verification is performed by confirming the resistance measurement value as an excess resistance value, and a step of removing a contact defect on the terminal side by checking the fastening state of the terminal.

In a preferred embodiment, the thermal imager captures the process switch to generate the thermal image.

As a preferred embodiment, the abnormal temperature is identified by the heat temperature of the processing switch and the ambient temperature of the processing switch shown in the thermal image temperature image, and the abnormal temperature is an ambient temperature greater than the ambient temperature threshold value of 10 to 20 ° C. confirmed by car

In a preferred embodiment, the ideal temperature is identified as the temperature of each phase of the process switch shown in the thermal image temperature image, and the abnormal temperature is identified as a phase-specific temperature difference greater than a temperature threshold value of 5 to 10 °C.

As a preferred embodiment, the work switch is confirmed in a normal state without confirmation of the abnormal temperature.

As a preferred embodiment, the clamp includes a plurality of upper contact pins and lower contact pins, and each of the upper contact pin and the lower contact pin is engaged with an upper wire on the load side terminal side of the terminal or a lower wire on the power side terminal side of the terminal. The current of the current generator flows.

As a preferred embodiment, the excess resistance value is confirmed by a clamp-to-wire resistance difference of a value greater than an excess resistance threshold of 1 mΩ.

In a preferred embodiment, when the excess resistance value is not confirmed by the resistance measurement value, the processing switch is determined to be defective.

In addition, the processing switch thermal imaging diagnosis device of the present invention for achieving the above object is a clamp provided with a plurality of upper contact pins and lower contact pins that form a connection point with a wire by being bitten by the terminal of the processing switch, and heat generation of the processing switch It is characterized in that it includes a thermal imager for generating a thermal image of temperature, a precision resistance meter for measuring the resistance value of the terminal with the current flowing through the clamp, and a current generator that is electrically energized with the clamp.

As a preferred embodiment, the clamp is provided with a plurality of upper contact pins and lower contact pins at predetermined intervals.

The process switchgear thermal imaging diagnosis method and apparatus of the present invention implements the following actions and effects.

First, as the accuracy of the thermal image diagnosis for the processing switch is increased by comparing the resistance value, it is possible to easily determine whether to remove the processing switch in the field. Second, by improving the accuracy of thermal imaging diagnosis for clamp fastening defects and surface corrosion, which account for about 90% of the removal of process switches, indiscriminate site removal of process switches that require replacement costs can be reduced. Third, by establishing a resistance-temperature correlation diagram through a test of clamp connection resistance and heat generation, it is possible to easily diagnose the cause of poor clamping of the processing switch using the standard resistance value in the field. Fourth, the structure of increasing the contact point of the twisted wire resistance of the clamp can solve the difficulty of biting that occurred during the work of the existing clamp bracket-wire fixing structure. Fifth, due to the increased accuracy of the resistance measurement value due to the structure of increasing the contact point of the clamp, thermal imaging diagnosis can be divided into a clamp construction problem requiring fastening work and a switch internal problem requiring replacement work, thereby preventing indiscriminate removal and replacement of processed switchgear. Cost savings are also possible.

1 is a flow chart of a method for diagnosing a thermal image of a switchgear according to the present invention, FIG. 2 is a diagram showing the configuration of a thermal image diagnosis device for a switchgear according to the present invention, and FIG. 3 is a diagram applied to a resistance-temperature map of a switchgear according to the present invention. An example of a graph showing a correlation between clamp-processing switch resistance-temperature using a wire connection point, and FIG. 4 is an example of a thermal image temperature image of an imaging device for diagnosing a thermal image of a processing switch according to the present invention. FIG. 5 is a clamp according to the present invention. is connected to the terminal of the processing switch for resistance measurement.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying exemplary drawings, and since these embodiments can be implemented in various different forms by those skilled in the art as an example, the description herein It is not limited to the embodiment of

Referring to FIG. 1, in the method of diagnosing the thermal image of the processing switch, the thermal image 20-1 (see FIG. 4) in which the abnormal temperature of the processing switch 100 (see FIG. 2) is confirmed is used as the resistance-temperature map of the processing switch. (See FIG. 3), and through the verification, it is implemented as a thermal imaging diagnosis verification procedure (S10 to S50) in which a contact defect on the terminal 101 side of the processing switch 100 is confirmed.

