KR102549097B1 - Uninterruptible power distribution work method for low voltage line - Google Patents

Abstract

The present invention relates to an uninterruptible power distribution construction method for low-voltage lines, comprising: a first step of installing a branching device and a phase detection and blocking device at a predetermined location in order to perform uninterruptible power distribution construction for low-voltage lines; A second step of connecting a lead wire between a transformer of a mobile transformer train and a branching device connected to the transformer, and connecting a low voltage cable between the branching device and a phase detection and cutoff device; When the connection of the lead wire and the low voltage cable are completed, a third step of inputting a circuit breaker of the detection circuit breaker after the detection is performed; A fourth step of separating the pole-side transformer and the low voltage wire when the circuit breaker of the phase detection and blocking device is input, and carrying out the main work of uninterruptible power distribution construction for the low voltage line including transformer replacement and wire replacement; and a fifth step of reconnecting the pole-side transformer and the low-voltage wire and opening a circuit breaker of the phase detection circuit breaker when the main work is completed.

Description

Low voltage line uninterrupted power distribution construction method {UNINTERRUPTIBLE POWER DISTRIBUTION WORK METHOD FOR LOW VOLTAGE LINE}

The present invention relates to an uninterruptible power distribution construction method for low voltage lines, and more particularly, to a low voltage uninterruptible power distribution construction method for performing uninterruptible power distribution construction for low voltage lines more efficiently and safely.

Recently, as the level of public demand for electricity quality has increased, uninterruptible power distribution construction is mainly being carried out for power supply without interruption during distribution line maintenance and repair work, such as relocation of designated poles or renovation work.

Here, as one of the uninterruptible power distribution construction, there is a special high voltage bypass cable construction method in which a bypass line is constructed using a special high voltage bypass cable and a construction switch in the work section, and the work section is put into a power outage state to carry out construction. There is a wire transfer method in which bypass lines are constructed using extra-high voltage overhead wires rather than cables, and electric poles or wires are relocated while the working section is live.

However, since the wire transfer method requires the work to be performed while the working section is live, it is difficult to secure the safety of workers such as the possibility of an electric shock accident. Currently, uninterruptible power distribution construction is being carried out mainly with the special high voltage bypass cable method. .

For the uninterruptible power distribution work of the low-voltage line among the above-mentioned special high-voltage bypass cable construction methods (e.g., terminal substation or branch line uninterruptible construction, etc.), as shown in FIG. 1, the construction switch (G ), extra-high voltage bypass cable car, and moving transformer train, etc. were configured as devices for uninterruptible power distribution construction on one low-voltage line, and distribution construction was carried out.

Referring to FIG. 1, the existing low-voltage line uninterruptible power distribution construction work procedure configures a special high-voltage bypass line using a bypass cable and a cable junction box, applies power to a construction switch, performs live-line jumper separation, and transformer The installation pole utilizes a mobile transformer train to supply low-voltage power and implements the construction by making the work section oblique. In FIG. 1, the low-voltage riser cable is a cable that connects a trunk cable (or trunk cable) to a low-voltage line for uninterruptible work. The trunk cable (or trunk cable) is a cable installed to supply power to overhead low-voltage lines subject to uninterruptible supply.

However, for the uninterruptible power distribution work using the conventional low-voltage line uninterruptible power distribution work device, it is necessary to construct a bypass line from the electric pole to the mobile transformer train using the special high voltage bypass cable, and there are many components, so the work place for the power distribution work is difficult. There were difficulties in power distribution work in narrow or high-traffic areas. In addition, due to the characteristics of the special high voltage bypass cable used at this time, there is a high possibility of secondary accidents (e.g., electric shock accidents, power outages).

Therefore, there is a need for a method to more efficiently and safely perform uninterruptible power distribution work for low voltage lines.

The background art of the present invention is disclosed in Republic of Korea Patent Registration No. 10-0138717 (registered on February 20, 1998, bypass live wire work method using an insulated cable).

According to one aspect of the present invention, the present invention was created to solve the above problems, and provides an uninterruptible power distribution construction method for low voltage lines, which enables more efficient and safe performance of uninterruptible power distribution construction for low voltage lines. It has a purpose.

