JP2020127253A - Working ground fixing box - Google Patents

Abstract

To provide a working ground fixing box capable of safely fixing working ground to a power cable.SOLUTION: A working ground fixing box comprises: a conductive ground fixing terminal 16 fixed to a power cable; an upper box body 11 and a lower box body 12, which function as ground fixing terminal storage boxes that can be opened or closed for storing the ground fixing terminal 16 in an insulated state from outside; a ground hook insertion cylinder 14 attached to a side face of the upper box body 11; and a cap 17 removed from the ground hook insertion cylinder 14 while working ground is fixed. A length of the ground hook insertion cylinder 14 is set to secure an approach safety distance. When the working ground is fixed, a ground hook being a grounding instrument of overhead wire is inserted into the upper box body 11 via the ground hook insertion cylinder 14 after the cap 17 is removed from the ground hook insertion cylinder 14, and the ground hook is connected to the ground fixing terminal 16.SELECTED DRAWING: Figure 1

Description

The present invention relates to a work ground mounting box suitable for mounting a work ground on a sealed power cable.

Conventionally, when the outlet is an electric power cable (such as a transmission line) and the substation equipment is a gas composite switchgear, there is no place to install a work ground on the line side, which may pose a danger to the operator during inspection. was there.

In addition, it is necessary to carry out inefficient business operation, such as when the distribution line (high-voltage line) of the sales office is working, the switch gear of the substation has to be equipped with a second earth (working earth) on the power cable at the sales office. It was

As a method for solving such a problem, in Patent Document 1 below, in order to reliably prevent an electric shock accident during construction by allowing a conductor to be directly grounded at a place where construction is performed, a power cable line A branch connector body of a branch connector, which is provided on the way and in which a front and rear two main cables and a branch cable are connected to each other in a state in which a male connector and a female connector are fitted to each other. A conductor grounding adapter capable of connecting a grounding wire is provided between the cable terminal and the conductor grounding adapter, and the conductor grounding adapter is capable of fitting with the connector of the branch connector body and the connector of the cable terminal. It has a second connector at both ends, and a ground wire connection part is provided in the middle of them, and the ground wire connection part is usually covered with a cap, so that the work can be performed at the branch connection part. Discloses a power cable branch connection in which a cap is removed and a ground wire is connected thereto.

JP 2000-299908 A

However, in the power cable branching connection portion disclosed in the above-mentioned Patent Document 1, the worker may get an electric shock if the battery is charged when the cap is removed. There is a problem that it is difficult to use it for work ground attachment work.

Also, in the case of the gas combined switchgear, the cable termination box (cable end) is inside the pressure tank, so it is not possible to attach a working ground to the power cable side of the cable termination box (sealed power cable) There's a problem.

An object of the present invention is to provide a work ground attachment box in which a work ground can be safely attached to a power cable.

A work ground mounting box of the present invention is a work ground mounting box (10, 50) for mounting a work ground on a power cable (20), and a conductive ground mounting terminal ( 16, 55), a ground mounting terminal storage box for storing the ground mounting terminal in an insulated state from the outside, and a ground hook (110 attached to the ground mounting terminal storage box during work ground mounting work. ) Is inserted along the power cable into the earth attachment terminal storage box to connect to the earth attachment terminal, and the earth hook insertion tube (14, 53), and the earth hook insertion during the work earth attachment operation. And a cap (17, 56) detached from the cylinder, wherein the earth hook insertion cylinder has a length capable of ensuring a safe approach distance.
Here, the earth hook insertion cylinder may be attached to a side surface of the earth attachment terminal storage box near a rear surface.
The work earth attachment box (10) includes an upper box body (11) and a lower box body (12) that can be opened and closed by a hinge (13) as the earth attachment terminal storage box. Semicircular cutouts may be provided on the left and right side surfaces and on the left and right side surfaces of the lower box body so as to allow the power cable to pass therethrough and clamp it when closed.
The work earth attachment box (50) includes a box body (51) and a holding lid (52) as the earth attachment terminal storage box, and the box body includes a main body portion (51a) and a cylinder in the main body portion. A holding part (51c) attached via a connecting part (51b), and a front leg part (51d) and a rear leg part (51e) attached to the front end part and the rear end part of the main body part, respectively. A mounting portion (55a) of the earth mounting terminal to the power cable is sandwiched between the sandwiching portion and the sandwiching lid of the box body, and a connecting portion (55b) of the earth mounting terminal to the ground hook. May be housed in the main body of the box body via the holding portion and the connecting portion.

