CN108336734B - Distribution network low-voltage line laying and load access device and access method thereof - Google Patents

Abstract

The invention discloses a distribution network low-voltage line laying and load accessing device and an accessing method thereof. The invention is convenient for realizing the conditions according to the local conditions, has small construction coordination difficulty, low construction resistance risk, high cost performance, economy and feasibility, greatly reduces the probability of fire hazard occurrence, has short power supply distance, good voltage quality and low line loss, improves the efficiency of maintenance, overhaul and meter expansion, reduces the number of electric poles off line, reduces the wire connectors, reduces the personnel pole climbing probability and reduces the operation safety risk.

Description

Distribution network low-voltage line laying and load access device and access method thereof

Technical Field

The invention belongs to the technical field of distribution line equipment, and particularly relates to a distribution network low-voltage line laying and load access device and an access method thereof.

Background

Because of city construction planning, a large number of private buildings at the two sides of commercial streets of partial urban areas, county-level cities, villages and towns and the like are not reserved with electric power facility channels. The power facilities such as the power transformer, the electric pole, the overhead conductor and the like are all arranged on two sides of a road, and through many years of commercial development, various industries and various advertising door heads tightly wrap and encapsulate the power facilities such as the wall-following power low-voltage circuit, the electric energy meter and the like. Thus causing significant safety hazards and problems:

1) Fire hazard: the advertisement door head is mainly encapsulated by inflammable substances such as wood, plastic and the like, and the wires and the meter are tightly wrapped, so that fire accidents are easily caused by various reasons;

2) Hidden danger of human body electric shock: the advertisement door head is a metal framework, and the power line is extruded and wrapped to cause the faults of short circuit, electric leakage, wire disconnection, zero line electrification and the like caused by the insulation damage of the lead, so that the personal electric shock accident is directly or indirectly caused;

3) Hidden trouble of damage to electrical equipment: the wrapped power line is extremely easy to cause defects such as short circuit, broken wire, poor contact, ground entering of a live wire and the like, and causes accidents of overvoltage and overcurrent damage of power departments and consumer electrical equipment;

4) The construction of a low-voltage power supply line is difficult: the power line is used as a life line for production and living in the current society, the responsibility of safe and reliable power supply is great, the low-voltage line in the door head is lost over time, the problems of frequent fault stop, overload heating, low voltage, limitation of installation and the like are more remarkable, and the reconstruction of the line is unprecedented. However, due to the problems of serious package of urban building planning and advertisement door heads, and the like, the construction and development of lines are seriously restricted by the existence of the problems of construction resistance of individual users personal gain and the like;

5) The inspection, maintenance and business expansion are difficult: a) daily inspection and maintenance work cannot be carried out, b) fault rush-repair is difficult, the situation becomes extremely complex, the risks of electric shock, burn and high-falling work in production work are extremely high, the work safety of electric power workers is seriously threatened, c) the problems of frequent power failure, slow re-electricity, low voltage and the like frequently occur, so that electric power users cannot safely and safely use electricity, and related complaints are more;

6) High line loss and difficult management and control: some low-voltage line sections which are tightly packed are even packed for more than ten years, various heating hidden troubles such as line overload, poor contact of joints and the like can not be rectified and eliminated, and the artificial wire packing can also take advantage of illegal electricity stealing actions, so that the line loss of the relevant transformer area is higher, the running loss of the relevant transformer area is immeasurable, and the national asset loss is caused.

Disclosure of Invention

The invention solves the technical problems that: a low-voltage line laying and load accessing device for distribution network and its accessing method are provided to solve the problems in the prior art.

The technical scheme adopted by the invention is as follows: the utility model provides a join in marriage net low pressure circuit and lay and load access arrangement, includes the junction box, junction box fixed connection just is located advertisement door top on the wall, and the inlet wire end is connected to on the nearest pole distribution line through four cables, and the exit end has a plurality of user single-phase ammeter and user power ammeter through power supply cable connection, and power supply cable lays outside advertisement door.