A low-voltage line uninterruptible power distribution construction method according to an aspect of the present invention includes a first step of installing a branching device and a phase detection blocker at a pre-specified location in order to perform low-voltage line uninterruptible power distribution construction; A second step of connecting a lead wire between a transformer of a mobile transformer train and a branching device connected to the transformer, and connecting a low voltage cable between the branching device and a phase detection and cutoff device; When the connection of the lead wire and the low voltage cable are completed, a third step of inputting a circuit breaker of the detection circuit breaker after the detection is performed; A fourth step of separating the pole-side transformer and the low voltage wire when the circuit breaker of the phase detection and blocking device is input, and carrying out the main work of uninterruptible power distribution construction for the low voltage line including transformer replacement and wire replacement; and a fifth step of reconnecting the pole-side transformer and the low-voltage wire and opening the circuit breaker of the phase detection circuit breaker when the main work is completed.

In the present invention, the low-voltage cable is connected through a movable cable drum device, and the movable cable drum device is moved in a state of being placed on a cart that fixes both sides of the axis of the main body of the drum device for winding or unwinding the low-voltage cable. It includes a cart that is fixed or fixed, and wheels for movement are mounted on the lower part of the cart, and the area for winding the low-voltage cable is divided into two areas so that both ends of the cable start point and end point can be utilized in a state in which only part of the low-voltage cable is unwound. A separation membrane is formed, and a handle capable of rotating the drum device body is formed on one side of the drum device body in order to unwind or rewind the low voltage cable.

In the present invention, the branching device is a portable low-voltage cable branching device that can be connected to two terminals for each phase of a mobile transformer train, is formed in a form housed in a case with a portable handle, has a ground terminal, and one-touch connection. It is formed in a form that makes it easy to connect and separate the low-voltage cable using this possible connection material, and is formed in three circuits so that the low-voltage cable can be branched from the branch line. It is formed to enable connection separation in a one-touch method, and is characterized in that it has a function to prevent loosening due to twisting of the low-voltage cable.

In the present invention, the phase detection cutoff device is a portable low voltage cutoff device having a circuit breaker and a low voltage detection function to supply or cut off low voltage power after rectifying a phase in case of phase mismatch, and includes a handle for carrying. It is formed to be accommodated in the housing provided, and the detection function allows to check whether there is a phase mismatch when voltage is applied to the power side and the attached cable in the circuit breaker open state. For this purpose, the detector related information is displayed on the detector display panel outside the enclosure As a, the phase detection display, phase loss display, live wire display, and phase selection display are displayed using lamps, and when coupled with the connection terminal of the low voltage cable, it is formed to be disconnected with one turn, and to prevent loosening due to twisting of the low voltage cable It is characterized by having a function.

According to one aspect of the present invention, it is possible to more efficiently and safely perform uninterruptible power distribution work for low voltage lines.

1 is an exemplary diagram shown for explanation of a conventional special high voltage bypass cable method;
Figure 2 is an exemplary view showing the components required for the implementation of the low-voltage line uninterruptible power distribution construction method according to the present invention in pictures.
Figure 3 is an exemplary view showing a flow chart for explaining a low-voltage line uninterruptible power distribution construction method according to an embodiment of the present invention.
Figure 4 is an exemplary view shown to compare the difference between the low voltage line uninterruptible power distribution construction method and the conventional uninterruptible power distribution construction method according to an embodiment of the present invention.

Hereinafter, an embodiment of an uninterruptible power distribution construction method for low voltage lines according to the present invention will be described with reference to the accompanying drawings.

In this process, the thickness of lines or the size of components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of a user or operator. Therefore, definitions of these terms will have to be made based on the content throughout this specification.

Figure 2 is an exemplary diagram showing the components necessary for the implementation of the low-voltage line uninterruptible power distribution construction method according to the present invention in pictures, as shown in (A), a movable low-voltage cable drum device (hereinafter simply described as a movable cable drum device) As shown in (100) and (B), a portable low-voltage cable branching device capable of connecting to two terminals of a mobile transformer train (hereinafter, simply referred to as a branching device) (200) and (C) A portable low-voltage circuit breaker with a phase detection function (hereinafter, it can be simply described as a phase detection circuit breaker or a circuit breaker) 300, and a transformer-connection box (or low-voltage cable branching device) as shown in (D), and a junction box ( or a lead wire (hereinafter, simply referred to as a lead wire) 400 capable of being connected between a low-voltage cable branching device and a low-voltage riser in a one-touch manner.

