JP5470523B2 - Overcurrent protection device storage panel - Google Patents

Description

  The present invention relates to a distribution board in which an overcurrent protection circuit breaker connected to a charging line and an SPD connected to the overcurrent protection circuit breaker and absorbing a surge current flowing from the charging line are stored in a conductive casing. It is related with the overcurrent protection equipment storage panel.

  For example, for the purpose of preventing lightning damage caused by direct lightning or induced lightning, the overcurrent protection device storage panel such as distribution board, switchboard or control panel has a transient caused by direct lightning or induced lightning between the overcurrent protection device and the ground. There is a device in which an SPD (Surge Protective Device) is installed as a device that shunts a surge current by limiting a typical overvoltage (see, for example, Patent Document 1).

  FIG. 14 illustrates a conventional distribution board in which an overcurrent protection circuit breaker and an SPD are stored in a conductive casing. This distribution board includes a main overcurrent protection circuit breaker 2 (hereinafter referred to as main MCCB) connected to the charging line 1, and an overcurrent protection circuit breaker 3 (hereinafter referred to as inspection) on the primary side of the main MCCB2. And SPD 4 that absorbs surge current flowing from charging line 1 and is stored in conductive casing 5.

  In this distribution board, a load 7 is connected to the secondary side of the main MCCB 2 via a branch overcurrent protection circuit breaker 6 (hereinafter referred to as a branch MCCB), and the aforementioned SPD 4 and the load 7 must be grounded. is there. Therefore, the ground terminal block 8 is installed in the lower part of the conductive casing 5 in a state of being electrically connected to the casing 5, and the SPD 4 and the ground terminal block 8 are connected by the SPD ground line 9 and the load 7 and the ground are connected. The terminal block 8 is connected to the load ground wire 10, and the ground terminal block 8 is connected to the ground via the ground bus 11.

Utility Model Registration No. 3086902

  By the way, in the above-mentioned conventional distribution board, since the wire diameter of the ground bus 11 is large, the large-diameter ground bus 11 cannot be directly connected to the SPD 4. Therefore, a grounding terminal block 8 is provided at the lower part of the conductive housing 5, and a large-diameter ground bus 11 is connected to the grounding terminal block 8 and a small-diameter SPD grounding wire 9 extending from the SPD 4 is connected to the grounding terminal block 8. The terminal block 8 is used for relaying. In addition, a load ground line 10 from the load 7 is also connected to the ground terminal block 8 in the same manner as the SPD ground line 9.

  On the other hand, in this type of distribution board, in order to achieve optimal overvoltage protection, the wiring length of the connection conductor of SPD4 is required to be 0.5 m or less according to Japanese Industrial Standard (JIS) (JIS). C60364-5-53.534.2.9: See FIG. 53D). That is, as shown in FIG. 14, the sum (a + b) of the length a of the charging side connection conductor of SPD 4 and the length b of the ground side connection conductor of SPD 4 is required to be 0.5 m or less. .

  On the other hand, in the current distribution board, the SPD 4 ground-side connection conductor, that is, the SPD ground line 9 is often 1 m or longer in length, and when a surge current due to lightning strikes, the SPD 4 connection conductor Due to the inductance and the resistance component, the load 7 is charged with the sum of the voltages generated in the respective parts including the limit voltage of the SPD 4, and it is difficult to reliably protect the load 7.

  Therefore, the present invention has been proposed in view of the above-described problems, and the object of the present invention is to reduce the length of the ground side connection conductor of the SPD as much as possible and to ensure the overvoltage protection of the load. It is to provide an overcurrent protection device storage panel.

  As technical means for achieving the above-mentioned object, the present invention is an overcurrent protection circuit breaker connected to a charging line, and is connected to the overcurrent protection circuit breaker to absorb a surge current flowing from the charging line. An overcurrent protection device storage panel in which an SPD is stored in a conductive casing, wherein the first ground terminal block is provided in the conductive casing in a state of being electrically insulated, and the first bus terminal is connected to the ground bus. The SPD is connected to the ground terminal block with the first ground wire, and the second ground terminal block is electrically connected to the conductive casing, and the SPD is connected to the second ground terminal block to which the load is connected. Are connected by a second grounding wire. The SPD in the present invention can be connected to either the primary side or the secondary side of the overcurrent protection circuit breaker.

