JPH11205947A - Duct with wire passing-through holes for switchboard and switchboard employing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a duct with wire passing-through holes for a switchboard which facilitates treatment of excessive lengths of wires connected to apparatuses in the switchboard. SOLUTION: A duct 10 with wire passing-through holes for a switchboard has partition plates 2 and 3 with wire passing-through holes 8 by which the inside of the duct is partitioned in a longitudinal direction and attachment holes 9 for fixing the duct. As the inside of the duct is partitioned into a central neatly arranged wire passage 5 and 1st and 2nd excessive wire passages 6 and 7 provided on the left and right sides of the central neatly arranged wire passage 5, the excessive lengths of branch wires branched into the left and the right sides can be treated without the interference of main wires in the central neatly arranged wire passage 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a duct with a wiring hole for a switchboard and a switchboard using the same.

[0002]

2. Description of the Related Art Conventional ducts with through holes include:
There is disclosed a commercial product in which the inside of a duct can be divided into two parts by a duct partition plate and the electric wires can be interchanged by a through hole. For example, there is a publication in a catalog of Seiwa Electric Co., Ltd.

[0003] As a prior art switchboard using the duct with the through hole, there is one as shown in FIG. The switchboard 50 shown in FIG. 11 includes a duct with a through hole (hereinafter, duct) 11 attached to the casing 40, and a plurality of in-panel devices 20, 21, 22, 23, and 24, from outside the panel. Many electric wires
Pass the 30 through the wire passage of the duct 11, and process the extra length of the wire branched through the wire hole of the duct 11 in the middle of the wire passage
(A process of providing a bend in the electric wire), and a surplus electric wire subjected to the process.
35 is a configuration that is wired to the equipment in each panel. The duct 11 is divided into two passages, a rectifying electric wire passage 15 and a surplus electric wire passage 16. In the rectifying electric wire passage 15, a rectifying electric wire 36 as a main line obtained by collecting and rectifying the electric wires 30 is wired. aisle
At 16, a surplus electric wire 35 as a branch line branched from the main line and subjected to extra length processing is wired, and the electric wire 30 is connected to each of the in-panel devices 20 to 24.
It is connected to the.

[0004]

However, the above-mentioned conventional duct with a through hole has only two electric wire passages, namely, a rectified electric wire passage and a surplus electric wire passage, which are divided into two parts. There is a problem in that, when a large number of the in-panel devices are arranged and the branch lines are subjected to extra length processing and are wired from the through holes, it is difficult to carry out the extra length processing work for one of the right and left branch lines. That is, as shown in FIG. 11, if the rectifying wire passage 16 is applied to the left side for the left in-panel devices 20, 21, 22, and 23, which are arranged more than the right side, the right inner Equipment 24
The main line of the rectifier electric wire passage 15 becomes an obstacle in the branch line to be wired, and the main line in the rectifier electric wire passage 15 and the surplus electric wire 35 of the branch line may be entangled, so that the extra length processing work is difficult. become.

[0005] As a result, in a switchboard using a duct with a through hole according to the prior art, the extra length processing work becomes a bottleneck,
Further, maintenance work is also difficult to use, which leads to problems of productivity and maintainability of the switchboard. On the other hand, the housing of the switchboard 50
Mounting screw when duct 11 is mounted on 40 (not shown)
Since the screw head and the like are exposed, there is a possibility that mainly the rectifying wire 36 in the duct may be damaged. As a result, in a switchboard using a duct with a through hole according to the related art, the electric wires are particularly damaged with the lapse of time, which leads to a problem of the reliability of the switchboard.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a duct with a through hole for a switchboard which facilitates a work of processing excess length of an electric wire to be connected to a device inside the switchboard. Another object of the present invention is to provide a duct with a through hole for a switchboard which can prevent damage to electric wires in the duct of the switchboard.
On the other hand, another object is to provide a switchboard using a duct with a wiring hole for a switchboard, which facilitates extra length processing work, facilitates maintenance work, and improves productivity and maintainability. It is in. Still another object is to provide a switchboard using a duct with a through hole for a switchboard which is highly durable and reliable, in which electric wires in the duct are prevented from being damaged.