The movable low-voltage cable drum device 100 winds, moves and stores low-voltage cables, and performs a function of installing and removing construction cables during work.

For reference, since the conventional cable drum device is of a fixed type, it is difficult to move, and there is a problem in that the entire cable wound around the drum device must be unwound in order to utilize the cable.

However, the movable low-voltage cable drum device (A) according to the present embodiment is easily movable in the field, can be connected to power by unwinding only a required length, and is easy to rewind.

As shown in (a) to (c) of FIG. 2 (A), the movable low-voltage cable drum device 100 is a frame (or cart) that fixes both sides of the axis of the drum device body (cable winding device). ) is equipped with small wheels on the lower part of the drum device so that it can be moved even when the drum device is raised and fixed, and the cable can be unwound or wound by rotating the drum device in a stopped state.

)을 형성하고, 공사완료 후 저압 케이블의 재 권취가 용이하도록 핸들(

)을 형성한다. 설명이 생략된 영역(

)은 케이블 권취 시 시작점(또는 끝점)을 권취할 수 있도록 미리 구분된 영역을 의미한다.In addition, as shown in (d) of FIG. 2 (A), when winding the cable, the start point and the end point are separated and formed in a form that can be wound, and the cable separator can be used without unwinding the entire cable (

) is formed, and the handle (

) to form Areas omitted from description (

) means a pre-divided area so that the start point (or end point) can be wound when winding the cable.

The portable low-voltage cable branching device 200, which can be connected to two terminals (eg, low-voltage distribution box terminals) for each phase of the mobile transformer train, is a main cable (ie, uninterruptible supply target processing) in the low-voltage distribution box (not shown) of the mobile transformer train. A cable installed to supply power to a low-voltage line), between trunk cables, or as a connection device and branching device that supplies low-voltage power to branch cables in trunk cables.

For reference, the conventional cable branching device (not shown) connects the cable to the booth connecting device (not shown) made of copper (e.g., compressing the cable to the connection terminal, then attaching it to the connection groove and tightening it with a hexagon wrench) However, since it is a device mainly used for underground lines and is formed in a form without a cover device and exposed to the ground, there is a problem in utilization. Currently, the supply capacity of the mobile transformer train is 300kVA, and the secondary side terminals are composed of two for each phase (2 R terminals / 2 S terminals / 2 T terminals / 2 N terminals).

Accordingly, as shown in (a) and (b) of FIG. It is stored in and formed so that it can be moved safely without being exposed to the outside, and is formed to eliminate restrictions in the installation place by providing a ground terminal (not shown) to increase safety, and cable connection is connected using a connecting material that allows one-touch connection. and is formed in an easy-to-separate form.

Referring to (a) and (b) of FIG. 2 (B), the portable low-voltage cable branching device 200 connectable to the two terminals of the mobile transformer train is in the low-voltage distribution box (not shown) of the mobile transformer train. It can connect 2 lines of withdrawable cable, and it is formed with 3 circuits to enable branching of low-voltage cables in branch lines. In addition, the contact point is formed in the form of a booth made of copper, and the cable lead-in and out portion forms a contact point so that the lead wire is connected in a one-touch method by rotating the lead wire in a spiral form, and is provided with a function to prevent loosening due to cable twisting, and at least 70 to 185 It is formed in a size that allows the use of a ㎟ standard cable. In addition, a handle (not shown) is formed in the enclosure to improve safety by providing a ground terminal and to facilitate portability and movement.

The portable low-voltage circuit breaker 300 having the checking function performs a function of connecting and disconnecting low-voltage lines to secure worker safety and line safety by branching from a trunk cable and matching phases between lines when supplying low-voltage power. In addition, the portable low voltage circuit breaker 300 having the detection function includes a detection unit (not shown) capable of measuring phases (ie, three phases) when branched off from a main line and connected to a low voltage line, and is made of stainless steel. It is stored in a box and is formed in a form that is easy to move and install.

For reference, the conventional low-voltage circuit breaker does not include an inspection function, and is utilized in a form attached to a low-voltage distribution box (ie, in a non-movable form).

However, in the portable low voltage circuit breaker 300 having the detection function according to the present embodiment, the low voltage circuit breaker is equipped with a power supply-load detection function to correct the phase mismatch and then supply or cut off the low voltage power supply. It is a blocking device with a function.