  In the present invention, a first grounding terminal block electrically insulated from the conductive casing and a second grounding terminal block electrically connected to the conductive casing are provided, and the ground bus is connected. The first ground line connecting the first ground terminal block and the SPD is a current line, and the second ground line connecting the second ground terminal block to which the load is connected and the SPD is a voltage line. As a result, a surge current caused by a lightning strike processed by the SPD flows only in the first grounding line serving as a current line, and the length of the grounding side connection conductor of the SPD becomes substantially zero. As a result, the second ground line, which is a voltage line through which no surge current flows, becomes an equipotential line, and the surge voltage generated in the first ground line is no longer applied to the load, ensuring overvoltage protection of the load. .

  In the present invention, a structure in which the first ground terminal block and the second ground terminal block are arranged in parallel at the lower portion of the conductive casing is desirable. In this way, the wiring connection work can be performed at one place at the bottom of the conductive casing, so that workability can be improved.

  In the present invention, a structure in which the first ground terminal block is disposed close to the SPD is desirable. In this way, the first ground line can be shortened by lengthening the ground bus, and the voltage increase due to the first ground line can be suppressed.

  In the present invention, the SPD is provided with two ground terminals, one ground terminal is connected to the first ground terminal block by the first ground wire, and the other ground terminal is connected to the second ground by the second ground wire. A structure connected to a terminal block is desirable. In this way, it is possible to reliably connect the first grounding wire and the second grounding wire to the respective grounding terminals of the SPD, and to forget to connect one of the connecting wires. Can be prevented.

  In the present invention, a structure in which the second ground terminal block is provided in the electrically conductive casing in an electrically insulated state, and the second ground terminal block is electrically connected to the conductive casing by the third ground wire. Is desirable. If it does in this way, the thing of the same structure as a 1st grounding terminal block can be used for a 2nd grounding terminal block, and cost reduction can be aimed at.

  According to the present invention, the first grounding terminal block electrically insulated from the conductive casing and the second grounding terminal block electrically connected to the conductive casing are provided, and the ground busbar is connected. The first ground wire connecting the first ground terminal block and the SPD becomes a current line, and the second ground wire connecting the second ground terminal block connected to the load and the SPD becomes a voltage line. . As a result, the length of the ground side connection conductor of the SPD becomes substantially zero. As a result, when a surge current due to lightning strikes, the surge current flows only to the first grounding wire that becomes the current line, and the second grounding wire that becomes the voltage line becomes the equipotential line, so the surge current does not flow The surge voltage generated in the first ground line is no longer applied to the load, the overvoltage protection of the load is ensured, and a highly reliable overcurrent protection device storage board can be provided.

In embodiment of the overcurrent protection apparatus storage board which concerns on this invention, it is a schematic diagram which shows the internal structure of a distribution board. In other embodiment of this invention, it is a schematic diagram which illustrates the case where the 1st earthing terminal block is arrange | positioned close to SPD. It is a schematic diagram which illustrates the case where two ground terminals are provided in SPD in other embodiment of this invention. It is a schematic diagram which illustrates the case where SPD is connected to the secondary side of main MCCB in other embodiment of this invention. In other embodiment of this invention, it is a schematic diagram which illustrates the case where the isolation | separation fuse or switch is provided instead of MCCB for inspection. It is a schematic diagram which illustrates the case where SPD is directly connected to main MCCB in other embodiment of this invention. It is a schematic diagram which illustrates the case where SPD is connected to MCCB for branching in other embodiment of this invention. In other embodiment of this invention, it is a schematic diagram which illustrates the case where the 2nd grounding terminal block is provided in the state electrically insulated with the electroconductive housing | casing. In other embodiment of this invention, it is a schematic diagram which illustrates the case where the 1st ground terminal block is divided | segmented into two ground terminal blocks. FIG. 10 is a schematic view illustrating a case where one of the two ground terminal blocks of FIG. 9 is omitted in another embodiment of the present invention. It is a schematic diagram which illustrates the case where the 1st ground terminal block and the 2nd ground terminal block are made common in other embodiment of this invention. In other embodiment of this invention, it is a schematic diagram which illustrates the case where the several distribution panel is provided in series. In other embodiment of this invention, it is a schematic diagram which illustrates the case where a plurality of distribution boards are connected in series and the first grounding terminal block is shared by each distribution board. It is a schematic diagram which shows the internal structure of the conventional distribution board.