The working earth attachment box of the present invention has the following effects.
(1) Since the cap can be removed from the earth hook insertion cylinder while ensuring a close safety distance, the working earth can be safely attached to the power cable of extra high voltage or higher.
(2) Since the work earth mounting box is attached to the power cable, the work ground can be attached to the sealed power cable.
(3) Detection of electricity during power outage work ・Installation of a work ground mounting box for insulators on gas composite switchgear and distribution line cables that do not have a grounded part in work with grounding ensures a safe approach distance for inspection. Work with electricity and ground can be performed safely.

It is a figure for demonstrating the structure of the work earth mounting box 10 by the 1st Example of this invention, (a)-(d) is a top view, left side view, front view of the work earth mounting box 10. FIG. And (f) are a front view and a right side view of the ground attachment terminal 16. It is a figure for demonstrating the procedure of the work earth attachment box attachment work which attaches the work earth attachment box 10 shown in FIG. 1 to the electric power cable 20, and (a), (b) demonstrates procedure 1,2. And (c) and (d) are top views for explaining steps 3 and 4. It is a figure for demonstrating the procedure of the work earth attachment work using the work earth attachment box 10 shown in FIG. 1, (a)-(c) is a top view for demonstrating the steps 1-3. is there. It is a figure for demonstrating the structure of the work earth mounting box 50 by the 2nd Example of this invention, (a) is a front view of the work earth mounting box 50 which omitted the front leg part 51d, (b) 8A is a right side view of the work ground attachment box 50, and FIGS. 8C and 8D are a front view and a right side view of the ground attachment terminal 55. It is a figure for demonstrating the procedure of the work earth attachment work using the work earth attachment box 50 shown in FIG. 4, (a) is a front view for demonstrating the procedure 1, (b)- (D) is a front view in which the front leg part 51d is omitted for explaining the steps 2 to 4. It is a figure which shows the structure of the earth hook 110.

For the above purpose, attach a ground hook insertion tube with a length that can secure a safe approach distance to the ground mounting terminal storage box, remove the cap from the ground hook insertion tube when installing the work ground, and then insert the ground hook. It was realized by connecting the work ground to the power cable through the ground mounting terminal inside the ground mounting terminal storage box.

Embodiments of a work earth mounting box of the present invention will be described below with reference to the drawings.
In the following description, the power cable 20 (see FIG. 2A) is for 110 kV and has a diameter of about 10 cm.

The working earth attachment box of the present invention has the following features.
(1) The structure is such that a safe approach distance can be secured without the risk of electric shock to the worker when the cap is removed.
(2) The structure is such that the power cable is attached not between the cable terminal and the connection device.
(3) It is equipped with a ground attachment terminal that can use an overhead wire ground as a working ground.

Therefore, a ground hook that is generally used as a grounding device for overhead lines is used for the work ground installation work.
Such an earth hook is, for example, like an earth hook 110 shown in FIG. 6, an insulating operation rod 111, a header 112 attached to the tip of the operation rod 111, and an opening/closing hook 113 attached to the header 112. And an earth lead 114 whose one end is electrically connected to the opening/closing hook 113.
The opening/closing hook 113 is opened/closed by rotating the operating rod 111 around the axis, as indicated by an arrow in the figure.
The width d (the length from the tip of the opening/closing hook 113 to the outer end surface of the earth lead wire 114) of the ground hook 110 when the opening/closing hook 113 is fully opened is about 15 cm.

As shown in FIGS. 1(a) to 1(d), the working earth mounting box 10 according to the first embodiment of the present invention has a rectangular box-shaped upper box body 11 whose lower surface is an open surface and an upper surface having an upper surface. A rectangular box-shaped lower box body 12 having an opening surface, a hinge 13, a rectangular tube-shaped ground hook insertion tube 14, a disc-shaped confirmation window 15, a conductive ground attachment terminal 16, and a cap 17 And.

The upper box 11 and the lower box 12 have a function as an openable/closable ground mounting terminal storage box for storing the ground mounting terminal 16 in an insulated state from the outside, and a function of holding the power cable 20 by sandwiching it from above and below. Is to have.

Therefore, the upper box 11 and the lower box 12 are made of an insulator (such as wood), and the hinges 13 are attached to the center of the lower end of the surface of the upper box 11 and the center of the upper end of the surface of the lower box 12. In addition, the lower and upper surfaces of the upper box 11 and the lower surface of the lower box 12 for closing the upper and lower boxes 11 and 12 by bolting are closed. A flange having a plurality of bolt holes (not shown) is provided at the upper ends of the back surface and the right side surface.

