Installation of self-supporting insulated wires

Gradually, overhead power lines with bare wires go to the past. It is understandable how high they would not be mounted, there is always a danger of failure electric shock. Given that the current strength in such lines is quite large, because they feed not one house, but sometimes whole streets and even populated areas, accidents in these areas lead to serious consequences, up to lethal outcomes. Developments in the field of cable insulation allow the use of a single, self-supporting insulated wire with separate insulation for each live and auxiliary wire that is capable of withstanding atmospheric effects for a long time.

Description of CIP

By type self-supporting insulated wire is the usual stranded stranded power cable  without general isolation. AT cable SIP-1  isolation on the zero carrying wire is missing, all other brands have mandatory isolation on all wires. SIP-1, SIP-2 and SIP-3 and their modifications differ in that the carrier or single core (as in the case of SIP-3) is equipped with a rigid steel core, these cable grades are used for laying air lines of considerable length. SIP-4 and SIP-5 do not have cores in their veins and can be used at short distances, for example for electrical connection to the building's switchboard. Isolation of the first and fourth brands of the cable is made of extruded light-resistant thermoplastic polyethylene, while in some modifications and in the manufacture of other brands only "cross-linked" polyethylene is used. These technologies of plastic production make it possible to obtain a coating that is resistant to weathering and stretching, as well as to the heating of conductors in critical situations.

Benefits

Installation of SIP in comparison with bare aluminum-steel wires has only one significant drawback: the cost of laying such lines is somewhat more expensive. While compared to the cables fixed to the carrier cable, it is possible to slightly reduce the price and reduce the overall complexity of the installation.

Among the main advantages are called increased electrical safety, independence of conductor characteristics from atmospheric conditions and relative simplicity of installation. The insulation of the phase wires not only protects the metal from the environment, but also provides protection for the surrounding objects and creatures from electric shock.

In addition, insulated wires lack the deterioration of conductive characteristics in the case of icing, like their "bare" predecessors, and they can not be "swept" by any wind. Using a special armature and a tool for mounting the self-supporting insulated wire, the specialist is able to accomplish almost the entire process of work, in the presence of installed supports.

Application

The brands of self-supporting wires are divided not so much in their appearance as in the field of application. In general, SIPs are designed for transmission and distribution of electricity in networks alternating current  voltage up to 35 kV. The wires of the SIP-1 brand are used in the main air lines up to 1 kV. Due to the special core carrying an aluminum alloy with a steel core, such wires can withstand severe loads for a long time.

The installation of self-supporting insulated wire for the SIP-1 supports is most popular when laying open air lines outside populated areas of the temperate climatic zone. For regions with high humidity, as well as in densely built-up areas, it is more appropriate to use SIP-2, which, in contrast to SIP-1 with bare zero, is completely isolated.

Carrier Isolation zero wire  allows to increase the electrical safety of the line as a whole, besides the application of the technology of polyethylene cross-linking expands the climatic limits of the application of these wires.

SIP-3 is made with one dwelling especially for the laying of high-voltage transmission lines. SIP-4 and SIP-5 are made without a core, therefore their use is limited to short sections connecting specific consumers to the main air line, as well as conducting small sections of electrical wiring on the facade and inside buildings.

Preparation for work

Mounting the SIP on the supports is not too different from the technologies used earlier. For laying a new line, first of all, it requires clearing the territory of trees and shrubs. The next stage will be the installation of bearing supports. At this stage, for ease of installation, anchor brackets  before placing the support in a vertical position. In this case, tapes of steel with anti-corrosion properties are used, fixed with a clamp-on clutch. Fastening of wires to supports and among themselves is made by means of the special armature which is issued specially for installation СИП.

Safety precautions

When installing the SIP lines, employees are required to comply with all safety requirements:

• Standard requirements for outdoor work.
• Preparation of the territory where the work is carried out, clearing of bushes, trees and debris.
• Requirements for electrical safety when working with installations up to 1000 V and above, depending on the voltage of the line being laid.
• Mandatory introductory at the beginning of work and daily briefing for each employee involved in the installation of CIP.
• The use of PPE according to existing norms and GOSTs, the use of only serviceable equipment and tools.
• Protective and marking fencing of the work site.
• Safety at work at height, working hoists and other means.
• Additional safety requirements when using special mechanized machinery and devices.