  Embodiments of an overcurrent protection device storage board according to the present invention will be described below with reference to the drawings. In the following embodiments, a case where the overcurrent protection circuit breaker and the SPD are applied to a distribution board stored in a conductive casing will be described in detail.

  As shown in FIG. 1, this distribution board includes a main overcurrent protection circuit breaker 22 (hereinafter referred to as main MCCB) connected to the charging line 21 and an overcurrent protection interruption for inspection on the primary side of the main MCCB 22. A structure in which an SPD 24 that is connected via a charger 23 (hereinafter referred to as MCCB for inspection) and absorbs a surge current flowing from the charging line 21 is stored in a conductive casing 25 (hereinafter simply referred to as a casing). It has. In this distribution board, a load 27 is connected to the secondary side of the main MCCB 22 via a branch overcurrent protection circuit breaker 26 (hereinafter referred to as a branch MCCB), and the aforementioned SPD 24 and the load 27 must be grounded. is there. Therefore, this distribution board includes a grounding structure as in the following embodiments.

  In the distribution board of the embodiment shown in FIG. 1, a first grounding terminal block 32 is provided at a lower part of a casing 25 in a state of being electrically insulated from the casing 25 by an insulating material 33, and a ground bus 31 is connected to the distribution board. The SPD 24 is connected to the first ground terminal block 32 by the first ground wire 34, and the second ground terminal block 35 is electrically connected to the casing 25 at the lower part of the casing 25. Provided is a grounding structure in which the load 27 is connected to the second grounding terminal block 35 to which the load grounding wire 30 is connected and the SPD 24 is connected to the second grounding wire 36. The SPD 24 is connected to the primary side of the main MCCB 22 via the MCCB 23 for inspection. The first ground line 34 and the second ground line 36 are connected in common to one ground terminal 37 provided in the SPD 24.

  In this distribution board, a first ground terminal block 32 that is electrically insulated from the casing 25 and a second ground terminal block 35 that is electrically connected to the casing 25 are provided, and a ground bus 31 is provided. The first ground wire 34 connecting the first ground terminal block 32 and the SPD 24 connected becomes a current line, and the second ground wire connecting the second ground terminal block 35 connected to the load 27 and the SPD 24. 36 is a voltage line. Thereby, the length of the ground side connection conductor of the SPD 24 becomes substantially zero. As a result, when a surge current due to a lightning strike flows, the surge current flows only in the first ground line 34 that becomes a current line, and the second ground line 36 that becomes a voltage line becomes an equipotential line and the surge current flows. Therefore, the surge voltage generated in the first ground line 34 is not applied to the load, and the overvoltage protection of the load 27 is ensured.

  This distribution board has a structure in which a first ground terminal block 32 and a second ground terminal block 35 are arranged in parallel at the lower portion of the casing 25. In this way, by connecting the first ground terminal block 32 and the second ground terminal block 35 in parallel to the lower portion of the housing 25, wiring connection work can be performed at one location on the lower portion of the housing 25. Therefore, the workability can be improved.