Preferably, the upper side is provided with the three-phase main bus bar that is trapezoidal step and arranges in above-mentioned junction box, be connected with three-phase bus bar wiring board on the three-phase main bus bar and stretch out the top, three-phase main bus bar is connected to 3P air circuit breaker inlet wire port and is connected to the three-phase ammeter bus bar that the downside is trapezoidal step and arranges through the cable respectively through the wire row, three-phase ammeter bus bar is connected with a plurality of 2P air circuit breakers, 2P air circuit breaker unsettled is connected to on the junction box and with 3P air circuit breaker front and back arrangement, 3P air circuit breaker outlet wire end is connected to user's power ammeter, 2P air circuit breaker outlet wire end is connected to the single-phase ammeter of user, still include the zero-phase busbar of installation in the junction box right side wall, zero-phase busbar is connected to zero-phase ammeter busbar through the wire, zero-phase ammeter busbar is connected to every 2P air circuit breaker through the wire.

Preferably, the three-phase main bus bar is fixedly connected to the junction box body through two symmetrical first trapezoidal insulating columns, and the upper sides of the two first trapezoidal insulating columns are fixedly connected with a first insulating plate.

Preferably, the three-phase ammeter busbar and the zero-phase ammeter busbar are fixedly connected to the suspension frame through two symmetrical trapezoidal insulating columns II, the suspension frame is fixedly connected to the wiring box body, the insulating plates II are fixedly connected to the upper sides of the two trapezoidal insulating columns I, and the 2P air circuit breaker is fixedly connected to the suspension frame.

Preferably, the zero-phase busbar is fixedly connected to the junction box body through an insulating column.

Preferably, the bottom of the junction box is fixedly connected with a bracket, the bracket comprises a rear side fixing frame and a bottom connecting frame which are fixedly connected with each other in a vertical mode, the rear side fixing frame is fixedly connected to a wall, and the bottom connecting frame is provided with a strip-shaped hole for connecting the box.

Preferably, the front end of the bracket extends out of the junction box body to be capable of being hung with an insulating ladder, reinforcing diagonal braces are arranged on two sides of the junction box body, and connecting holes for connecting the strain clamps of the main inlet wires are formed in the diagonal braces.

Preferably, the low-voltage line laying and load access device of the distribution network further comprises a hoisting frame detachably connected with the side face of the support.

Preferably, the lifting frame comprises a lifting rod and a lifting pulley, wherein the lifting rod is an inverted L-shaped frame, the lower end of the lifting rod is fixedly connected to the bracket through two bolts, and the horizontal end part of the upper end of the lifting rod is connected with the lifting pulley.

An access method of a low-voltage line laying and load access device of a distribution network comprises the following steps: the method comprises the steps that four wires are led from a nearest low-voltage pole to enter a wiring box body, the wiring box body is used as a central point for power supply access and load dispersion, each ammeter wiring box body connected with loads controls the power supply range of 10 households of units of 14 meters and 4 door faces, a special box to a user ammeter adopts an electricity larceny prevention jointless low-voltage cable, wires are led out of the advertising door head along the straight line between a second floor and the advertising door head, the wiring box body is grounded, a 16 square wire is led out from a box shell, the 16 square wire is led back to a fire-taking pole in an overhead mode, and 1.5 meter grounding angle steel is adopted at the root of the pole to enter the ground.

The invention has the beneficial effects that: compared with the prior art, the invention has the following effects:

1) The construction coordination difficulty is small, the construction resistance risk is low, the cost performance is high, and the construction coordination method is economical and feasible according to local conditions: a) The low-voltage main line is overhead to enter the box along the wall, so that the risk of worker blocking is low, and the coordination difficulty is low; b) The width of the box body can be set to be 0.65 meter, the distance between the windows is about 1.8 meter, and the space for installing the special wiring box for the ammeter is abundant; c) The installation height is only 0.3-0.5 meter higher than that of the conventional laying mode, so that the maintenance and the overhaul are convenient; d) The circuit laying distance is short, economical and feasible, the voltage drop is small, and the voltage quality is good. The occupied space is small, each outlet line of the box body is provided with an open protection design, and the occurrence probability of fire hazards is greatly reduced; e) The hidden danger of hot spot of lapping that the straight trunk line of front line of the original table caused of effectively avoiding, concentrate the original scattered hidden fire spot of lapping in the case and be convenient for manage. The air-break compression joint type connection is more reliable, the heating hidden trouble is effectively treated, the line loss is reduced, and the fault and power failure are reduced; f) The electric distribution box body is characterized in that a small 16 square wire is led to the shell of the electric distribution box body and returns to the fire-carrying electric pole in an overhead mode, and 1.5 m grounding angle steel is adopted at the root of the electric pole to enter the ground, so that the safety is higher;

2) Each outlet of each household ammeter of the wiring box body is provided with an idle overload and overcurrent protection, so that the occurrence probability of fire hidden danger is greatly reduced;

3) Aiming at the problems of poor voltage quality and high line loss which are easily caused by the low-voltage wiring load access mode of the original 'one-line connection and lantern hanging', the bottom of the wiring box body can adopt middle outgoing lines, the two ends diffuse left and right radiation, the power supply distance is short, the voltage quality is good, and the line loss is low;

4) The efficiency of maintenance, overhaul and meter expansion is improved, meanwhile, the number of electric poles coming off is reduced, the wire joints are reduced, the probability of personnel climbing the poles is reduced, and the operation safety risk is reduced;

5) Aiming at the problem of hot hidden danger of hair overlapping caused by directly overlapping a low-voltage main line on the front line of an original meter, the load overlapping points which are extremely dispersed and hidden originally are concentrated in the box so as to be convenient to manage, the air-break compression joint type connection is more reliable, the hot hidden danger can be effectively controlled and eliminated, the line loss is reduced, and the fault and power failure are reduced;

6) The fault power failure is reduced, the power supply reliability is improved, and the power consumption satisfaction of users is improved;

7) The wiring box body has strong heat dissipation performance, reasonable space and good man-machine effect, and is convenient for the development of load access, overhaul and other works;

8) Aiming at the load access characteristics of the single-phase electric energy meter and the power electric energy meter, the minimum safety distance between the wire inlet and outlet and the circuit breaker and the operation space in the box body of the operator are set according to the requirement of the section load bearing, so that the space position is safe and reasonable, and the man-machine power is excellent;

9) Compared with the traditional novel box of the load junction box, each switch of the novel box has independent cylinder space, the space utilization rate is higher, the load inlet and outlet wires are orderly and mutually non-staggered, the safety of air main insulation short circuit prevention between wires is improved, the vertical outlet wire mode is beneficial to smooth air flow in the box, and the heat dissipation performance in the box can be effectively enhanced by matching with the heat dissipation air rail of the box;

10 The three-phase main bus bar and the three-phase ammeter bus bar which are arranged in a step manner are convenient for clear identification and visual and reliable design of phase separation sequences, so that single-phase meter load access is no longer blind, standard and safe, and hidden danger of three-phase unevenness of a transformer is effectively treated from the source;

11 The live operation can be easily converted into safe power failure operation, the safety is improved, and meanwhile, the work difficulty of repairing the door head, removing the obstacle and checking the defect is reduced. The convenient and quick access mode improves the work efficiency of meter loading and power connection;

12 The hidden danger of hot spot of lapping caused by the straight lapping of the front line of the original meter is effectively avoided, and the original scattered and hidden lapping points are concentrated in the box for convenient management. The air-break compression joint type connection is more reliable, the heating hidden trouble is effectively treated, the line loss is reduced, and the fault and power failure are reduced;

13 The air-break protection tripping can cut off short-circuit current in time, effectively prevent accidents and events such as fire disaster, equipment damage and the like caused by short-circuit, avoid the influence and impact of branch faults on an upper-level power supply, reduce loss and improve power supply availability;