[0007]

According to the present invention, there is provided a distribution board duct having a wiring hole for a distribution board, comprising a partition plate having a wiring hole for partitioning the inside of the duct in a longitudinal direction, and a mounting hole for fixing the duct. In the duct with the through hole, the partition plate with the through hole is configured to divide the inside of the duct into three passages of a central rectifying wire passage and first and second extra-long electric wire passages on the left and right sides of the central rectifying wire passage. It is a partition.

[0008] Another characteristic of a duct with a wiring hole for a switchboard is that the wiring for the switchboard has a mounting hole and a number of wiring holes juxtaposed in the longitudinal direction and has a wire passage formed therein. In the duct with holes, the duct with the through holes for the switchboard,
It is another object of the present invention to provide a wire protection partition that separates the mounting hole from the wire passage.

A feature of the switchboard using the duct having a through hole for the switchboard according to the present invention is that a large number of electric wires from outside the panel are accommodated in a wire passage formed in a longitudinal direction, and the above-mentioned wire passage is formed in the wire passage. A power distribution panel using a duct with a distribution hole for a power distribution panel for rectifying a main line of an electric wire, processing the length of the branch line, and wiring the processed branch line to a device inside the panel from the through hole. The duct with a through hole has a partition plate with a through hole that divides the inside of the wire passage into a central rectifying wire passage and first and second extra-long wire passages on the left and right sides of the central rectifying wire passage,
The main line is rectified in the central rectifying wire passage, and the branch line is subjected to extra length processing in the first and second extra-long electric wire passages.

Another feature of the switchboard using the duct with the through holes for the switchboard is that a large number of wires from outside the board are accommodated in a wire passage formed in the longitudinal direction, and are arranged in the wire passage. A distribution panel using a distribution panel duct with a through hole fixed by mounting screws, wherein the duct with a distribution panel through hole has an electric wire protection partition for isolating between the mounting screw and the electric wire passage. It has a board.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a duct with a through hole for a switchboard according to an embodiment of the present invention. FIG. 2 is a view showing a cross section of the duct with a wiring hole for a switchboard of FIG. 1. In FIGS. 1 and 2, a duct (hereinafter referred to as a “duct”) 10 having a distribution hole for a switchboard is provided with a plurality of mounting holes 9 for fixing the duct 10 and a plurality of passages juxtaposed in the longitudinal direction of the left and right side surfaces. A duct main body 1 having a wire hole 8, and fixed inside the duct main body 1 so as to extend in the longitudinal direction. A first partition plate 2 and a second partition plate having a large number of through holes 8 arranged in the longitudinal direction, which partition into three electric wire passages, one extra long electric wire passage 6 and the second extra long electric wire passage 7. It is composed of a partition plate 3 and a cover 4.

When the duct 10 having the above structure is used for a switchboard, a large number of electric wires coming from outside the panel are connected to the duct 10.
, Wiring to a number of in-panel devices arranged on the left and right of the duct 10 inside the switchboard. That is, duct 10
Passes a main line (i.e., a rectified electric wire) of a large number of the electric wires through the central rectified electric wire passage 5 of the duct 10, and branches a branch line (i.e., an extra-long electric wire) branched from the main line into a first extra-long electric wire passage 6 or the second extra-long wire passage 7. In other words, the duct 10 includes the first partition plate 2 and the second partition plate 3.
The central rectifying wire passage 5 is formed at the center, and the extra stranded electric wire passages 6 and 7 for applying extra length processing to the branch wires to be connected to the many in-panel devices arranged on the left and right are formed. 5
The branch lines formed on the left and right of each of the left and right sides and wired to each of the in-panel devices disposed on the left are subjected to extra length processing in the first extra-long electric wire passage 6 on the left, and the respective in-panel devices disposed on the right. The branch line to be wired to is configured so that the excess length can be processed in the second excess length electric wire passage 7 on the right.

[0013] With this configuration, the entanglement (ie, mutual interference) between the main line and the branch line passing through the same duct (ie, the same electric wire passage) is avoided, and the branch line is not hindered by the main line. Since the extra length processing work can be performed independently, the wiring workability is improved. In addition, since the main line and the branch line are clearly separated, there is an advantage that maintenance work of each electric wire and each in-panel equipment performed later can be easily performed. Therefore, according to the configuration of the above-described embodiment, there is provided a duct with a through hole for a switchboard, which facilitates a work of processing excess length of an electric wire to be connected to a device in the switchboard.

