JP2000295754A - Low-voltage branching device with built-in fuse - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-voltage branching device where a fuse is mounted at the branch point, in the same dimension as an underground low-voltage branching device without a fuse. SOLUTION: For an underground low-voltage branching device, the brancher body composed of a branch conductor for relaying and connecting low-voltage distribution lines wired underground and branching each cable to distribute electricity to consumers, a branch terminal for cable connection connected to this, and others is stored in a box-shaped hand hole. At this time, the connecting conductor of the branch terminal is composed of a common conductor 41 and a independent conductor 42, and connections 52 and 53 capable of mounting and removal of a fuse 50 are made at the common conductor 41 and the independent conductor 42, and a fuse 50 is mounted them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-voltage branching device for branching and distributing power to a customer by relaying a low-voltage distribution line of underground wiring.

[0002]

2. Description of the Related Art In recent years, distribution lines have been buried underground instead of telephone poles in response to demands for beautiful cityscapes.

FIG. 7 shows a system diagram of an underground low-voltage distribution line using a low-voltage branching device. One or several low-voltage branching devices 33 are connected from the secondary side of a transformer 31 by an underground distribution cable 32. They are connected in series, branched from each of the low-voltage branching devices 33, and distributed to a plurality of customers by branch cables 34.

FIGS. 3 to 5 show the structure of the low-pressure branching device. FIG. 3 is a front sectional view, FIG. 4 is a side sectional view, and FIG. 5 is a plan view.

[0005] In these figures, reference numeral 1 denotes a branch body, and four phases of u-phase, v-phase, w-phase, and o-phase are mounted and supported in parallel on a mounting bracket 2, and a box-shaped waterproof dome 4 is covered from above. During flooding, a pool of air is formed in the contact area to prevent flooding. Reference numeral 5 denotes a concrete box-shaped handhole, which is buried underground on the sidewalk surface and houses a branching device in the box.

FIGS. 6A and 6B show the detailed structure of the branch body 1, wherein FIG. 6A is a plan view, FIG.
Is a bottom view.

Reference numeral 11 denotes a branch conductor, which can be connected to the branch cable 14 by tightening the branch terminal 12 with a connection bolt 13. The connection portion is insulated by a rubber mold 15 except for a connection portion. And is fixed by fixing bolts 17. Reference numeral 18 denotes a connection cover that protects the branch terminal 12 and the branch cable 14, 19 denotes a watertight band that presses the connection cover 18 against the branch cable 14 to prevent water from entering the connection part, and 20 denotes a connection part of the branch conductor from dust and water. It is a waterproof cap to protect. Protrusions 2 for mounting on the mounting bracket 2 of the branching device are provided at both ends of the fixing bracket 16.
1 is formed. 22 is a branch terminal 1 connected to the branch conductor 11
2 is a connector formed by assembling a large number of resilient contact pieces interposed in order to reliably connect the two electrically.

The watertight band 19 and the waterproof cap 20
The waterproof dome 4 is provided for double protection in addition to the waterproof effect of the waterproof dome 4 to enhance the waterproof reliability of the connection portion of the branch terminal 12.

The branch terminal 12 has a branch cable 14 having a sectional size of 38 mm ² , 60 mm ² , 100 mm ² , 200 m.
In order to connect m ² , the cable mounting compression connection portion is prepared for each size corresponding to the cable size.

[0010]

As described above, as described above,
The conventional low-voltage branching device is directly branched from a branch conductor to a branch terminal and distributed to each customer, and has no fuse inserted, so there is no protection against short-circuit current or overcurrent. For this reason, in the event of an accident, the cut-out fuse connected to the primary side of the transformer is blown, and all customers below the transformer are cut off, so that the impact of the accident has a wide range. .

However, the structure of the contact portion between the conventional fuse and the connecting conductor for holding and connecting the fuse is composed of a complicated structure such as a tightening structure or a clip structure, and a branch terminal is connected to one of the connecting conductors. In order to achieve this, the shape of the branch conductor becomes complicated and large, and as an underground type low-voltage branching device, replacement of the fuse when the fuse is blown is extremely inconvenient, and there is a problem in maintenance and inspection management. Since they are not practical, those without fuses are used.

When a fuse is required, there is also a low-voltage branch box installed on the ground where a low-voltage branch device is installed on the ground and a wire fuse is mounted at a branch point. However, this low-voltage branch box is mainly mounted on a sidewalk. The installation and the size are quite large, so they are not welcomed in terms of safety and environmental improvement.

The problem to be solved by the present invention is to solve the problem caused by the conventional underground type low-voltage branching device without a fuse and to provide a low-voltage branching device having the same size as the conventional one and having a fuse mounted at a branch point. That is.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an underground buried low-voltage branching device according to the present invention includes a branch conductor that relays a low-voltage distribution line of an underground wiring and branches and distributes the power to a customer. In a submerged low-voltage branching device in which a branch body composed of branch terminals for cable connection to be connected is housed in a box-shaped handhole, the connection conductor of the branch terminal is configured by a common conductor and an independent conductor, A branch circuit is electrically configured by forming a detachable connection portion between the common conductor and the independent conductor where a fuse can be attached and detached, and attaching the fuse to the connection portion.

