JP2019167026A - Abnormal voltage protection device of electric car track - Google Patents

Abstract

To further improve the ground fault accident protection function in an electric car track.SOLUTION: An abnormal voltage protection device 30 of an electric car track comprises a discharging auxiliary gap circuit 36 connected between a pair of discharging arc horns 13 and 14. In the auxiliary gap circuit 36, a plurality of discharge circuits 40-1 and 40-2 and a discharging backup gap 45 are connected in parallel. A plurality of discharge elements 41 and 42 in the plurality of discharge circuits 40-1 and 40-2 are stored in an insulating case 31, and a plurality of arc generation wires 43 in the plurality of discharge circuits 40-1 and 40-2 are respectively arranged just under the arc horns 13 and 14 on the outside of the insulating case 31.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a train line abnormal voltage protection device for protecting equipment and the like provided on a train line from a ground fault of a power supply circuit (that is, a “feed circuit”) of the train line.

  A train track means equipment such as an overhead line for supplying electric power to a train. A ground fault may occur on this train line. A ground fault accident is an accident in which a feeding current flowing in a train line such as a trolley line or a feeder line flows out to the ground for some reason.

FIG. 6 is a diagram illustrating an image of a ground fault in an AC train line.
A rail 2 is laid on the ground 1. In the vicinity of the rail 2, a structure (for example, a support column) 3 for receiving the feeding current i in the direction of the arrow supplied from the substation is erected. Suspended on the support column 3 are a train line (for example, a trolley line) 4 and a feeder line through which a feeding current i flows, and a protection line 5 through which a short-circuit fault current flows. Lower arm members 8 and 9 are attached to the support column 3 via insulators 6 and 7. A trolley wire 4 is suspended on the lower arm members 8 and 9 via a suspension member 10. An upper arm member 11 is attached to the support column 3 above the trolley wire 4. A protection wire 5 is suspended from the upper arm member 11 via a lever 12.

The trolley wire 4 is insulated from the support column 3 by the insulators 6 and 7. Therefore, normally, the feeding current i does not flow out to the ground 1 from the trolley wire 4. However, due to the rapid fouling of the insulators 6 and 7 caused by the typhoon or contact of birds and flying objects, for example, insulators (insulation breakdown) 7a occurs at the seven insulators, and as shown by arrows, the support columns 3 Through this, the feeding current i may flow out to the ground 1.
In order to prevent this, a ground fault protection system called a discharge gap system (S-shaped horn system) is known.

FIG. 7 is a diagram showing an image of ground fault protection by the S-shaped horn system.
As shown in the part X, a pair of S-shaped arc horns (hereinafter referred to as “S-shaped horns”) 13 and 14 are provided on the insulator 12 that suspends the protective wire 5. One ends of the S-shaped horns 13 and 14 are attached to the upper and lower ends of the insulator 12, and an air discharge gap (hereinafter simply referred to as "discharge gap") 15a is provided between the horns 15 at the other end. When the insulator spiral 7a is generated, the discharge gap terminal voltage rises and discharges, and as shown by the arrow, the ground fault current i which is the feeding current i passes through the ground fault conductor 3a attached to the support column 3. ia flows. Most of the ground fault current ia flows to the protection line 5 and shifts to a ground fault fault feeder circuit short circuit fault. Thereby, the outflow of the ground fault current ia to the ground 1 is suppressed.
However, depending on the type of support column 3 (for example, concrete column 3A, steel pipe column 3B), there are the following problems.

FIG. 8A is a diagram illustrating a problem when the support column 3 is a concrete column 3A.
In the S-shaped horn method, the discharge of the S-shaped horns 13 and 14 is also applied to the concrete column 3A, although it is instantaneous, from the time when the insulator ridge 7a is generated until the S-shaped horns 13 and 14 start discharging. A high voltage equivalent to the voltage Vb (for example, the distance between the horns 15 is 4.5 mm and the AC is about 11.6 kV) is applied. However, in general, the dielectric breakdown voltage Va of the concrete pillar 3A is lower than the discharge start voltage Vb of the S-shaped horns 13 and 14 (for example, about AC 5 kV), and therefore cannot withstand the applied voltage (≈Vb). Insulation breakdown may occur at a location 16 between the utility pole band and the reinforcing bar in the concrete pillar 3A, the concrete pillar 3A may be damaged, and the ground fault current ia may flow out to the ground 1.