More specifically, in the portable low voltage circuit breaker 300 having the detection function, the low voltage blocking function (MCCB function) is an integral assembly of a switch and a trip device in an insulator container, and manually or electrically operates the circuit in an energized state. It can be opened and closed by, and it is a function to automatically cut off the current in abnormal conditions such as overload and short circuit. is a function for Alternatively, the inspection function checks in advance whether the phases of the power side (transformer for transport) and the load side (low voltage line side for uninterruptible work) are consistent to prevent systemic accidents that may occur due to phase difference. It is a function to prevent. The inspection function is operated by a power battery (not shown) built into the enclosure.

In addition, as shown in (a) of FIG. 2 (C), the cable inlet and outlet and the enclosure form include a handle (not shown) for easy portability and installation, and are composed of two circuits between power and load.

In addition, as shown in (b) of FIG. 2 (C), outside the box, information related to the detector (eg, phase detection display, phase loss display, live line display, phase selection display, etc.) is converted into visual information (eg, LED lamp) It is implemented so that it can be displayed. That is, in the detection function, when voltage is applied to the power load-side cable in an open state of the circuit breaker, a lamp capable of confirming phase mismatch is displayed on the detector display panel.

Here, the inspection display is display information indicating an inspection state, and a lamp of an image to be inspected is turned on. In the case of image loss display due to incomplete connection during image inspection, the lamp of the image that is image loss is turned on. The live line display is display information indicating whether each phase (R, S, T) of the moving transformer train and each phase (u, v, w) on the low-voltage line side is in a live-line state, and only the phases in the live-line state are turned on.

At this time, when inspection is performed, raise the power switch at the bottom right of the display panel to connect the operating power. 'Phase Selection', 'Phase Inspection Display', 'Phase Loss Display', 'Live Line Display' are all turned on, and the alarm sound continues to sound due to phase loss.

The transformer (moving transformer)-connection box (or low-voltage cable branching device) and connection box (or low-voltage cable branching device)-lead wire 400 that can be connected in a one-touch manner between the low-voltage standing column is shown in FIG. 2 (D). As shown in (a) and (b), the starting point of the lead wire between the transformer (mobile transformer) and junction box (or low-voltage cable branching device) is a rotary terminal so that it can be connected to the low-voltage distribution box (not shown) of the mobile transformer. It is formed including, and the end point is formed including a connection terminal capable of being connected to a cable connection device. In addition, the starting point of the lead wire between the junction box (or low-voltage cable branching device) and the low-voltage riser is formed by including a rotary terminal that can be connected to the cable connecting device, and includes a wire hanging type connection terminal that can connect the end point to the overhead wire. is formed by

At this time, the connection terminal that can be connected to the cable connection device is formed in a one-touch shape that can configure a contact point by one rotation of the cable so that connection and separation are easy, and includes a function to prevent loosening due to a twisting load of the cable.

In addition, the lead wire between the transformer (mobile transformer) and junction box (or low-voltage cable branching device) is at least 8 strands so that the number of low-voltage trunk lines can be varied (eg, 1 to 2 lines) in the portable transformer according to the capacity of the load and installed. A lead wire is provided, and the lead wire is tapped with a specific color (eg, red, blue, white, green, etc.) designated at the start and end points for phase division.

In the above, a method of performing uninterruptible power distribution construction of a low voltage line using the components A, B, C, and D will be described.

3 is an exemplary diagram showing a flow chart for explaining a low-voltage line uninterruptible power distribution construction method according to an embodiment of the present invention.

As shown in FIG. 3, in order to carry out the uninterruptible power distribution work for the low voltage line, the above-described branching device 200 and blocking device 300 (or phase detection and blocking device) are installed at a predetermined location (S101).

In addition, the lead wire between the transformer of the mobile transformer train (i.e., mobile transformer) and the device connected to this transformer (i.e., branching device) and the cables (i.e., low-voltage cable) between each device (e.g., branching device, phase-control device, etc.) Install (connect) (S102).

When the connection of the lead wire and the cable (ie, the low voltage cable) is completed as described above, the circuit breaker (ie, the detection blocking device) 300 is put in after inspection (S103).