14 The wiring box body is supported by the support, the supporting installation safety of the wiring box body is further ensured, the front end extends out of the box body for one section, on one hand, the outgoing lines of the bottom power ammeter and the single-phase ammeter are facilitated, on the other hand, the installation of the box body, the safe access of a main incoming wire, the liberation of hands by personnel when a ladder is used for operation and maintenance on the box body, rush repair, meter load access and other operations in the future are ensured, the insulation ladder is convenient to be hung and stand for the maintenance and loading and unloading of the distribution box, the operation safety is higher, the man-machine effect is good, the working efficiency is improved, the 'high-falling' safety accidents are effectively prevented, and the binding and the hanging of a safety belt and the binding and the hanging of two insurance are facilitated;

15 The detachable hoisting frame is adopted, and is arranged on the support, so that the rapid installation of the wiring box body can be realized, the time and the labor are saved, the operation safety is high, the assembly and the disassembly are convenient, the repeated use is realized, the equipment cost is reduced, the use of large-scale hoisting tools such as a hoisting car and the like on more sections of a man-car is effectively avoided, the construction difficulty is reduced, and the installation efficiency is improved;

16 The fixing device is used for fixing the strain clamp of the main lead and the lead wires of the hardware fitting at different angles, so that the main lead wires are more flexible, the construction height is lower, the main lead wires are farther away from a window of a user, and the main lead wires are favorable for future maintenance and overhaul;

17 The diagonal brace is provided with a connecting hole for connecting the main lead strain clamp and fixing the main lead strain clamp and the hardware fitting at different angles, so that the main lead is more flexible, the construction height is lower, the main lead is farther away from a window of a user, and the main lead is favorable for future maintenance and overhaul;

18 The support of the frame structure is adopted, and the support stability is high.

Drawings

Fig. 1 is a schematic structural diagram of an access device;

FIG. 2 is a schematic diagram of a connection structure of a conventional 50m junction box;

FIG. 3 is a schematic view of the connection structure of the junction box;

FIG. 4 is a schematic view of the junction box structure;

FIG. 5 is a schematic view of the connection structure of the components installed in the junction box (with the box shell removed);

FIG. 6 is a schematic view of the connection structure of the mounting components in the junction box;

FIG. 7 is a schematic diagram of the structure of the case connecting bracket;

FIG. 8 is a schematic view of a stent structure;

FIG. 9 is a schematic diagram of the front view of the case;

FIG. 10 is a schematic diagram of a left-hand structure of the case;

FIG. 11 is a schematic left-hand structural view of the case;

FIG. 12 is a schematic diagram of the front view of FIG. 5;

FIG. 13 is a right side elevational schematic view of FIG. 5;

FIG. 14 is a schematic top view of the structure of FIG. 5;

FIG. 15 is a schematic view of a front view of the bracket;

FIG. 16 is a schematic left-hand structural view of the bracket;

FIG. 17 is a schematic top view of the bracket;

FIG. 18 is a schematic view of a front view of a hoist frame connection;

FIG. 19 is a schematic view of a left-hand structure of a connection of a hoisting frame;

FIG. 20 is a schematic view of a strain clamp structure for connecting the left end of a bracket to a main inlet wire;

Fig. 21 is a schematic diagram of a strain clamp structure for connecting the right end of a bracket to a main inlet wire.

Detailed Description

The invention will be further described with reference to the accompanying drawings and specific examples.

Example 1: as shown in fig. 1-21, a low-voltage line laying and load access device for a distribution network comprises a wiring box 1, wherein the wiring box 1 is fixedly connected to a wall 2 and is positioned above an advertising door head 3, a wire inlet end is connected to a distribution line on a nearest electric pole 4 through four cables, an outlet end is connected with a plurality of user single-phase electric meters 6 and user power electric meters 7 through power supply cables 5, and the power supply cables 5 are laid outside the advertising door head 3.