In addition, as shown in FIGS. 1B and 1D, the upper box 11 and the lower box are provided at the center of the lower ends of the left and right sides of the upper box 11 and in the center of the upper ends of the left and right sides of the lower box 12. When the cable 12 is closed, a power cable through hole A is formed so as to allow the power cable 20 to penetrate therethrough, and a semi-circular cutout for holding the power cable 20 is provided.

In order to more securely insulate the ground mounting terminal 16 housed in the ground mounting terminal storage box from the outside, the contact portion between the upper box 11 and the lower box 12 (the flange of the upper box 11 is A packing-like insulator (rubber packing or the like) is attached to a contact portion (a semi-circular cutout) between the lower surface and the upper surface of the flange of the lower housing 12) and the power cable 20 of the upper housing 11 and the lower housing 12. May be.

The ground hook insertion cylinder 14 is for inserting the ground hook 110 into the upper box 11 along the power cable 20 at the time of work ground attachment work, and is vertical to the right side surface of the upper box 11. Thus, the left end is attached to the right side surface of the upper box 11.
The ground hook insertion cylinder 14 has a horizontally long rectangular shape with an opening surface of about 10 cm in length and about 20 cm in width, and has a length (axial length) of about 180 cm to secure a safe approach distance. ..
The ground hook insertion tube 14 is moved toward the rear side above the right side surface of the upper box body 11 (shifted from the vertical center line of the right side surface of the upper box body 11 as shown in FIG. And diagonally to the right).

The confirmation window 15 is for confirming that the ground hook 110 is securely attached to the ground attachment terminal 16, is made of a transparent insulating material (such as glass), and has an upper box. It is attached to the center of the upper surface of the body 11.

The ground attachment terminal 16 is made of a conductive metal such as aluminum and is T-shaped in a front view. As shown in FIGS. 1(e) and 1(f), the lower surface center portion is cut along the axial direction. The compressed portion 16a has a half-split pipe shape, and the mounting portion 16b has a round bar shape that is erected at the center of the upper surface of the compressed portion 16a.
The ground attachment terminal 16 is obtained by inserting the core wire 20a (see FIG. 2A) of the power cable 20 from below into the compression portion 16a with the compression portion 16a opened as shown by the dotted line in FIG. 1(f). The power cable 20 is attached by closing the compression unit 16a using a hydraulic compression tool or the like.

The cap 17 is made of an insulating material (rubber or the like), is normally attached to the right end surface of the ground hook insertion cylinder 14, and is removed from the ground hook insertion cylinder 14 during the work earth attachment work.

Next, the procedure of the work earth attachment box attachment work for attaching the work earth attachment box 10 to the power cable 20 will be described with reference to FIGS.
In addition, the work ground mounting box installation work will be performed during a power outage.

(Procedure 1) The operator removes the coating 20b of the power cable 20 to expose the core wire 20a, inserts the exposed core wire 20a into the compression portion 16a of the ground attachment terminal 16 from below, and then the hydraulic compression tool or the like. The compression portion 16a is closed by using, and the ground attachment terminal 16 is attached to the power cable 20 (see FIG. 2A).

(Procedure 2) The worker performs the insulation treatment of the power cable 20 using the insulation treatment member 30 by coating an insulation material or winding an insulation tape (the insulation treatment member 30 is shown in a cross section). See FIG. 2B).

(Procedure 3) The worker covers the upper box 11 on the power cable 20 from above with the lower box 12 of the work ground attachment box 10 opened and the cap 17 attached to the ground hook insertion tube 14.
At this time, the operator looks into the upper box 12 through the confirmation window 15 so that the ground attachment terminal 16 is located at the center of the upper box 12 (see FIG. 2C).

(Procedure 4) The worker penetrates the power cable 20 through the power cable through hole A of the work ground attachment box 10 to close the lower box 12, and then the upper box 11 and the upper box 11 are secured so as to ensure the internal insulation. The lower box body 12 is bolted to attach the work ground attachment box 10 to the power cable 20 (see FIG. 2D).

As a result, the work earth attachment box 10 can be always attached to the power cable 20, so that the work earth attachment box 10 can be used to perform work earth attachment work when inspecting the gas composite switchgear or the like.

Next, the procedure of the work earth attachment work at the time of inspecting the gas combined switchgear will be described with reference to FIGS.
(Procedure 1) An operator removes the cap 17 from the ground hook insertion cylinder 14 (see FIG. 3A).
At this time, even if the power cable 20 is in the charged state, the worker can remove the cap 17 while ensuring the approach safety distance by the ground hook insertion tube 14.