FIG. 8B is a diagram showing a problem when the support column 3 is a steel pipe column 3B having a low ground resistance R1.
Since the ground resistance R1 of the steel pipe column 3B is low, as indicated by an arrow, the ground fault current ia flows to the ground 1 through the steel pipe column 3B during a ground fault. Therefore, the voltage between the horns 15 of the S-shaped horns 13 and 14 does not reach the discharge start voltage Vb and may not operate.
As a technique for solving such problems of FIGS. 8A and 8B, for example, an abnormal voltage protection device described in Patent Document 1 is known.

FIGS. 9A and 9B are configuration diagrams showing a conventional abnormal voltage protection device 20, and FIG. 9A is a diagram showing a usage state of the abnormal voltage protection device 20 and FIG. 9B. FIG. 4 is a circuit diagram of the abnormal voltage protection device 20.
The abnormal voltage protection device 20 is used for the purpose of reducing the discharge start voltage Vb of the S-shaped horns 13 and 14, and includes, for example, two S-shaped horn auxiliary gaps (hereinafter simply referred to as “auxiliary gaps”). It is composed of 21-1 and 21-2. The two auxiliary gaps 21-1 and 21-2 have the same configuration, and are each configured by a series circuit of an arrester 22 as a discharge tube and a varistor 23 made of a zinc oxide element. Mounting brackets 24 and 25 are attached to both ends of each auxiliary gap 21-1 and 21-2, and are used by being mounted between the horns 15 of the S-shaped horns 13 and 14 by the mounting brackets 24 and 25.

  The arresters 22 constituting the auxiliary gaps 21-1 and 21-2 are configured such that the discharge start voltage Vc is lower than the discharge start voltage Vb of the S-shaped horns 13 and 14 (for example, Vc = AC3 kV). ), The discharge start voltage Vb of the S-shaped horns 13 and 14 is reduced by operating as follows.

FIGS. 10 (1) to 10 (4) are diagrams showing an operation image of the auxiliary gaps 21-1 and 21-2 in FIG. 9 when the insulator entanglement occurs.
The operation of the auxiliary gaps 21-1, 21-2 will be described with reference to FIGS. 10 (1) to 10 (4).

  First, in FIG. 10A, when the insulator spiral 7a is generated, the auxiliary gap 21-1 or 21-2 is discharged, and the ground fault current ia flows as indicated by an arrow, and the magnitude of the ground fault current ia. The varistor 23 or arrester 22 is broken at the location 26a. In FIG. 10B, an arc 26b is generated from the damaged portion 26a. In FIG. 10 (3), the arc 26 b generated in FIG. 10 (2) serves as a trigger, the arc 26 b moves to the location 26 c of the S-shaped horns 13, 14, and the horn 15 between the S-shaped horns 13, 14 is Discharge. At this time, the auxiliary gap current disappears in the portion 26d of the auxiliary gap 21-1 or 21-2. Thereafter, in FIG. 10 (4), the arc 26 b transferred in FIG. 10 (3) extends to the location 26 e, and the arc 26 b is completely transferred to the S-shaped horns 13 and 14.

  Thus, the auxiliary gaps 21-1 and 21-2 reduce the discharge start voltage Vb of the S-shaped horns 13 and 14, and the S-shaped horns 13 and 14 when the concrete column 3A is broken down or when the steel pipe column 3B is used. Is prevented from malfunctioning.

No. 4116912 gazette

  However, the conventional abnormal voltage protection device 20 of Patent Document 1 has the following problems (i) and (ii).

(I) Problems when applied to the Shinkansen The difference in the magnitude of the ground fault current ia flowing in the S-shaped horns 13 and 14 at the time of the ground fault between the AC conventional line (AC 22 kV feed) and the Shinkansen (AC 30 kV feed) There is. For example, the ground fault current ia is about 3 kA in the case of an AC conventional line, but is about 10 kA in the Shinkansen, which is more than three times the conventional line. Therefore, when the auxiliary gaps 21-1 and 21-2 are applied to the Shinkansen, there is a concern about dropout of the varistor 23 due to an impact during discharge, scattering of fragments of the arrester 22, and the like, which may cause a fire along the line.