  In the above embodiment, the case where the first ground terminal block 32 is installed in the lower part of the casing 25 together with the second ground terminal block 35 has been described, but a structure like the embodiment shown in FIG. 2 is also possible. . In the distribution board of this embodiment, the first ground terminal block 42 is disposed close to the SPD 24 and installed in the housing 25 via the insulating material 43. That is, when compared with the distribution board of FIG. 1, the first ground terminal block 42 is disposed close to the SPD 24, whereby the first ground wire 44 can be shortened and the ground bus 41 can be lengthened. As a result, a voltage increase due to the first ground line 44 can be suppressed. In FIG. 2, the same parts as those in FIG.

  In the above embodiment, the case where the first ground lines 34 and 44 and the second ground line 36 are commonly connected to one ground terminal 37 of the SPD 24 has been described. However, as in the embodiment shown in FIG. A simple structure is also possible. In the distribution board of this embodiment, two ground terminals 38 and 39 are provided in the SPD 24, and one ground terminal 38 is connected to the first ground terminal base 32 by the first ground wire 34 and the other ground terminal. 39 is connected to the second ground terminal block 35 by a second ground line 36. As described above, the SPD 24 is provided with the two ground terminals 38 and 39 to which the first ground line 34 and the second ground line 36 are separately connected, whereby the first ground line 34 and the second ground line 36 are provided. The operation of connecting the line 36 to the respective ground terminals 38 and 39 of the SPD 24 can be reliably performed, and it is possible to prevent the connection of one of the connection lines 34 and 36 from being forgotten. In FIG. 3, the same parts as those in FIG.

  In the embodiment of FIG. 1 described above, the case where the SPD 24 is connected to the primary side of the main MCCB 22 via the MCCB 23 for inspection has been described. However, the SPD 24 is connected to the main trunk via the MCCB 23 for inspection as shown in FIG. It is also possible to connect to the secondary side of the MCCB 22. The same applies to the embodiments shown in FIGS. 2 and 3. In FIG. 4, the same parts as those in FIG.

  In the embodiment of FIG. 1, the case where the SPD 24 is connected to the main MCCB 22 via the MCCB 23 for inspection has been described. However, the structure shown in FIGS. 5 to 7 may be used. That is, in the embodiment shown in FIG. 5, instead of the inspection MCCB 23, a structure in which the SPD 24 is connected to the main MCCB 22 via the disconnecting fuse or the switch 53 is illustrated. In the embodiment shown in FIG. 6, a structure in which the inspection MCCB 23 is omitted and the SPD 24 is directly connected to the main MCCB 22 is illustrated. Furthermore, in the embodiment shown in FIG. 7, a structure in which the SPD 24 is connected to the branch MCCB 26 is illustrated. The structure of the embodiment shown in FIGS. 5 to 7 can be similarly applied to the embodiment shown in FIGS. 5 to 7, the same parts as those in FIG.

  Furthermore, in the embodiment of FIG. 1, the structure provided in the housing 25 in a state where the second ground terminal block 35 is electrically connected to the housing 25 has been described. However, as in the embodiment shown in FIG. 8. A structure is also possible. In the embodiment of FIG. 8, the second ground terminal block 45 is provided in the casing 25 in a state of being electrically insulated from the casing 25 by the insulating material 46, and the second ground terminal block 45 is connected to the third ground terminal block 45. The ground wire 47 is electrically connected to the housing 25. By adopting such a structure, both the first ground terminal block 32 and the second ground terminal block 45 are electrically insulated from the housing 25 by the insulating materials 33 and 46, and the housing 25 Since the thing of the same structure provided in can be used, cost reduction can be aimed at. In FIG. 8, the same parts as those in FIG.

  The distribution board of the embodiment shown in FIG. 9 divides the first ground terminal block 42 in the embodiment of FIG. 2 into two as a modification of the embodiment of FIG. 62 is disposed close to the SPD 24 and installed in the casing 25 via the insulating material 63, and the first grounding terminal block 64 is arranged in the lower part of the casing 25 via the insulating material 65. As in the embodiment of FIG. 2, the first ground terminal block 62 and the SPD 24 are connected by the first ground line 66, but the second ground line extending from the second ground terminal block 35 to which the load 27 is connected. 67 is connected to the first ground terminal block 62. Furthermore, the first ground terminal block 64 to which the ground bus 31 is connected and the first ground terminal block 62 are connected by a ground wire 68. Note that. In FIG. 9, the same parts as those in FIG.