(Procedure 2) The operator opens the opening/closing hook 113 and inserts the ground hook 110 into the ground hook insertion tube 14 with the ground attachment terminal 16 side (see FIG. 3B).

(Procedure 3) The operator operates the operating rod 111 of the ground hook 110 to hook the opening/closing hook 113 on the mounting portion 16b of the ground mounting terminal 16, and then closes the opening/closing hook 113 to clamp the mounting portion 16b ( See FIG. 3C).
At this time, the operator looks into the upper box 12 through the confirmation window 15 and confirms that the ground hook 110 is securely attached to the ground attachment terminal 16.

Thereby, the worker electrically connects the ground lead wire 114 of the ground hook 110 and the core wire 20a of the power cable 20 via the ground mounting terminal 16 to safely attach the working ground to the power cable 20. be able to.

When the inspection of the gas combined switchgear is completed, the operator operates the operating rod 111 of the ground hook 110 to open the open/close hook 113, removes the open/close hook 113 from the mounting portion 16b of the ground mounting terminal 16, and then grounds it. The hook 110 is pulled out from the ground hook insertion tube 14.
After that, the worker puts the cap 17 on the ground hook insertion cylinder 14.

After that, the worker can perform the work earth attachment work in the same procedure when inspecting the gas combined switchgear.

Next, a work ground mounting box 50 according to a second embodiment of the present invention will be described with reference to FIGS.
As shown in FIGS. 4A and 4B, the working earth attachment box 50 according to the present embodiment includes a box body 51, a plate-like holding lid 52, an earth hook insertion cylinder 53, and a confirmation window 54. , A ground attachment terminal 55 and a cap 56.

Here, the ground hook insertion cylinder 53, the confirmation window 54, the ground attachment terminal 55, and the cap 56 are the same as the ground hook insertion cylinder 14, the confirmation window 15, the ground attachment terminal 16, and the cap 17 of the work ground attachment box 10 described above. Since it has the above configuration, the description thereof will be omitted.

The box body 51 and the sandwiching lid 52 have a function as a ground mounting terminal storage box for storing the ground mounting terminal 55 in an insulated state from the outside, and are made of an insulating material (such as wood).

The box body 51 has a rectangular box-shaped main body portion 51a, a cylindrical connecting portion 51b whose upper end surface is attached to the central portion of the lower surface of the main body portion 51a, and an upper central portion which is attached to the lower end surface of the connecting portion 51b. Plate-shaped holding portion 51c, a rectangular thin plate-shaped front leg portion 51d (see FIG. 4B) whose upper end surface is attached to the front end portion of the lower surface of the main body portion 51a, and the upper end surface is the lower surface of the main body portion 51a. A rectangular thin plate-shaped rear leg portion 51e (having the same size as the front leg portion 51d) attached to the rear end portion.

At the central portion of the lower surface of the main body portion 51a of the box body 51 and the central portion of the upper surface of the sandwiching portion 51c, a mounting portion 55b of the ground mounting terminal 55 is provided via a connecting portion 51b (see FIGS. 4C and 4D) A through hole is formed for passing through.
Further, a semicircular groove for holding the compressed portion 55 a of the ground attachment terminal 55 is formed on the lower surface of the holding portion 51 c of the box body 51 and the upper surface of the holding lid 52.

The ground hook insertion tube 53 is for inserting the ground hook 110 into the main body portion 51a of the work ground attachment box 50 with the opening/closing hook 113 on the ground attachment terminal 55 side, similarly to the ground hook insertion tube 14 described above. In order to reduce the lateral dimension, the main body portion 51a is attached to the right side surface of the main body portion 51a at a position diagonally to the upper right, offset from the vertical center line (see FIG. 4B).

Next, the procedure of the work earth attachment box attachment work for attaching the work earth attachment box 50 to the power cable 20 will be described with reference to FIGS.
In addition, the work ground mounting box installation work will be performed during a power outage.

(Procedure 1) The operator removes the coating 20b of the power cable 20 to expose the core wire 20a, inserts the exposed core wire 20a into the compression portion 55a of the ground attachment terminal 55 from below, and then the hydraulic compression tool or the like. The compression portion 55a is closed by using, and the ground attachment terminal 55 is attached to the power cable 20 (see FIG. 5A).