As described above, when the circuit breaker (i.e., phase detection blocking device) 300 is input, the main transformer (not shown) and the low voltage wire (not shown) are separated (S104), and the main work (eg, transformer replacement and wire replacement, etc.) ) is carried out (S105).

Accordingly, when the main work is completed, the pole-side transformer (not shown) and the low voltage wire (not shown) are reconnected (S106), and the circuit breaker (ie, phase detection circuit breaker) 300 is opened (S107).

As described above, the low voltage line uninterruptible power distribution construction method according to the present embodiment can simplify the existing complex work process of inputting a large number of equipment, thereby improving work efficiency and improving worker safety, and management accordingly. Economical effects that can reduce costs can be obtained.

4 is an exemplary diagram shown to compare the difference between the low-voltage line uninterruptible power distribution construction method according to an embodiment of the present invention and the conventional uninterruptible power distribution construction method.

Figure 4 (A) is an exemplary view shown in order to compare the conventional method (a) and the method (b) according to the present embodiment of the uninterruptible work of the terminal substation (ie, the telephone pole where the transformer is installed), shown here As described above, the conventional construction method (a) performs construction using a construction switch (G), a special high voltage bypass cable car (SC), and an uninterruptible transformer train (UC) (or a mobile transformer train). Therefore, a work process for connecting the above devices (eg, construction switchgear (G), extra-high voltage bypass cable car (SC), and uninterruptible transformer train (UC)) must be performed.

However, the construction method (b) according to this embodiment performs construction using an uninterruptible transformer train (UC) (or a mobile transformer train) and a low voltage cable drum device (A) (not shown) connected thereto. Accordingly, the work process can be simplified as much as the reduced devices (eg, construction switchgear (G), extra-high voltage bypass cable car (SC), etc.).

Figure 4 (B) is an exemplary view shown to compare the conventional method (a) and the method (b) according to the present embodiment of the uninterruptible construction for three single-phase transformers, as shown therein, the conventional method ( a) uses a construction switch (G), extra-high voltage bypass cable car (SC), three uninterruptible transformer trains (UC) (or mobile transformer trains), and two branch devices (or branch connection devices) (DU). carry out construction Therefore, the work process for connecting the above devices (e.g. construction switch (G), special high voltage bypass cable car (SC), uninterruptible transformer train (UC) x 3 units, branch unit (DU) x 3 units) is carried out. Should be.

However, the construction method (b) according to this embodiment performs construction using an uninterruptible transformer train (UC) (or a mobile transformer train) and a low voltage cable drum device (A) (not shown) connected thereto. Accordingly, the work process can be simplified as much as the reduced devices (e.g., construction switchgear (G), extra-high voltage bypass cable car (SC), uninterruptible transformer train (UC) x 2 units, branch unit (DU) x 3 units, etc.) be able to

Figure 4 (C) is an exemplary diagram shown to compare the conventional method (a) and the method (b) according to this embodiment of the uninterruptible construction for the branch line with a total capacity of less than 300 kVA. Construction method (a) is a construction switch (G), extra-high voltage bypass cable car (SC), two uninterruptible transformer trains (UC) (or mobile transformer trains), and one branching device (or branching connection device) (DU) Carry out the work using Therefore, the work process for connecting the above devices (e.g. construction switchgear (G), extra-high voltage bypass cable car (SC), uninterruptible transformer train (UC) × 2 units, branch unit (DU) × 1 unit) is carried out Should be.

However, the construction method (b) according to this embodiment performs construction using an uninterruptible transformer train (UC) (or a mobile transformer train) and a low voltage cable drum device (A) (not shown) connected thereto. Accordingly, the work process can be simplified as much as the reduced devices (eg construction switchgear (G), extra-high voltage bypass cable car (SC), uninterruptible transformer train (UC) x 1 unit, branch unit (DU) x 1 unit, etc.) be able to

Figure 4 (D) is an exemplary view shown to compare the conventional method (a) and the method (b) according to the present embodiment for uninterruptible work using an existing transformer (if there is room for supply capacity). As shown, in the conventional method (a), construction is performed using one uninterruptible transformer train (UC) (or a mobile transformer train). Therefore, management costs and personnel for using the above device (Uninterruptible Transformer (UC) x 1 unit) must be input.

However, since the construction method (b) according to the present embodiment can be performed using a low-voltage cable drum device (A) (not shown), the work process can be simplified and management costs can be reduced.