Preferably, the upper side in the above-mentioned junction box 1 is provided with the three-phase main bus bar 8 that is trapezoidal step and arranges, three-phase main bus bar 8 goes up through insulating support column 41 fixedly connected with three-phase bus bar wiring board 9 and stretches out the top, three-phase main bus bar 8 is connected to 3P air circuit breaker 10 inlet wire port and is connected to the three-phase ammeter busbar 11 that the downside is trapezoidal step and arranges through the cable respectively through the wire row 9, three-phase ammeter busbar 11 is connected with a plurality of 2P air circuit breakers 12,2P air circuit breaker 12 unsettled and is connected to junction box 1 and arrange around with 3P air circuit breaker 10, 3P air circuit breaker 10 outlet wire end is connected to user power ammeter 7,2P air circuit breaker 12 outlet wire end and is connected to user single-phase ammeter 6, still include the zero-phase busbar 13 of installation in the junction box 1 right side wall, zero-phase busbar 13 is connected to zero-phase busbar 14 through the wire, zero-phase busbar 14 is connected to every 2P air circuit breaker 12 through the wire, the junction box surface coats the insulating paint, the insulating.

Preferably, the three-phase main bus bar 8 is fixedly connected to the junction box 1 through two symmetrical first trapezoidal insulating columns 15, and an insulating plate 16 is fixedly connected to the upper sides of the first two trapezoidal insulating columns 15.

Preferably, the three-phase electric meter busbar 11 and the zero-phase electric meter busbar 14 are fixedly connected to the suspension frame 18 through two symmetrical trapezoidal insulating columns 17, the suspension frame 18 is fixedly connected to the junction box body 1, and the insulating plates two 19,2P and the air circuit breaker 12 are fixedly connected to the upper sides of the two trapezoidal insulating columns 17.

Preferably, the zero-phase busbar 13 is fixedly connected to the second mounting and fixing plate 31 through the insulating column 20, and the second mounting and fixing plate 31 is fixedly connected to the side wall of the junction box 1.

The nylon plastic cable waterproof connector 38 is arranged on the left side and the right side of the upper end of the wiring box body 1, the power ammeter load wire outlet hole 36 and the single-phase ammeter load wire outlet hole 37 are arranged at the bottom of the wiring box body 1, the radiating holes 35 are formed in the left side wall and the right side wall of the wiring box body 1 and the lower portion of the front end of the top cover 34, the top cover and the radiating holes communicated with each other in the side face are convenient for the wiring box body to radiate heat, the hanging rings 39 are arranged on the left side and the right side of the upper outer portion of the wiring box body 1, the grounding bolts 40 are arranged on the right side of the wiring box body 1, and the grounding bolts 40 are connected with a grounding wire.

The trapezoid insulating column I15, the suspension frame 18 and the 3P air circuit breaker 10 are fixedly connected to the mounting and fixing plate I32, and the mounting and fixing plate I32 is fixedly connected to the inner rear side wall of the box body 1

Preferably, the bottom of the junction box 1 is fixedly connected with a bracket 21, the bracket 21 includes a rear side fixing frame 22 and a bottom connecting frame 23 which are fixedly connected with each other vertically, the rear side fixing frame 22 is fixedly connected to the wall 2, the bottom connecting frame 23 is provided with a strip-shaped hole 24 for connecting the box, the front end of the bracket 21 extends out of the junction box 1 to form a section, an insulating ladder can be hung on the outer side, reinforcing diagonal braces 29 are arranged on two sides of the bracket, phi 14 connecting holes 30 for connecting a main inlet wire strain clamp 33 are formed in the diagonal braces 29, phi 14 connecting holes for connecting a main inlet wire strain clamp are formed in the front end of the bottom connecting frame 23, the bracket and the diagonal braces are made of a plurality of angle steels L50X5, each part of the bracket is connected in a welding mode, the bracket and the diagonal braces are connected and firm by adopting M12 bolts, the front side length of the main bracket exceeds the box 10CM, the front edge bracket and the two ends and the diagonal braces of the insulating ladder can be hung reliably to provide a safety belt while the wire outlet of the bottom of the box is not influenced, the middle section of the bracket is hung, the two ends of the diagonal braces are used for hanging wires, the temporary wall side brackets are hung, and the temporary wall side brackets are used for installing the bracket to punch holes. The four bracket angle steels on the wall side are totally provided with 8 mounting holes for fixing.