To this end, the step of the thermal imaging diagnosis verification procedure (S10 to S50) is a switchgear excess temperature diagnosis procedure ( S10 to S20), followed by a switchgear excess resistance diagnosis procedure (S30 to S40) that determines the removal of the machined switch with the terminal resistance data obtained from the clamp's switchgear resistance measurement value.

As a result, the process switch removal operation can be classified as one of simple maintenance diagnosis (S50), normal diagnosis (S100) and demolition diagnosis (S200).

Therefore, in the method of diagnosing machined switch thermal imaging, a procedure for determining the reference resistance value for the resistance value of the clamp area is applied, reducing the cost due to the existing thermal imaging diagnosis method in which the machined switch was removed only with the temperature abnormality identified in the thermal image of the switchgear. It is possible to implement a feature that causes a large loss.

Meanwhile, referring to FIG. 2 , the process switch thermal imaging diagnosis apparatus 1 is composed of a clamp 10, a thermal imager 20, a precision resistance meter 30, and a current generator 40.

For example, the clamp 10 is a tool that is clamped to the terminal 101 of the processing switch 100 to measure the resistance value of the terminal 101 in the precision resistance meter 30, and the hinge axis is centered. It consists of two clamp hook structures (i.e., scissors structure) (see FIG. 5) that are clamped to the terminal 101 by motion.

For example, the thermal imager 20 captures an image of the processing switch 100, and the captured image is a thermal image representing the temperature distribution (ie, temperature difference) of the processing switch 100 and its surrounding space in color. A temperature image 20-1 (see FIG. 4) is provided.

For example, the precision resistance meter 30 and the current generator 40 measure the resistance value generated at the terminal 101 of the processing switch 100, and for this, the current generator 40 connects the terminal 101 and A current of about 100 A flows toward the upper and lower contact pins 10A and 10B of the clamp 10, and the precision resistance meter 30 measures the precision resistance with a micro-ohm meter, through which the resistance of the terminal 101 By detecting or measuring the value and analyzing it in conjunction with the temperature of the thermal imager 20, it is possible to check whether or not the fastening state of the clamp bracket to the terminal 101 of the processing switch 100 is defective.

Therefore, the processing switch thermal imaging diagnosis device 1 is a combination of the clamp 10, the thermal imager 20, the precision resistance measuring device 30, and the current generator 40. A resistance-temperature map for terminal 101 can be built.

In particular, FIG. 3 is an example of constructing a processing switch resistance-temperature map using the processing switch thermal imaging device 1, and the processing switch resistance-temperature map is a precision resistance measuring device ( It can be seen that the resistance value of the terminal 101 is constructed as a graph related to the temperature value of the thermal imager 20 by applying the temperature value to the resistance measurement value detected in 30). In this case, the test content changes the contact resistance between the clamp 10 of the processing switch 100 and the terminal wires 102B and 103B while applying a current of about 100A, measuring the resistance and the temperature difference (see table), and drawing a correlation diagram (graph reference).

Therefore, the above process switch resistance-temperature map is based on the ambient temperature difference of the process switch 100 obtained from the switch over temperature diagnosis procedure (S10 to S20) and the terminal of the process switch 100 obtained from the switch over resistance diagnosis procedure (S30 to S40). Temperature matching contributes to determining whether or not contact failure of the terminal 101 is due to poor clamping and surface corrosion, which are the most important causes among the causes of removal of the switchgear.

On the other hand, the processing switch 100 is a circuit protection device that changes the open/closed state of the high-voltage circuit, and the terminal 101 to which the clamp 10 is engaged has a load-side terminal 102A to which an upper wire 102B is connected and a lower wire as shown in FIG. 103B is divided into a power-side terminal 103A to which it is connected. In this case, each of the load-side terminal 102A and the power-side terminal 103A is fixed by fastening a single clamp (or clamp bracket (not shown)).