Next, another embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG. 3 and 4, a duct 10a has a plurality of mounting holes 9 for fixing the duct itself, and a duct body 1 having a plurality of through holes 8 arranged side by side in the longitudinal direction on the left and right side surfaces. The duct body 1 is fixed to the inside of the duct body 1 so as to extend in the longitudinal direction, and the inside of the duct body 1 is connected to the central rectifying wire passage 5 and the first extra-long wire passages 6 and 2 on the left and right sides of the central rectifying wire passage 5. The cover 4 includes a partition plate 2 a having a plurality of through holes 8 arranged side by side in the longitudinal direction to partition into three electric wire passages with an extra-long electric wire passage 7.

The duct 10a according to the present embodiment has one partition plate 2
a, three central rectification electric wire passages 5, a first extra-long electric wire passage 6
And a second extra-long electric wire passage 7. Therefore, the present configuration including one partition plate 2a has an advantage that it is simplified as compared with the duct 10 of the above-described embodiment. Further, the partition plate 2a has a configuration in which the central rectifying wire passage 5 has a substantially V-shape that wide opens upward. This substantially V-shaped configuration is used for the central rectifying wire passage 5,
While securing the required electric wire occupied space (or equal distribution of passage space) of the first extra-long electric wire passage 6 and the second extra-long electric wire passage 7, all the through holes 8 formed in the partition plate 2a are removed. Since it can be turned upward when the cover 4 is removed,
There is an advantage that the work of penetrating the branch line into the through hole 8 of the partition plate 2a is facilitated.

Further, the partition plate 2a has a configuration in which mounting holes 9a are provided at the same positions as a plurality of mounting holes 9 for fixing the duct 10a to a housing 40 of a switchboard (not shown). As shown in FIG. 4, the present configuration in which these mounting holes 9 and 9 a overlap each other has a mounting screw 41 and mounting holes 9 and 9.
a through the female screw 42 of the housing 40, the duct 10a
Since the partition plate 2a is also fixed with the mounting screws 41, the advantage that the partition plate 2a is fixed to the duct 10a or the partition plate 2a, which is generally made of a synthetic resin, with respect to aging or temperature change. Have. According to the configuration of the second embodiment, the duct with the through hole for the switchboard which facilitates the work of processing the extra length of the electric wire to be wired to the in-panel equipment of the switchboard and also facilitates the operation of penetrating the branch line into the through hole is provided. Provided.

Next, another embodiment of a duct with a through hole for a switchboard according to the present invention will be described with reference to FIGS. The duct 10b of the third embodiment shown in FIGS.
A duct body 1b having a plurality of mounting holes 9 for fixing the duct itself, and having a large number of through-holes 8 juxtaposed in the longitudinal direction of the left and right side surfaces;
Is extended in the longitudinal direction and is engaged with the inside of the duct body 1.
b, the central rectifying wire passage 5 and the central rectifying wire passage 5
A partition plate 2b having a large number of through holes 8 which are divided into three left and right first extra-long wire passages 6 and a second extra-long wire passage 7; , Cover 4
It is composed of And the duct 10b of the present embodiment
Is a single partition plate 2b, which allows the inside of the duct to pass through the central rectifying wire passage 5, the first extra-long wire passage 6, and the second extra-long wire passage 7
And three electric wire passages. further,
As shown in FIG. 6, the partition plate 2b of this embodiment is provided with a mounting hole 9, that is, a mounting screw 41 and a washer 43 for fixing the duct 10b inserted into the mounting hole 9 and a central rectifying wire passage. 5, an electric wire protection partition is formed to be isolated from each of the first extra-long electric wire passage 6 and the second extra-long electric wire passage 7. In other words, the duct 10b forms the three above-mentioned electric wire passages partitioned by the partition plate 2b, and covers the mounting hole 9 and the mounting screws 41 and washers 43 inserted into the mounting hole 9 to form each of the electric wires. This is a configuration in which a protection passage 60 for protecting an electric wire laid in the passage from the mounting screw 41 and the washer 43 is formed.