(Ii) Limitations for multiple operations In the substation that supplies the feeding current i to the trolley wire 4, when a ground fault occurs, it is detected and the circuit breaker is opened to stop feeding the feeding current i. It has a function to let you. At that time, the discharge of the S-shaped horns 13 and 14 is also stopped.
Normally, ground faults are often transient due to birds and flying objects. For example, the circuit breaker automatically recloses after 500 ms from the opening of the circuit breaker in the substation, and the feeding current i is supplied. Resume. However, depending on the situation, the ground fault may continue, and in this case, the auxiliary gaps 21-1 and 21-2 also start discharging again.
Therefore, the auxiliary gaps 21-1, 21-2 need to be able to cope with a plurality of discharges. However, in the conventional S-shaped horn gap, the number of auxiliary gaps 21-1, 21-2 is two. It is difficult to cope with three or more discharges. Up to now, it has been dealt with by attaching a plurality of auxiliary gaps 21-1, 21-2, but at present, the attachment of three or more is difficult due to the limitation of the installation space and the like, and takes time and effort.

  The abnormal voltage protection device for a train line in the present invention is disposed in the vicinity of a pair of discharge arc horns attached to one end and the other end of an insulator suspended between a support column and a protection line, respectively. And a discharge auxiliary gap circuit connected between the pair of arc horns.

  A plurality of discharge circuits connected in parallel, each having a discharge start voltage lower than a discharge start voltage of the pair of arc horns; A discharge backup gap connected in parallel to the discharge circuit, having a discharge start voltage lower than a discharge start voltage of the pair of arc horns and higher than a discharge start voltage of the plurality of discharge circuits; I have. The plurality of discharge elements in the plurality of discharge circuits are housed in an insulating case, and the plurality of arcs in the plurality of discharge circuits are outside the insulating case and the pair of arcs. It is arranged directly under the horn.

According to the abnormal voltage protection device for a train track in the present invention, there are the following effects (a) to (e).
(A) The abnormal voltage protection device of the present invention is a method of transferring the arc generated in the arcing line to the arc horn, or the arc generated in the backup gap, and the discharge element is not damaged. There is no fear of splattering and debris scattering, and the risk of fire along the line can be prevented.
(B) According to the above (a), even in a train line through which a large current flows like a Shinkansen, by using the abnormal voltage protection device of the present invention, the discharge start voltage of the arc horn is reduced, and the dielectric breakdown of the concrete column is reduced. In addition, the arc horn can be prevented from malfunctioning when the steel pipe column is used.

(C) In the abnormal voltage protection device of the present invention, a single abnormal voltage protection device can cope with a plurality of discharges by a plurality of arc lines in a plurality of discharge circuits and a backup gap.
(D) Since the plurality of discharge elements are accommodated in the case, the discharge elements can be prevented from being deteriorated due to fouling, and can be prevented from being dropped when damaged.
(E) The above-mentioned (a) to (d) can be expected to further improve the ground fault protection function on the train track.

The block diagram which shows the abnormal voltage protective device 30 of Example 1 of this invention Front view of FIG. Enlarged perspective view of the external appearance of the abnormal voltage protection device 30 in FIG. The perspective view which looked at FIG. 3A from the upper part Plan view of FIG. 3A viewed from above The figure which shows the operation image at the time of normal time (before arc wire burnout) at the time of the insulator entanglement of FIG. The figure which shows the operation | movement image after arc wire burning at the time of the insulator winding occurrence of FIG. The figure which shows the image of the ground fault in the AC train line The figure which shows the image of ground fault protection by S-shaped horn system The figure which shows the problem in case the support pillar 3 is concrete pillar 3A The figure which shows the problem in case the support pillar 3 is the steel pipe pillar 3B with low grounding resistance R1 Configuration diagram showing a conventional abnormal voltage protection device 20 The figure which shows the operation | movement image of the auxiliary | assistant gap 21-1, 21-2 of FIG.

  Modes for carrying out the present invention will become apparent from the following description of the preferred embodiments when read in light of the accompanying drawings. However, the drawings are only for explanation and do not limit the scope of the present invention.