Hereinafter, the method for diagnosing a thermal image of the processing switch of FIG. 1 will be described in detail with reference to FIGS. 2 to 5.

First, in the process of diagnosing the thermal image of the machine switch 100, in the process of diagnosing the over temperature of the switchgear 100 (S10 to S20), the setting step of the machine switch thermal imaging diagnosis device in S10 and the thermal image analysis step in S20 are performed.

Referring to FIG. 2, in the process switch thermal imaging device setting (S10), a thermal imager 20, a precision resistance meter 30, and a current generator 40 are arranged and installed around the process switch 100. After that, it is performed by connecting power and signal lines. In this case, the clamp 10 may be set at the same time, but it is preferable to install it when the switchgear excess resistance diagnosis procedure (S30 to S40) is performed.

In addition, the step of analyzing the thermal image (S20) is performed in the step of generating a thermal image temperature in step S21, confirming the diagnosis temperature in step S22, and confirming that the first or more diagnosis condition is met in step S23.

4 is a thermal image temperature image 20-1 of the thermal imager 20. The thermal image 20-1 shows the temperature distribution of the process switch 100 and its surrounding space as well as the temperature difference between them. is displayed as a color change for each temperature.

Therefore, in the thermal image temperature image generation (S21), the thermal image temperature image 20-1 may be acquired. The diagnostic temperature check (S22) is the temperature difference between the processing switch 100 and its surrounding space or the terminal ( 101) and the temperature difference between the surrounding space.

For example, the first abnormality diagnosis condition satisfaction check (S23) is performed by the following excess temperature determination formula.

Excess temperature judgment formula

Case 1: A > a ?

Case 2: B > b ?

Here, A is the ambient temperature difference, the temperature difference between the heating temperature of the processing switch 100 and the surrounding environment, a is the ambient temperature threshold set at 10 to 20 ° C, and B is the terminal of the processing switch 100 The (101) side temperature difference b is the temperature threshold for each phase set at 5 to 10 ° C.

As a result, when the ambient temperature difference (A) is less than 10 ~ 20 ℃ (a) or the temperature difference (B) for each phase is less than 5 ~ 10 ℃ (b), the process switch (100) is in a normal state, so S100 The processing switch of the switch is converted to the normal diagnosis stage.

Therefore, conversion of the process switch normal diagnosis (S100) stops the process of the process of the process of diagnosing the process switch thermal imaging.

On the other hand, when the ambient temperature difference (A) is greater than 10 ~ 20 ℃ (a) or the temperature difference (B) for each phase is greater than 5 ~ 10 ℃ (b), the process switch 100 is in an abnormal state in terms of temperature Therefore, it proceeds to the excess resistance diagnosis procedure (S30 to S40).

In this way, the switchgear excess temperature diagnosis procedure (S10 to S20) is the current state of the process switch 100 secured by the thermal image temperature image 20-1 of the thermal imager 20 of the process switch thermal imaging diagnosis device 1. If the measured temperature has a certain temperature difference from the ambient temperature, the need for precise diagnosis before removal of the processing switch 100 can be confirmed.

Subsequently, the procedure of diagnosing the resistance value of the process switch 100 is performed in the clamp fastening step of S30 and the reference resistance comparison step of S40 in the excess resistance diagnosis procedure (S30 to S40).

Referring to FIG. 5, the clamp 10 divides two clamp hooks into an upper clamp hook and a lower clamp hook, has a plurality of upper contact pins 10A on the upper clamp hook, and lower contact pins on the lower clamp hook. A plurality of pins 10B are provided. In this case, each of the upper and lower contact pins 10A and 10B is formed in a rod pin shape having a small cross-sectional size, penetrates the upper and lower clamp hooks at a predetermined interval, and protrudes into the space of the clamp hook.

Therefore, the clamp 10 is engaged with the upper wire 102B of the load-side terminal 102A or the lower wire 103B of the power-side terminal 103A among the terminals 101 of the processing switch 100 by using two clamp hooks. In this case, the plurality of bar-shaped pins constituting the upper and lower contact pins 10A and 10B protruding into the space of the clamp hook form an effective electrical contact with the terminal 101, respectively.