(Procedure 2) The worker attaches the box body 51 to the power cable 20 until the crimp portion 55a of the earth attachment terminal 55 contacts the holding portion 51c of the box body 51 with the cap 56 attached to the earth hook insertion tube 53. Cover from above (see FIG. 5(b)).
At this time, the operator inserts the mounting portion 55b of the ground mounting terminal 55 into the main body portion 51a through the through hole of the holding portion 51c of the box body 51, the connecting portion 51b and the through hole of the main body portion 51a. This operation is performed while looking into the main body 51a through the confirmation window 54.

(Procedure 3) The operator inserts the sandwiching lid 52 from below the box body 51 to bring the sandwiching lid 52 into contact with the sandwiching portion 51c of the box body 51, and then joins the both (see FIG. 5C).
As a joining method at this time, an adhesive or an insulating tape may be used.

(Procedure 4) The worker performs the insulation treatment of the power cable 20 using the insulation treatment member 60 by coating the insulation material or winding the insulation tape (see FIG. 5D).

As a result, the work earth attachment box 50 can be always attached to the power cable 20, so that the work earth attachment box 50 can be used to perform work earth attachment work when the gas composite switchgear is inspected.
Since the procedure at this time is the same as the procedure for the work earth attachment work using the work earth attachment box 10 described above (see FIGS. 3A to 3C), the description thereof will be omitted.

Further, since the work earth attachment box 50 includes the front leg portions 51d and the rear leg portions 51e, the work earth attachment box 50 can be kept standing on the ground or the like.

In the above description, the work ground attachment boxes 10 and 50 are attached without cutting the power cable 20, but when the power cable 20 is cut, the core wire 20a of the cut power cable 20 is connected to the ground attachment terminal 16. , 55 may be connected by the compression parts 16a, 55a, and then the work earth attachment boxes 10, 50 may be attached.
In this case, the compression portions 16a and 55a of the ground attachment terminals 16 and 55 may be cylindrical because the core wires 20a of the power cable 20 can be inserted from the left and right end surfaces.

Also, for power cables that have a built-in sheath ground to prevent electric shock from being charged, the sheath ground is disconnected when the sheath of the power cable is removed.Therefore, perform insulation treatment after connecting the disconnected sheath ground. Try to do it.

10,50 Ground mounting box for work 11 Upper box 12 Lower box 13 Hinges 14,53 Ground hook insertion tube 15,54 Confirmation window 16,55 Ground mounting terminal 16a Compressed section 16b Mounting section 17,56 Cap 20 Power cable 20a Core wire 20b Covering 30, 60 Insulation processing member 51 Box 51a Main body 51b Connecting part 51c Clamping part 51d Front leg part 51e Rear leg part 52 Clamping lid 110 Ground hook 111 Operation rod 112 Header 113 Opening hook 114 Ground lead wire A Power cable Through hole d width

Claims (4)

A work earth attachment box (10, 50) for attaching a work earth to an electric power cable (20),
A conductive ground attachment terminal (16, 55) attached to the power cable;
A ground mounting terminal storage box for storing the ground mounting terminal in an insulated state from the outside,
To connect to the earth mounting terminal by being attached to the earth mounting terminal storage box and inserting the earth hook (110) into the earth mounting terminal storage box along the power cable at the time of working earth mounting work. Earth hook insertion tube (14, 53) of
A cap (17, 56) that is removed from the earth hook insertion cylinder during the work earth attachment work,
The earth hook insertion tube is of a length that can ensure a safe approach distance,
This is a work ground mounting box. The work earth attachment box according to claim 1, wherein the earth hook insertion cylinder is attached to a side surface of the earth attachment terminal storage box near a rear surface. The work ground mounting box (10) is
The earth mounting terminal storage box includes an upper box body (11) and a lower box body (12) that can be opened and closed by a hinge (13),
Semi-circular cutouts are provided on the left and right side surfaces of the upper box body and on the left and right side surfaces of the lower box body for allowing the power cable to pass therethrough and holding it when closed,
The work earth mounting box according to claim 1 or 2, characterized in that. The work ground mounting box (50) is
As the earth-attached terminal storage box, a box body (51) and a holding lid (52) are provided,
The box is
A main body (51a),
A sandwiching part (51c) attached to the main body part through a tubular connecting part (51b);
A front leg portion (51d) and a rear leg portion (51e) attached to the front end portion and the rear end portion of the main body, respectively,
A mounting portion (55a) of the earth mounting terminal to the power cable is sandwiched between the sandwiching portion and the sandwiching lid of the box body, and a connecting portion (55b) of the earth mounting terminal to the ground hook is formed. Stored in the main body of the box via the sandwiching portion and the connecting portion,
The work earth mounting box according to claim 1 or 2, characterized in that.

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