(Configuration of Example 1)
FIGS. 1A and 1B are configuration diagrams showing an abnormal voltage protector 30 for a train line in Embodiment 1 of the present invention. FIG. 1A shows a pair of arc horns 13 and 14 for discharge. The perspective view of the external appearance of the abnormal voltage protective device 30 attached to FIG. 2, and the same figure (b) are the circuit diagrams of the abnormal voltage protective device 30. FIG. FIG. 2 is a front view of FIG. FIG. 3A is an enlarged perspective view of the external appearance of the abnormal voltage protection device 30 in FIG. FIG. 3B is a perspective view of FIG. 3A viewed from above. 3C is a plan view of FIG. 3A as viewed from above.
1 to 3C, the same reference numerals are assigned to elements common to those in the conventional FIGS. 6 to 8B.

  The abnormal voltage protection device 30 according to the first embodiment includes a pair of discharge arcs attached to one end (for example, the upper part) and the other end (for example, the lower part) of the insulator 12, as in the conventional FIG. Attached to horns (for example, S-shaped horns) 13 and 14. The insulator 12 is suspended between the upper arm member 11 attached to the support column 3 and the protective wire 5. A discharge gap 15 a is formed between the horns 15 of the pair of S-shaped horns 13 and 14. An abnormal voltage protection device 30 is attached in the vicinity below the discharge gap 15a.

  Main components of the abnormal voltage protection device 30 are housed in an insulating case 31 such as resin. The case 31 has, for example, a hollow, substantially box shape, and a pair of auxiliary gap terminals 32 and 33 are provided at opposite locations on the upper portion of the box shape. Mounting brackets 34 and 35 are rotatably connected to the pair of auxiliary gap terminals 32 and 33 by bolts and nuts, respectively. The mounting brackets 34 and 35 are formed in an annular shape by a stainless steel band or the like. One mounting bracket 34 is detachably mounted on the outer periphery of the S-shaped horn 13, and the other mounting bracket 35 is also mounted detachably on the outer periphery of the S-shaped horn 14.

  A discharge auxiliary gap circuit 36 is connected between the pair of auxiliary gap terminals 32 and 33. The auxiliary gap circuit 36 includes a plurality of (for example, two) discharge circuits 40-1 and 40-2 and a backup backup gap 45, and the discharge circuit 40-1, the discharge circuit 40-2, and the backup are provided. A gap 45 is connected in parallel. Each of the discharge circuits 40-1 and 40-2 has the same configuration, and includes a plurality of discharge elements (for example, an arrester 41 that is a discharge tube and a varistor 42 that includes a zinc oxide element), and an arc wire 43. The arrester 41, the arc wire 43, and the varistor 42 are connected in series.

  Each of the discharge circuits 40-1 and 40-2 has a discharge start voltage Vc (<Vb) lower than the discharge start voltage Vb (for example, about AC 11.6 kV) of the pair of S-shaped horns 13 and 14. The arc wire 43 is formed of, for example, a metal material that melts at an impulse current of about 8 kA to 10 kA. The discharge gap of the backup gap 45 is lower than the discharge start voltage Vb of the pair of S-shaped horns 13 and 14, and is slightly higher than the discharge start voltage Vc of the discharge circuits 40-1 and 40-2. The start voltage is set to Vd (> Vc, for example, about AC 5 kV).

  The arrester 41 and the varistor 42 in each of the discharge circuits 40-1 and 40-2 are accommodated in the case 31. On the other hand, the arc wire 43 in each of the discharge circuits 40-1 and 40-2 is disposed outside the case 31 and directly below the pair of S-shaped horns 13 and 14, respectively. Each arc wire 43 is preferably inserted into the first insulating tube 43a made of soft resin or the like, that is, covered with the first insulating tube 43a in order to prevent contamination from the outside. Further, the backup gap 45 is disposed outside the case 31 and directly below the pair of S-shaped horns 13 and 14. The backup gap 45 is inserted into the second insulating tube 45a made of soft resin or the like, that is, covered with the second insulating tube 45a, in order to prevent unnecessary discharge due to arc generation at the arc wire 43. Is desirable.

(Operation of Example 1)
FIGS. 4 (1) to 4 (4) are diagrams showing an operation image in a normal time (before the arc wire is burned out) when the insulator entanglement occurs in the abnormal voltage protection device 30 of FIG.
With reference to FIGS. 4 (1) to (4), the normal operation of the abnormal voltage protection device 30 (before the arc wire is burned out) will be described.