As described above, this embodiment includes components developed for the implementation of the uninterruptible power distribution construction method for low-voltage lines (e.g., mobile cable drum device 100, portable low-voltage cable branch device 200, phase detection cutoff device 300, lead wire (400)), it is possible to more efficiently and safely perform uninterruptible power distribution work for low voltage lines.

The present invention has been described above with reference to the embodiments shown in the drawings, but this is only exemplary, and those skilled in the art can make various modifications and equivalent other embodiments. you will understand the point. Therefore, the technical protection scope of the present invention should be determined by the claims below.

100: cable drum device for movement
200: Portable low-voltage cable branching device
300: phase detection blocking device
400: lead wire

Claims (4)

A first step of installing a branching device and a phase detection blocking device at a pre-specified location in order to perform uninterruptible power distribution work on low-voltage lines;
A second step of connecting a lead wire between a transformer of a mobile transformer train and a branching device connected to the transformer, and connecting a low voltage cable between the branching device and a phase detection and cutoff device;
When the connection of the lead wire and the low voltage cable are completed, a third step of inputting a circuit breaker of the detection circuit breaker after the detection is performed;
A fourth step of separating the pole-side transformer and the low voltage wire when the circuit breaker of the phase detection and blocking device is input, and carrying out the main work of uninterruptible power distribution construction for the low voltage line including transformer replacement and wire replacement; and
When the main work is completed, a fifth step of reconnecting the pole-side transformer and the low voltage wire and opening the circuit breaker of the phase detection cutoff device; including,
The inspection blocking device,
A portable low-voltage circuit breaker equipped with a circuit breaker and low-voltage detection function to supply or cut off low-voltage power after correcting the phase in case of phase mismatch,
The detection function allows to check whether there is a phase mismatch when voltage is applied to the power supply side and the attached cable in the open state of the circuit breaker. And the phase selection display is displayed using a lamp,
The image inspection display is display information indicating an image inspection state, and a lamp of the phase to be inspected is turned on, and in the case of the image loss display, when a phase is lost due to an incomplete connection during image inspection, a lamp of the phase to be image loss is turned on, and the live line display is As display information indicating whether each phase (R, S, T) of the mobile transformer train and each phase (u, v, w) on the low-voltage line side is in a live-line state, lamps are turned on only for phases in a live-line state,
When inspection is performed, the operating power is connected by raising the power switch at the bottom right of the display panel. Low-voltage line uninterruptible power distribution construction method, characterized in that all lamps are turned on in 'phase selection', 'phase inspection display', 'phase loss display', and 'live line display' and an alarm sound continues to sound due to phase loss.
According to claim 1,
The low-voltage cable is connected through a movable cable drum device,
The moving cable drum device,
Including a cart that moves or fixes in a state of being placed on a cart that fixes both sides of the axis of the drum device body that winds or unwinds the low-voltage cable,
Wheels for movement are mounted on the lower part of the cart,
A separator is formed that divides the area where the low-voltage cable is wound into two areas so that both ends of the start and end points of the cable can be used in a state in which only part of the low-voltage cable is unwound,
In addition, a handle capable of rotating the drum device body to unwind or rewind the low voltage cable is formed on one side of the drum device body.
The method of claim 1, wherein the branching device,
As a portable low-voltage cable branching device that can be connected to two terminals for each phase of a mobile transformer train,
It is formed in a form housed in a case with a portable handle formed therein,
Equipped with a grounding terminal,
It is formed in a form that makes it easy to connect and separate low-voltage cables by using a connecting material that allows one-touch connection.
It is formed in three circuits to enable low-voltage cable branching in branch lines,
In addition, the lead-in and out part of the low-voltage cable is formed so that connection can be disconnected in a one-touch method by rotating the lead wire once in a spiral form, and has a function to prevent loosening due to twisting of the low-voltage cable. Uninterrupted power distribution construction method.
The method of claim 1, wherein the image inspection blocking device,
It is formed to be stored in a case having a handle for carrying,
In addition, when coupled with the connection terminal of the low-voltage cable, it is formed so that the connection can be disconnected with one rotation, and the uninterruptible power distribution construction method of the low-voltage line, characterized in that it has a function to prevent loosening due to twisting of the low-voltage cable.

Images