From this, the clamp fastening (S30) makes a state in which electrical contacts between the upper and lower contact pins 10A and 10B of the clamp 10 and the wires 102B and 103B are sufficiently secured, and the precision resistance meter 30 And the current generator 40 is connected to the clamp 10 (ie, the upper and lower contact pins 10A and 10B).

Specifically, the reference resistance comparison (S40) is performed in the terminal resistance data generation step (S41), the diagnostic resistance value check step (S42), and the second or more diagnosis condition satisfaction step (S43).

2 and 4, in the terminal resistance data generation (S41), the precision resistance meter 30 and the current generator 40 are connected to the clamp 10 (ie, the upper and lower contact pins 10A and 10B) and After connection, the precision resistance meter 30 measures the resistance value of the terminal 101 (that is, the wires 102B and 103B) through the current flowing through the current generator 40. In this case, the operation of clamping (S30) is to fasten the clamp 10 to the load-side terminal 102A and measure the resistance value, then fasten the clamp 10 to the power-side terminal 103A and measure the resistance value, or Or vice versa.

For example, the diagnostic resistance value check (S42) is the terminal resistance value measured at the load-side terminal 102A or the power-side terminal 103A, which is the terminal 101 of the processing switch, and the terminal resistance value is the switch clamp-wire of FIG. A connection point resistance-warm result table can be illustrated.

In particular, the satisfaction of the second abnormal diagnosis condition (S43) is performed by the following excess resistance determination formula.

Excess resistance judgment formula: D >d ?

where D is the resistance difference between the clamp and wire, and d is the excess resistance threshold set at 1mΩ.

As a result, when the resistance difference (D) between the clamp and the wire is less than 1 mΩ, the processing switch 100 is in a normal state, and thus the processing switch removal and device defect detailed inspection step of S200 is switched.

Therefore, in the switching of the process switch removal and detailed device defect inspection (S200), the procedure of the process switch thermal image diagnosis method is stopped and the process switch 100 is removed.

On the other hand, when the resistance difference (D) between the clamp and the wires is greater than 1 mΩ, the terminal 101 of the processing switch 100 is in a poor contact state in terms of resistance, so it proceeds to the terminal portion of the processing switch in S50.

Finally, in the step of fastening the terminal part of the processing switch of S50, among the terminals 101 of the processing switch 100 showing the current resistance value or more, the load side terminal 102A and the upper wire 102B and / or the power side terminal 103A and the lower wire Poor contact of the wires 102B and 103B generated from the terminal 101 of the processing switch 100 by re-tightening the terminal clamp (or clamp bracket (not shown)) connecting 103B or replacing it with a new product. condition is resolved

In this way, the excess resistance diagnosis procedure (S30 to S40) is performed by using the current measured resistance value of the processing switch 100 obtained by the precision resistance measuring device 30 of the processing switch thermal imaging diagnosis device 1. By identifying the contact failure, the processing switch 100 to be removed can be clearly identified.

As described above, in the method for diagnosing the thermal imaging of the processing switch using the thermal imaging diagnosis device 1 for the processing switch according to the present embodiment, the thermal imaging temperature image 20-1 of the thermal imager 20 is used to detect the processing switch 100. In the state where the abnormal temperature of is confirmed, the precision resistance meter 30 measures the resistance value at the connection point of the upper and lower contact pins 10A and 10B of the clamp 10 by energizing the terminal 101 and the current generator 40. , and confirms the resistance measurement value as an excess resistance value through the reference resistance value of the switchgear resistance-temperature map to resolve the electrical contact defect of the terminal 101, thereby improving the reliability of thermal imaging diagnosis and providing work convenience In particular, the terminal-side wires (102B, 103B) and the contact point increase structure by the upper / lower contact pins (10A, 10B) of the clamp (10) have the ease of resistance measurement and measurement accuracy, and can be removed through thermal imaging diagnosis. Cost reduction is achieved by preventing indiscriminate removal and replacement of the processing switch 100 by accurately identifying unwanted terminal fastening defects.