  First, in FIG. 4 (1), when the insulator 7a occurs in the insulator 7 in FIG. 7 due to the occurrence of a ground fault, one of the discharge circuits (for example, The arrester 41 and the varistor 42 in 40-1) are discharged. Then, as indicated by the arrow, the ground fault current ia is changed from the S-shaped horn 13 → the mounting bracket 34 → the auxiliary gap terminal 32 → the arrester 41 in the discharge circuit 40-1 → the arc wire 43 → the varistor 42 → the auxiliary gap terminal 33 → It flows along the path of the mounting bracket 35 → the S-shaped horn 14. When the ground fault current ia flows through the arc wire 43, the portion 50a of the arc wire 43 cannot withstand the magnitude of the ground fault current ia and melts.

  In FIG. 4 (2), an arc 50 c is generated at the burned-out location 50 b of the arc wire 43. Since the backup gap 45 is covered with the insulating tube 45a, the generated arc 50c is accurately prevented from shifting to the backup gap 45. In addition, by expanding the space | interval of the arc wire 43 and the backup gap 45, even if the backup gap 45 is not coat | covered with the insulating tube 45a, the transfer to the backup gap 45 of the generated arc 50c can be prevented.

  In FIG. 4 (3), the arc 50 c generated in FIG. 4 (2) serves as a trigger, the arc 50 c moves to the location 50 d of the S-shaped horns 13, 14 and the current in the discharge circuit 40-1 disappears. When the arc 50c moves to the location 50d of the S-shaped horns 13, 14, the discharge gap 15a between the horns 15 of the S-shaped horns 13, 14 is discharged.

  Thereafter, in FIG. 4 (4), the arc 50 c transferred in FIG. 4 (3) extends to the point 50 e at the tip of the horn, and the arc 50 c is completely transferred to the S-shaped horns 13 and 14. Thereby, the arrester 41 and the varistor 42 in the discharge circuit 40-1 are not damaged.

FIGS. 5 (1) to 5 (4) are diagrams showing an operation image after burning of the arc wire when an insulator entanglement occurs in the abnormal voltage protection device 30 of FIG.
With reference to FIGS. 5 (1) to (4), the operation after the arc wire burnout in the abnormal voltage protection device 30 will be described.

  First, in FIG. 5 (1), since the arc wire 43 in the discharge circuit 40-1 has disappeared, the backup gap 45 is discharged, and as shown by the arrow, the S-shaped horn 13 → the mounting bracket 34 → the auxiliary gap. The ground fault current ia flows through the backup gap 45 through the path of the terminal 32 → the backup gap 45 → the auxiliary gap terminal 33 → the mounting bracket 35 → the S-shaped horn 14.

In FIG. 5 (2), an arc 50 f is generated between the gaps of the backup gap 45.
In FIG. 5 (3), the arc 50 f generated in FIG. 5 (2) serves as a trigger, and the arc 50 f moves to the location 50 g of the S-shaped horns 13 and 14. Thereby, the discharge gap 15a between the horns 15 in the S-shaped horns 13 and 14 is discharged.

  Thereafter, in FIG. 5 (4), the arc 50 f transferred in FIG. 5 (3) extends to the point 50 h at the tip of the horn, and the arc 50 f completely transfers to the S-shaped horns 13 and 14.

  Note that the discharge start voltage Vd of the backup gap 45 is set to a value slightly higher than the discharge start voltage Vc of the arrester 41 or the varistor 42. Therefore, at the time of the first discharge, for example, one discharge circuit 40-1 operates as shown in FIG. 4 due to the variation in the discharge start voltage of the component, and at the second discharge, the other discharge circuit 40-2 is illustrated. It operates in the same way as 4. In the third and subsequent discharges after the two arcs 43 in the discharge circuits 40-1 and 40-2 are burned out, the operation is performed as shown in FIG.