CIP Installation Rules

Special requirements are imposed on the deployment of drums: the wire should not touch the ground or structures during installation, in order to avoid violation of insulation. On sections over 100 m only mechanized rolling is applied directly from the drum installed on the machine. Another feature of laying SIP lines is the use of a block system to suspend the cable and its subsequent stretching. These and other operations require special tools and tools for the installation of SIP, among which scissors for steel bands and hydraulic for wires, crimping for sleeves, dynamometers, winches and others. The remaining requirements for the laying of overhead lines SIP are regulated by the PUE (set of rules for the device electrical installations), as well as GOST R 52373-2005.

CIP to distribution panel

Laying branches from the main power line to a private house or other structure will require additional costs from the owner in the form of planning, preparing documents and signing an agreement for the electrification of the site. In cases where the nearest power line support is located further than 25 m from the planned electricity distribution and registration board, additional supports will be required at the expense of the owner. The most advantageous is to equip the guard on the very support, and the electrical connection to the site to be carried underground under a trench.

According to the needs of the homeowner, you can conduct both a single-phase line and a three-phase line. Taking into account the planned load, it is necessary to select the appropriate wire cross section. These sections usually use SIP-2A or softer wires of SIP-4 and SIP-5 grades without a core with a steel core. The reinforcement allows not only to fix the wire to the building, but also to lead small sections of the line directly along the facade.

Installation of this site is best entrusted to the specialists of the company supplying consumers with electricity in your region. They will have to sign the act on electrification and seal the counting equipment. In any case, this connection will have to be coordinated with the power supply enterprise.

Possible errors during installation

Insulation wire SIP is resistant to weathering, heating and tension, but extremely sensitive to mechanical stress. Therefore, it is forbidden to lay the wire on the ground and use rollers without special coating of polymers. Wire connection  is performed only between the supports, while the branches need to be carried out at the wire attachment points. Due to the special design of the piercing clamps, their reuse is unacceptable, other types of clamps are also prohibited, even if the wire is not stretched. Brackets are designed only for one fastening, for the same reason it is impossible to twist several SIPs in one bundle. Each line must be mounted separately. Checking the wire tension on the eye, without a dynamometer is unacceptable.

Conclusion

The self-assembly of the CIP of the cable from the post to the house in particular and the overhead lines as a whole seems to be a simple matter in technical performance. It is much more difficult to obtain permission to conduct such work, therefore, experts advise trusting this responsible business to professionals.

The abbreviation SIP stands for self-supporting insulated wire. Such a cable is used as a source of transmission and distribution electric power  in lighting networks with a voltage of up to 35 kilowatts.

The wire consists of several aluminum insulated cores and a carrier (zero) vein, twisted together. Insulation is a strong black polyethylene. The material is resistant to ultraviolet radiation.

Typically, the installation of the SIP wire is performed on highways and in sections where there are branches to residential buildings and all kinds of commercial buildings.

There are several types of this wire:

• 1 and 1 A;
• 2 and 2 A;
• 4 and 4 H;
• 5 and 5 N.

Depending on the type of product, the order according to which the SIP cable will be installed will be determined. It is better not to try to cope with the task yourself - it is unsafe and inefficient. Our masters will quickly arrive at the facility and will do their work for 5 points.

Cost of installation of CIP

The total cost of installing the SIP wire depends on many factors. For example, on the size of the section, the number of insulated wires, the size. Usually the amount is calculated based on the per meter of the product.

We offer our clients optimal conditions for cooperation. We have the lowest prices for this type of work. This makes us profitable different from most competitors. You can count on the high speed and exceptional quality of our services.

In the price-list the price for each type of service is indicated. If you have any questions, our consultants are always ready to give exhaustive answers to them. You will find that our offer is really unique. We will not let you down!

Advantages of using CIP

Many enterprises order the installation of self-supporting insulated wires. And all because this equipment has a lot of advantages. CIP air lines differ:

• Safety. This is due to the exclusion of contact with the elements conducting the current.
• High reliability. Even when equipment with grounded objects is in contact, the possibility of a short circuit is completely eliminated.
• Economical. It is enough to make a qualitative installation of the CIP of the cable from the post to the house, so that the structure will last a long time.
• Low losses. Induction resistance in such lines is much less than in traditional ones.