1: Process switch thermal imaging diagnosis device
10: clamp 10A, 10B: upper/lower contact pin
20: thermal imager 20-1: thermal image temperature
30: precision resistance meter 40: current generator
100: processing switch
101: terminal 102A: load side terminal
102B: upper wire 103A: power side terminal
103B: lower wire

Claims (18)

The thermal image, in which the abnormal temperature of the processing switch is confirmed, is verified with the processing switch resistance-temperature map,
Thermal imaging diagnosis verification procedure in which contact failure on the terminal side of the processing switch is confirmed by the above verification
Process switch thermal imaging diagnosis method characterized in that it is included.
The method of claim 1 , wherein the thermal image temperature image represents the temperature distribution of the machining switch in different colors.
The method of claim 1 , wherein the machining switch resistance-temperature map indicates a reference resistance value for an excess resistance value of the terminal.
The method according to claim 1, wherein the step of the thermal imaging diagnosis verification procedure
Installing a thermal imaging camera around the processing switch;
A thermal image analysis step of confirming the abnormal temperature in the thermal image temperature image obtained by the thermal imaging camera, and confirming the need for precise diagnosis of the processing switch with the abnormal temperature.
A clamp is engaged with the terminal, and a precision resistance meter and a current generator are connected to the clamp;
A reference resistance comparison step in which the resistance value of the terminal is measured in the precision resistance meter by the current flow of the current generator, and the resistance measurement value is confirmed as an excess resistance value with the processing switch resistance-temperature map, and the verification is performed, and
Eliminating the contact defect on the terminal side by checking the fastening state of the terminal
Process switch thermal imaging diagnosis method, characterized in that carried out as.
The method of claim 4 , wherein the thermal imager captures the machining switch and generates the thermal image temperature image.
The method of claim 4 , wherein the abnormal temperature is confirmed by a heating temperature of the machining switch and a temperature around the machining switch shown in the thermal image temperature image.
The method of claim 6 , wherein the abnormal temperature is confirmed by an ambient temperature difference greater than an ambient temperature threshold.
The method of claim 7 , wherein the ambient temperature threshold is 10 to 20° C.
The method of claim 4 , wherein the abnormal temperature is identified as a temperature of each phase of the machining switch shown in the thermal image temperature image.
10. The method for diagnosing switchgear thermal imaging according to claim 9, wherein the abnormal temperature is identified as a temperature difference (B) between phases having a value greater than a temperature threshold per phase.
The method of claim 10 , wherein the temperature threshold for each phase is 5 to 10° C.
[Claim 5] The method of diagnosing a thermal image of a switchgear according to claim 4, wherein the switchgear is confirmed to be in a normal state without the abnormal temperature being confirmed.
The method according to claim 4, wherein the clamp is provided with a plurality of upper contact pins and lower contact pins,
Each of the upper contact pin and the lower contact pin is bitten by an upper wire on the load-side terminal side of the terminal or a lower wire on the power-side terminal side of the terminal to flow current from the current generator.
The method for diagnosing machine switch thermal imaging according to claim 4 , wherein the excess resistance value is confirmed by a difference in resistance between the clamp and the wires having a larger value than an excess resistance threshold.
15. The method for diagnosing machine switch thermal imaging according to claim 14, wherein the excess resistance threshold is 1 mΩ.
The method for diagnosing machined switch thermal imaging according to claim 4, wherein the machined switch is judged to be defective when the excess resistance value is not confirmed by the measured resistance value.
A clamp provided with a plurality of upper contact pins and lower contact pins that form a connection point with a wire by being bitten by the terminal of the processing switch,
A thermal imager for generating a thermal image of the heating temperature of the process switch,
A precision resistance meter for measuring the resistance value of the terminal with the current flowing through the clamp, and
A current generator electrically energized with the clamp
Process switch thermal imaging diagnostic device characterized in that it is included.
18. The thermal imaging diagnosis device for a switchgear according to claim 17, wherein the clamp includes a plurality of upper contact pins and lower contact pins spaced apart from each other.

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