Since the partition plate 2b has an isolation function for preventing damage to the wires routed in the respective wire passages, the surface 61 of the partition plate 2b exposed to the central rectifying wire passage 5 is provided.
On the surfaces 62, 63 of the partition plate 2b exposed to the first extra-long electric wire passage 6 and the second extra-long electric wire passage 7, not only the through holes 8 that may lead to electric wire damage, but also of course. It is desirable that no protrusion or the like is formed. Generally, since the mounting hole 9 is provided at the center bottom surface of the duct main body 1b facing the central rectifying wire passage 5, the mounting hole 9 and at least the central rectifying wire passage 5 of each wire passage are connected. Will be isolated. In addition, the partition plate 2b of this embodiment has a configuration in which the central rectifying wire passage 5 has a substantially V-shape that opens wide upward, and has an advantage that the work of penetrating the branch line is facilitated.

The above configuration in which the partition plate 2b forms the wire protection partition plate has the advantage that damage caused by the mounting screw 41, the washer 43, etc. of the electric wire wired in the duct 10b can be prevented. In particular, the abrasion between the electric wire and the mounting screw, which occurs with time, is prevented, and the effect of improving the durability reliability of the switchboard using the duct 10b is obtained. Further, the partition plate 2b, as shown by the enlarged engagement portion in FIG.
In this configuration, the partition plate engaging portion 71 and the main body engaging portion 72 are engaged with the duct main body 1b. The configuration of the full engagement is as follows.
This has the advantage that the operation of fixing the partition plate 2b is simplified. Therefore, according to the configuration of the third embodiment, the wiring hole for the switchboard which can facilitate the processing of the excess length of the wires to be connected to the devices in the switchboard and prevent the wires in the duct of the switchboard from being damaged. Provided ducts are provided.

Next, a fourth embodiment of a duct with a through hole for a switchboard according to the present invention will be described with reference to FIGS. 7 and 8, the duct 10c of the fourth embodiment is different from the casing 10 of the switchboard (not shown) in that the duct 10c itself is provided.
A duct body 1c having a substantially U-shaped cross-section, having a plurality of mounting holes 9 on the bottom surface for fixing to the bottom surface, and having a plurality of through-holes 8 arranged on the left and right side surfaces in a longitudinal direction, 1
c, and a wire protection partition plate 2c which engages with the duct body 1c inside the duct and partitions the inside of the duct into a wire passage 55 and a protection passage 60 to form a duct having a substantially square cross section. doing. And the electric wire passage 55 is
A protection passage 60 is inserted into the mounting hole 9 and formed in the housing 40 through the duct 10c.
(The duct main body 1c) is fixed to accommodate a mounting screw 41 and a washer 43, and a passage is formed to protect an electric wire laid from the mounting screw 41 and the washer 43 into the electric wire passage 55. is there.

In other words, the feature of the duct 10c of this embodiment is that the duct 10c has an electric wire protection partition plate 2c for isolating between the mounting hole 9 and the electric wire passage 55. Therefore,
Since the electric wire protection partition plate 2c has an isolation function for preventing the electric wires laid in the electric wire passage 55 from being damaged, the electric wire passage 55
The surface 64 of the wire protection partition 2c exposed to
It is desirable that a configuration is not provided in which the through-hole 8 or the projection or the like that may lead to damage to the electric wire is not formed. According to the configuration of the fourth embodiment, there is provided a duct with a through hole for a switchboard which prevents damage to electric wires in the duct of the switchboard.

Next, a duct with a through hole for a switchboard according to a fifth embodiment of the present invention will be described with reference to FIG. The duct 10d of the fifth embodiment shown in FIG. 9 has a configuration in which the wire protection partition 2c of the duct 10c of the fourth embodiment that partitions the inside of the duct is replaced with the partition 2d, and the other configuration is the same as that of the fifth embodiment. The configuration is the same as that of the fourth embodiment. That is, the duct 10d
A duct body 1c having a substantially U-shaped cross section, a cover 4c covering the duct body 1c, engaging the duct body 1c while extending the inside of the duct in the longitudinal direction, and forming a rectifying wire passage 5a and a surplus length inside the duct. It is composed of a partition plate 2d that partitions the two electric wire passages of the electric wire passage 6a and the protection passage 60, and forms a duct having a substantially square cross section.