  As a modification of the embodiment shown in FIG. 9, the distribution board of the embodiment shown in FIG. 10 omits the first ground terminal block 64 in the embodiment of FIG. Only the terminal block 62 is provided, and a ground bus 41 is connected to the first ground terminal block 62. In FIG. 10, the same parts as those in FIG.

  As a modification of the embodiment shown in FIG. 10, the distribution board of the embodiment shown in FIG. 11 omits the second ground terminal block 35 in the embodiment of FIG. And a structure shared by the first ground terminal block 72 installed in the housing 25. That is, the load 27 is connected to the first ground terminal block 72 by the load ground line 30 and the first ground terminal block 72 is connected to the housing 25 by the third ground line 74 as in the embodiment shown in FIG. The structure is electrically connected to. In FIG. 11, the same parts as those in FIG.

  In the case of these embodiments shown in FIGS. 9 to 11, the length of the ground side connection conductor of the SPD 24 does not become zero, but the first ground terminal blocks 62 and 72 are disposed close to the SPD 24. Since the length of the ground line 66 can be shortened, the length of the ground-side connection conductor of the SPD 24 can be made as small as possible.

  The embodiment shown in FIG. 12 exemplifies a case where a plurality (three in the figure) of distribution boards in the embodiment of FIG. In the embodiment shown in FIG. 12, the ground bus 31 is individually connected to the first ground terminal block 32 of each distribution board. However, as in the embodiment shown in FIG. The first ground terminal block 82 installed in the casing 25 is made common to each distribution board, and the first ground terminal block 82 and the SPD 24 of each distribution board are connected by the first ground line 34. Connected. In this embodiment, the second ground terminal block 35 is connected by the same potential line 84, but this same potential line 84 is not always necessary. In FIG. 12 and FIG. 13, the same parts as those in FIG.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

21 Charge line 22, 23 Overcurrent protection circuit breaker 24 SPD
25 Conductive housing 27 Load 31 Ground bus 32 First ground terminal block 34 First ground wire 35, 45 Second ground terminal block 36 Second ground wire 38, 39 Ground terminal 47 Third ground wire

Claims (6)

  An overcurrent protection circuit breaker connected to the charging line and an SPD that is connected to the overcurrent protection circuit breaker and absorbs surge current flowing from the charging line in a conductive housing. The first grounding terminal block is electrically insulated from the conductive casing, and the SPD is connected to the first grounding terminal block to which the ground bus is connected by the first grounding wire. In addition, a second grounding terminal block is provided in an electrically connected state to the conductive casing, and the SPD is connected to the second grounding terminal block to which a load is connected by a second grounding wire. The overcurrent protection device storage panel is characterized.   The overcurrent protection device storage panel according to claim 1, wherein the first ground terminal block and the second ground terminal block are juxtaposed on the lower portion of the conductive casing.   The overcurrent protection device storage panel according to claim 1, wherein the first ground terminal block is disposed close to the SPD.   The SPD is provided with two ground terminals, one ground terminal is connected to the first ground terminal block by the first ground wire, and the other ground terminal is connected to the second ground terminal block by the second ground wire. The overcurrent protective device storage panel according to any one of claims 1 to 3, which is connected.   The second ground terminal block is provided in the conductive casing in an electrically insulated state, and the second ground terminal block is electrically connected to the conductive casing by a third ground wire. The overcurrent protection apparatus storage panel as described in any one of -4.   The overcurrent protection device storage panel according to any one of claims 1 to 5, wherein the SPD is connected to either the primary side or the secondary side of the overcurrent protection circuit breaker.

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