The bearing capacity of the bracket is 75kN,1kN is approximately equal to 100kg, 75kN is approximately equal to 7500kg, 2 diagonal braces with 45 degrees of angle steel which is L50X5 are arranged on two sides of the bracket, the bearing capacity of the bracket is stronger, the bracket is fixed by 8M 12X105 expansion bolts, the brick wall of a city building is generally 75 # or 100 # mortar strength brick wall, 1M 12X105 expansion bolt can reach 440kg of tension and 245kg of shear force, and 8M 12X105 expansion bolts can reach 3520kg of tension and 1960kg of shear force. The weight of the electric meter junction box is 30kg according to actual work; 2 workers weighed 160kg; the self weight of the multifunctional bracket is 20kg; the insulating ladder of 8 meters weighs about 30kg, and the weight of the insulating ladder in the hanging and supporting state is about 10kg; main incoming line tension 80kg; the total weight of the outlet line is 355kg, which is 25kg in the outlet line full-out state.

The calculation is carried out by 1960kg of expansion bolt shearing force with the minimum bearing capacity, the total weight of the box body installation and daily operation can be about 6 times of force, and the safety can be ensured.

Preferably, the low-voltage line laying and load access device of the distribution network further comprises a lifting frame 25 detachably connected with the side surface of the bracket 21.

Preferably, the hanging frame 25 comprises a hanging rod 26 and hanging pulleys 27, the hanging rod 26 is an inverted L-shaped frame, the lower end of the hanging rod 26 is fixedly connected to the support 21 through two bolts 28, the upper horizontal end of the hanging rod is connected with the hanging pulleys 27, the hanging rod is made of L50x5 angle steel, the length of the hanging rod is 1.5M, the width of the hanging rod is 0.5M, 2 phi 14 holes are formed in the lower section of the hanging rod for installing M12 bolts, a 0.4M 50x5 flat steel diagonal draw rod is welded at the top of the hanging rod for enhancing the reliability of the hanging rod, and 1 phi 14 hanging hole is formed in the upper end of the hanging rod for installing the hanging pulleys.

The use principle of the hoisting frame 25: when the wiring box body is installed, firstly, an operator uses a ladder to fix the bracket on the wall surface, then uses two M12 bolts to fix the detachable temporary suspender on the suspender fixing hole on the right side of the bracket, and uses a pulley and a rope at the top of the hoisting frame to hoist the ammeter wiring box body to the installation position, and then uses the bolts to firmly fix the wiring box body, so as to detach the temporary suspender to complete the installation.

An access method of a low-voltage line laying and load access device of a distribution network comprises the following steps: four wires are led from the nearest low-voltage pole to enter a wiring box body, the wiring box body is used as a central point for power supply access and load dispersion, each ammeter wiring box body connected with the load controls the unit 10-family power supply range of 14 meters and 4 door faces, the wiring box body adopts an anti-electricity-theft non-joint low-voltage cable to a user ammeter, wires are linearly arranged between a second building and an advertising door head along the outside of the advertising door head, and a power channel and facilities are hung, and the coverage and hanging of the power channel and facilities are forbidden-! The warning board is characterized in that the wiring box body is made of stainless steel, the wiring box body is grounded, a 16 square wire is led to the box shell in an overhead mode, returns to the fire-taking electric pole, and is grounded by adopting 1.5 m grounding angle steel at the root of the electric pole.

The above description is only an example of the embodiment of the present invention, and the scope of the present invention is not limited thereto. Variations and alternatives can be readily ascertained by one skilled in the art within the scope of the present disclosure, which is intended to be within the scope of the present disclosure. For this purpose, the scope of the invention shall be subject to the scope of the claims.