The straightening wire passage 5a forms a passage through the main line laid inside the duct, and the extra-long electric wire passage 6a forms a passage through a branch line branched from the main line and subjected to extra-length processing. The protection passage 60 has a mounting hole 9 and a mounting screw 41 (and a washer 43) inserted into the mounting hole 9 for fixing the duct 10c (the duct body 1c) to the housing 40.
Are formed in the rectifier electric wire passage 5a and the extra-long electric wire passage 6a so as to be isolated from the main line and the branch line.

That is, one partition plate 2d of the duct 10d of the present embodiment separates the rectifying wire passage 5a and the extra-long wire passage 6a and separates the main line and the branch line from the mounting screw 41. It is. Accordingly, the partition plate 2d, which also serves as the electric wire protection, is provided with the rectifying electric wire passage 5a and the extra-long electric wire passage 6a.
Has a separating function for preventing damage to the electric wires wired to the rectifying electric wire passage 5a and the extra-long electric wire passage 6a. It is desirable that there are no formed communication holes 8 or projections.

According to the configuration of the fifth embodiment, there is also provided a duct with a through hole for a switchboard which prevents damage to electric wires in the duct of the switchboard. The engaging configuration between the partition plate and the duct body of the fourth and fifth embodiments is the same as the configuration shown in the enlarged engagement portion of FIG. 6, and the partition plate engaging portion of the partition plate. It is configured to engage with the main body engaging portion 72 of the duct main body.

Next, a description will be given of a switchboard using the above-described duct with a wiring hole for a switchboard according to the present invention with reference to FIG. FIG. 10 is a perspective view showing a switchboard using a duct with a through hole for a switchboard according to one embodiment of the present invention. The switchboard 50 shown in FIG. 10 has a configuration in which a large number of electric wires 30 coming from outside the panel are wired to the equipment in each panel, using the duct 10b as the duct with the through holes for the switchboard of the third embodiment described above. It is.

In FIG. 10, a switchboard 50 includes a housing 40,
A duct 10b attached to the casing 40, and a plurality of in-panel devices arranged on the left side of the duct 10b and attached to the casing 40
20, 21, 22, 23, a plurality of in-panel devices 24, 25, 26, which are disposed on the right side of the duct 10b and are attached to the housing 40, and a number of electric wires 30 coming from outside the panel. ing. The large number of electric wires 30 coming from outside the panel are guided to the central rectifying electric wire passage 5 of the duct 10b and become the rectifying electric wires 36, and are branched left and right from the rectifying electric wires 36 to become the surplus electric wires 35 which have been subjected to extra processing. ,
Wired to the left and right internal devices.

In this embodiment, a switchboard 50 having seven in-panel devices is shown, but 30 to 150 (an average of 100) in-panel devices are arranged in a commonly used switchboard 50. Therefore, if the duct 10b has the first extra-long electric wire passage 6 and the second extra-long electric wire passage 7 on the left and right, the extra-long electric wire 35 can be processed smoothly, and The entanglement between the electric wire 35 and the rectifying electric wire 36 does not occur. Therefore, it becomes easy to manufacture the switchboard 50 having a large number of in-panel devices. Furthermore, since the extra-long wires 35 and the rectifying wires 36 are clearly distinguished from each other, it is easy to remove connection wires from the in-panel equipment when repairing individual in-panel equipment, and maintenance of the distribution board 50 is required. It will be easy.

On the other hand, in the enlargement of the portion A in FIG.
The partition plate 2b of 10b covers the mounting screw 41 and the washer 43 fixing the duct main body 1b to the housing 40, thereby preventing the mounting screw 41 and the washer 43 from damaging the rectifying wire 36. According to the configuration of the above-described embodiment, a power distribution panel using a duct with a wiring hole for a power distribution panel can be provided which facilitates extra length processing work, facilitates maintenance work, and improves productivity and maintainability. Is done. Further, there is provided a switchboard using a duct with a through hole for a switchboard, which can prevent the electric wires in the duct from being damaged and ensure the durability reliability.

[0030]

The duct with a through hole for a switchboard according to the present invention has an effect of being easy to use and capable of being used with ease because the extra length processing operation is easy and the electric wire to be wired is not damaged. On the other hand, the switchboard using the duct with the through holes for the switchboard according to the present invention, the extra length processing work in the duct is easy,
In addition, since the maintenance work of the electric wires in the duct is easy to perform, there is an effect that the productivity and handleability of the switchboard are improved. In addition, there is an effect that damage to the electric wires in the duct is prevented and durability durability of the switchboard is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a duct with a through hole for a switchboard according to an embodiment of the present invention.