In this device, the fuse connection portions of the common conductor and the independent conductor are each formed in a cylindrical shape, and the elastic conductors which are in contact with the inner surface of the cylinder are mounted, and the cylindrical connection portions are formed at both ends of the fuse. Electrical insertion / removal is enabled by inserting and removing the fuse linearly.

According to the present invention, since the fuse is mounted at the branch point of the low-voltage branch device, the distribution line from the low-voltage branch device to the customer can be protected.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to embodiments shown in the drawings.

1 and 2 show an embodiment of the present invention. FIG. 1 is a front sectional view of a main part of a branch body, FIG. 2 (a) is a front view of a fuse, and FIG. 2 (b) is a plan view.

As shown in FIG. 1, the branch body of the present invention has substantially the same outer shape as that of a conventional branch body. The branch conductor is constituted by a common conductor 41 and an independent conductor 42, and these are separated by a predetermined distance. And the cylindrical portions 43 and 44 are drilled so that the center line is located on the same line in each conductor, and a cylindrical fuse 50 is mounted on the cylindrical portions 43 and 44 to electrically connect the common conductor 41 and the independent conductor 42 to each other. It is configured to be connected to.

The fuse 50 has the same external dimensions from a small capacity of about 30 A to a large capacity of about 400 A.
Both are compatible.

The above-mentioned cylindrical portion 44 is formed in a portion of the independent conductor 42 opposite to the common conductor 41, and is connected to the lower portion of the cylindrical portion 44 and has a head portion of a connection bolt 13 for connecting a branch terminal 45. Are formed, and a through hole 47 through which a bolt shaft portion penetrates is formed, and a contact piece 48 for connecting a branch terminal is mounted at a lower end portion.

The cylindrical portions 43 and 4 of the common conductor and the independent conductor
4 is provided with a contact piece 49 for maintaining good electrical contact with the fuse.

As shown in FIGS. 2A and 2B, the fuse 50 is formed in a cylindrical shape, and connection portions 52 and 53 of a bottomed cylindrical conductor are provided at both ends of a body portion 51 formed of an insulating material. An electrical contact surface 54 is formed on the outer peripheral surface of the cylindrical portion, and is connected to a contact piece 49 mounted on the common conductor 41 and the independent conductor 42.

On the upper end surface of the fuse 50, a knob 55 for detaching operation, a fusing display section 56, a capacity display section 57 and the like are formed.

In this embodiment, when the replacement is performed by blowing the fuse, the waterproof dome 4 is removed, the waterproof cap 20 is removed, and the knob 55 of the fuse 50 whose fuse blowing indicator 56 is discolored is pinched with pliers or the like. All that is required is to extract and insert a new fuse. If the waterproof cap 20 is made of a transparent material, a blown fuse can be found without removing the cap.

[0026]

As described above, according to the present invention, the branch conductor is divided into the common conductor and the independent conductor, and the cylindrical fuse is linearly inserted and removed between them. The overcurrent and short-circuit current from the customer to the customer can be protected by fusing, and a compact low-pressure branching device with excellent maintenance and management can be obtained as an underground type.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a main part of an embodiment of a branch body of the present invention.

FIG. 2 shows an embodiment of the fuse of the present invention.
(A) is a fuse front view, (b) is a top view.

FIG. 3 is a front sectional view showing a configuration of a conventional low-pressure branching device.

FIG. 4 is a side sectional view showing a configuration of a conventional low-pressure branching device.

FIG. 5 is a plan view showing a configuration of a conventional low-pressure branching device.

FIG. 6 shows a detailed structure of a conventional branch body.
(A) is a plan view, (b) is a partial front sectional view, and (c) is a bottom view.

FIG. 7 is a system diagram of an underground low-voltage distribution line using a low-voltage branching device.

[Explanation of symbols]

1 branch body, 2 mounting bracket, 4 waterproof dome, 5 handhole, 11 branch conductor, 12 branch terminal, 13 connection bolt, 14 branch cable, 15 rubber mold,
Reference Signs List 16 fixing bracket, 17 fixing bolt, 18 connection cover, 19 watertight band, 20 waterproof cap, 21 protrusion, 22 connector, 31 transformer, 32 underground distribution cable, 33 low-voltage branching device, 34 branch cable, 41
Common conductor, 42 independent conductor, 43, 44 cylindrical part, 4
5 branch terminal, 46 receiving hole, 47 through hole, 48 contact piece, 49 contact piece, 50 fuse, 51 trunk, 5
2,53 connection part, 54 contact surface, 55 knob, 56
Fusing display, 57 capacity display

Claims (2)

[Claims] 1. A box-shaped handhole is used to connect a branch conductor composed of a branch conductor for relaying and connecting a low-voltage distribution line of underground wiring to a customer and branching and distributing power to a customer and a branch terminal for cable connection connected to the branch conductor. In the stored underground type low-voltage branching device, the connection conductor of the branch terminal is constituted by a common conductor and an independent conductor, and a connection portion where a fuse can be attached and detached is formed on the common conductor and the independent conductor, and the fuse is mounted on the connection portion. And a branch circuit is electrically configured by performing the above operation. 2. A fuse connecting part of a common conductor and an independent conductor is formed in a cylindrical shape, and an elastic conductor which is in contact with the inner surface of the cylindrical body is attached. At the both ends of the fuse, a cylindrical connecting part is formed. 2. The low-pressure branching device with a built-in fuse according to claim 1, wherein the device can be electrically connected and removed by linearly inserting and removing the device.