(Effect of Example 1)
According to the abnormal voltage protection device 30 of the first embodiment, the following effects (a) to (e) are obtained.
(A) The conventional abnormal voltage protection device 20 of FIG. 9 is a system in which arcs generated at the damaged portions of the arrester 22 and the varistor 23 are transferred to the S-shaped horns 13 and 14. In contrast, in the abnormal voltage protection device 30 according to the first embodiment, the arc generated in the arcuate line 43 in the discharge circuits 40-1 and 40-2, or the arc generated in the backup gap 45 is S-shaped. Since the arrester 41 and the varistor 42 are not damaged, there is no fear of dropping of the varistor 42 or scattering of fragments of the arrester 41, and the risk of fire along the line can be prevented.
(B) According to the above (a), even in a train line where a large current flows like a Shinkansen, by using the abnormal voltage protection device 30 of the first embodiment, the discharge start voltage Vb of the S-shaped horns 13 and 14 can be reduced. It is possible to reduce the dielectric breakdown of the concrete pillar 3A and the malfunction of the S-shaped horns 13 and 14 when the steel pipe pillar 3B is used.

(C) The conventional abnormal voltage protective device 20 of FIG. 9 can cope with only one discharge for each of the S-shaped horn auxiliary gaps 21-1 and 21-2. On the other hand, in the abnormal voltage protection device 30 of the first embodiment, one abnormal voltage protection device 30 is constituted by the two arcs 43 in the discharge circuits 40-1 and 40-2 and the backup gap 45. Thus, it is possible to cope with a plurality of discharges (three or more times).
(D) Since the two arresters 41 and the two varistors 42 are housed in the case 31, the arrester 41 and the varistors 42 can be prevented from being deteriorated due to contamination, and further prevented from being dropped when damaged. it can.
(E) The above-mentioned (a) to (d) can be expected to further improve the ground fault protection function on the train track.

(Modification)
The present invention is not limited to the first embodiment, and various usage forms and modifications are possible. For example, there are the following forms (A) and (B) as usage forms and modifications.

(A) The S-shaped horns 13 and 14 in FIG. 1A can be changed to shapes and structures other than those shown.
(B) In the abnormal voltage protective device 30 of FIG. 1B, if there is a margin in the component storage space in the case 31, three or more discharge circuits 40-1 and 40-2 may be provided. Thereby, it can respond to many earth faults. The case 31 and the mounting brackets 34 and 35 can be changed to shapes and structures other than those illustrated. Furthermore, the lightning protection circuits 40-1 and 40-2 may be changed to a circuit configuration other than that illustrated by adding another discharge element.

2 rail 3 support column 4 trolley wire 5 protective wire 6, 7, 12 insulator 13, 14 S-shaped horn 30 abnormal voltage protection device 31 case 36 auxiliary gap circuit 40-1, 40-2 discharge circuit 41 arrester 42 varistor 43 arc wire 43a First insulating tube 45 Backup gap 45a Second insulating tube

Claims (6)

Discharge disposed near a pair of discharge arc horns attached to one end and the other end of the insulator suspended between the support column and the protective wire, and connected between the pair of arc horns. In an abnormal voltage protection device for a train line equipped with an auxiliary gap circuit for
The auxiliary gap circuit is
A plurality of discharge circuits connected in parallel, each having a discharge element and an arc wire connected in series, each having a discharge start voltage lower than the discharge start voltage of the pair of arc horns;
A backup backup gap connected in parallel to the plurality of discharge circuits, having a discharge start voltage lower than a discharge start voltage of the pair of arc horns and higher than a discharge start voltage of the plurality of discharge circuits. When,
With
The plurality of discharge elements in the plurality of discharge circuits are housed in an insulating case,
The plurality of arc lines in the plurality of discharge circuits are disposed outside the insulating case and directly below the pair of arc horns, respectively.
An abnormal voltage protection device for a train track, characterized in that. The plurality of arc lines are:
It is inserted into the first insulating tube, respectively,
The abnormal voltage protection device for a train line according to claim 1. The backup gap is
It is inserted into the second insulating tube,
The abnormal voltage protective device for a train line according to claim 1 or 2. The plurality of discharge circuits are two discharge circuits.
The abnormal voltage protective device for a train line according to any one of claims 1 to 3. The discharge elements are arresters and varistors,
The arrester, the arc wire, and the varistor are connected in series between the pair of arc horns,
The apparatus for protecting an abnormal voltage of a train line according to any one of claims 1 to 4. The pair of arc horns has two opposing S-shaped arc horns,
An air discharge gap is formed between the two S-shaped arc horns.
The abnormal voltage protection device for a train line according to any one of claims 1 to 5.

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