FIG. 2 is a view showing a cross section of the duct with a through hole for a switchboard of FIG. 1;

FIG. 3 is a perspective view showing a duct with a through hole for a switchboard according to another embodiment of the present invention.

FIG. 4 is a view showing a cross section of the duct with a wiring hole for a switchboard of FIG. 3;

FIG. 5 is a perspective view showing a duct with a through hole for a switchboard according to a third embodiment of the present invention.

FIG. 6 is a view showing a cross section of the duct with a through hole for a switchboard of FIG. 5;

FIG. 7 is a perspective view showing a duct with a through hole for a switchboard according to a fourth embodiment of the present invention.

FIG. 8 is a view showing a cross section of the duct with a wiring hole for a switchboard of FIG. 7;

FIG. 9 is a sectional view showing a duct with a through hole for a switchboard according to a fifth embodiment of the present invention.

FIG. 10 is a perspective view showing a switchboard using a duct with a through hole for a switchboard according to one embodiment of the present invention.

FIG. 11 is a perspective view illustrating a switchboard using a conventional duct with through holes.

[Explanation of symbols]

1, 1b, 1c ... duct body, 2 ... first partition plate, 2a,
2b, 2d: partition plate, 2c: electric wire protection partition plate, 3: second
Partition plate, 4, 4c ... cover, 5 ... central rectification wire passage,
5a, 15: rectifier wire passage, 6: first extra-long wire passage, 6
a, 16: extra-long electric wire passage, 7: second extra-long electric wire passage, 8 ...
Through holes, 9, 9a ... Mounting holes, 10, 10a, 10b, 10c, 10d
… Duct with duct holes for distribution board, 11… Duct with duct holes, 20,21,22,23,24,25,26… In-panel equipment, 30
... Electric wire, 35 ... Extra long wire, 36 ... Rectified wire, 40 ... Housing, 41 ...
Mounting screw, 42 ... female thread, 43 ... washer, 50 ... switchboard,
55 ... wire passage, 60 ... protection passage, 61, 62, 63, 64, 65, 66 ... surface, 71 ... partition plate engagement site, 72 ... main body engagement site.

Claims (5)

[Claims] 1. A duct with a through hole for a switchboard having a partition plate with a through hole for partitioning the inside of the duct in the longitudinal direction and a mounting hole for fixing the duct, wherein the partition plate with the through hole is A duct with a through hole for a switchboard, wherein the inside of the duct is divided into three passages: a central straightening wire passage and first and second extra-long wire passages on the left and right of the central straightening wire passage. 2. The partition plate with through holes according to claim 1, wherein said partition plate with through holes forms an electric wire protection partition plate for isolating between said mounting hole and at least said central rectifying electric wire passage among said electric wire passages. A duct with a wiring hole for a switchboard, characterized in that: 3. A duct with a through hole for a switchboard having a mounting hole and a plurality of through holes arranged in parallel in a longitudinal direction and having a wire passage formed therein, wherein the duct with a through hole for a switchboard. A wiring hole duct for a switchboard, comprising a wire protection partition separating the mounting hole and the wire passage. 4. A plurality of electric wires from the outside of the panel are accommodated in an electric wire passage formed in a longitudinal direction, and the main wire of the electric wire is rectified in the electric wire passage, and a branch wire is subjected to extra processing. A distribution panel using a distribution panel duct with a through hole for wiring from a branch hole to a device inside the panel, wherein the distribution panel duct with a through hole has a central rectifying wire passage inside the wire passage. A partition plate with a through hole for partitioning the central rectifying electric wire passage into first and second extra-long electric wire passages on the left and right, the main line is rectified in the central rectifying electric wire passage, and the branch line is A switchboard using a duct having a through hole for a switchboard, wherein the excess length is processed in the first and second extra-long electric wire passages. 5. A duct having a through hole for a switchboard, which accommodates a large number of wires from outside the board in wire passages formed in the longitudinal direction and is fixed by mounting screws provided in the wire passages. The switchboard used, wherein the duct with a through hole for the switchboard is a duct with a through hole for a switchboard, characterized by having a wire protection partition plate that separates between the mounting screw and the wire passage. Switchboard.