Claims (3)

1. The utility model provides a join in marriage net low pressure circuit and lay and load access device which characterized in that: the intelligent advertising door comprises a wiring box body (1), wherein the wiring box body (1) is fixedly connected to a wall (2) and is positioned above an advertising door head (3), a wire inlet end is connected to a distribution circuit on a nearest electric pole (4) through four cables, an outlet end is connected with a plurality of user single-phase electric meters (6) and a plurality of user power electric meters (7) through power supply cables (5), and the power supply cables (5) are laid outside the advertising door head (3); the three-phase main bus bar (8) which is arranged in a trapezoid step is arranged on the upper side in the wiring box body (1), a three-phase bus bar wiring board (9) is connected to the three-phase main bus bar (8) and extends out of the upper side, the three-phase main bus bar (8) is connected to a wire inlet port of the 3P air circuit breaker (10) and is respectively connected to three-phase ammeter bus bars (11) which are arranged in a trapezoid step on the lower side through cables, the three-phase ammeter bus bars (11) are connected with a plurality of 2P air circuit breakers (12), the 2P air circuit breakers (12) are connected to the wiring box body (1) in a suspending manner and are arranged front and back to the 3P air circuit breakers (10), a wire outlet end of the 3P air circuit breakers (10) is connected to a user power ammeter (7), the wire outlet end of the 2P air circuit breakers (12) is connected to a user single-phase ammeter (6), and the three-phase ammeter bus bar (13) which is arranged in the right side wall of the wiring box body (1) is connected to a zero-phase ammeter bus bar (14) through wires; the three-phase main bus bar (8) is fixedly connected to the wiring box body (1) through two symmetrical trapezoid insulating columns I (15), and an insulating plate I (16) is fixedly connected to the upper sides of the two trapezoid insulating columns I (15); the bottom of the wiring box body (1) is fixedly connected with a bracket (21), the bracket (21) comprises a rear side fixing frame (22) and a bottom connecting frame (23) which are mutually and vertically fixedly connected, the rear side fixing frame (22) is fixedly connected to the wall (2), and the bottom connecting frame (23) is provided with a strip-shaped hole (24) for connecting the box body;

The three-phase ammeter bus bar (11) and the zero-phase ammeter bus bar (14) are fixedly connected to a suspension frame (18) through two symmetrical trapezoidal insulating columns II (17), the suspension frame (18) is fixedly connected to the wiring box body (1), an insulating plate II (19) is fixedly connected to the upper side of the two trapezoidal insulating columns II (17), and the 2P air circuit breaker (12) is fixedly connected to the suspension frame (18);

the front end of the bracket (21) extends out of the wiring box body (1) to be capable of being hung with an insulating ladder, reinforcing diagonal braces (29) are arranged on two sides of the insulating ladder, and connecting holes (30) for connecting a main lead strain clamp are formed in the diagonal braces (29);

the lifting frame (25) is detachably connected with the side face of the bracket (21);

The lifting frame (25) comprises a lifting rod (26) and a lifting pulley (27), the lifting rod (26) is an inverted L-shaped frame, the lower end of the lifting rod is fixedly connected to the bracket (21) through two bolts (28), and the horizontal end part of the upper end of the lifting rod is connected with the lifting pulley (27) which hangs.

2. A low-voltage line laying and load access device for a distribution network according to claim 1, wherein: the zero-phase bus bar (13) is fixedly connected to the junction box body (1) through an insulating column (20).

3. An access method for a low-voltage line laying and load access device of a distribution network according to any one of claims 1-2, characterized in that: the method comprises the following steps: the method comprises the steps that four wires are led from a nearest low-voltage pole to enter a wiring box body, the wiring box body is used as a central point for power supply access and load dispersion, each ammeter wiring box body connected with loads controls the power supply range of 10 households of units of 14 meters and 4 door faces, a special box to a user ammeter adopts an electricity larceny prevention jointless low-voltage cable, wires are led out of the advertising door head along the straight line between a second floor and the advertising door head, the wiring box body is grounded, a wire with the square of not less than 16 square is led in a box shell, the wire returns to a fire-taking pole in an overhead mode, and 1.5 meter grounding angle steel is adopted at the root of the pole to enter the ground.