The only condition - the installation of wires SIP on the poles should be performed with the use of a set of tools and equipment. All this is at the disposal of our specialists.

It is better to entrust the mission to experienced professionals, otherwise the result will be very different from the one conceived. In order to correctly erect a power line with a CIP wire, several rules must be observed:

• The route of overhead lines must be prepared for the forthcoming work. It is necessary to remove branches of trees that interfere with the installation of equipment.
• It is necessary to remove worn out transmission lines before the work on installing new supports begins.
• Eliminate the possibility of mechanical damage to the insulation of the product. Do not come in contact with concrete structures, tree branches, or earth.
• To attract to the works only experienced masters having the necessary qualifications.
• To install the CIP wire on supports at an air temperature of at least 20 degrees.
• Do not overtighten the product.
• Perform control of each stage of work.

Our masters often travel to various sites in Moscow. They are well versed in their business, aware of the rules of safety. We guarantee that the specialists will cope with the task impeccably.

Sequence of installation

Suppose you need to hold a cable from the pillar near the house. The action will occur in several stages:

• clearing of the adjacent territory, preparation of the site;
• manual rolling of wires;
• cable connection;
• connection to the highway.

Connection is made by ground or underground method. The second option is preferable, because then the probability of damage to wires due to fire, rain, wind and so on is excluded.

The cable is lowered into a specially excavated trench depth of at least 80 centimeters. The wire must necessarily be hidden in a sleeve made of metal or plastic - its product from the negative effects of moisture. After the trench is falling asleep, the site should be noted with the help of lighthouses.

Self-supporting insulated wire (SIP) is used in various areas, including in private construction. The obvious advantages and performance characteristics of the cable allow you to carry out the installation yourself, but only if the details of the process are agreed with the energy company.

Construction of self-supporting insulated wire  - a few aluminum cores, which are twisted together and protected from above by insulating material. As insulation, stabilized polyethylene is used. Thanks constructive features  The cable can be used for laying branches of networks, as well as the main trunk lines. Often, wires of this type are used in private construction for the installation of power in hozpostroikah or country houses. In this regard, the question of how to independently mount the cable is relevant.

Advantages of CIP

This type of cable is often used for building electrical networks in private construction. Experts explain this not only by the relative simplicity of installation, but also by the number of advantages that a self-supporting insulated wire has over other types of cables. The obvious advantages of SIP include the following features:

• safety of installation by one's own hands - at observance of technical requirements for installation work, self-laying of the wire is absolutely safe;
• reliability - the voltage is transmitted by cable in any conditions;
• variability - SIP has different types of section, so it can be selected for any needs;
• resistance to external factors - the wires are made of special materials that will withstand the influence of atmospheric phenomena. Even at very low air temperatures they remain flexible and soft.

SIP can be mounted manually, but only with the presence of similar skills. If you have never been involved in the installation of power grids on your own, do not take risks and seek assistance from specialists competent in this field.

How to mount self-supporting insulated wire

The installation of this type of cable is quite simple. It can be done independently, but only subject to the requirements of safety. Preliminary it is necessary to coordinate the installation of the wire with an authorized state agency. If you get all the permissions and are ready to mount a self-supporting insulated power wire, then you need to follow the following sequence:

• first choose the wire cross section. For household needs, the most suitable is a SIP with a cross section of fifteen centimeters;
• prepare a special clamp with which you will fix the branches on the pole. It is not too difficult to fasten the branches with your own hands, but extreme care must be taken not to suffer;
• measure the distance from the post to the structure where you need to stretch the wires. If the distance exceeds twenty-five meters, install the support. Otherwise, installing the cable with your own hands takes much longer;
• then install the tensioner and return to the support to attach the fastening element, which will be responsible for the strength of the connection;
• go to the building where you will draw the cable, and install the anchorage on the outer wall (as close as possible to the roof). It must be selected in advance, based on the number of phases - the number of clamps must correspond to the number of phases.

At the final stage, it is necessary to conduct isolation works. The type of insulation should be chosen taking into account the features of the material from which the building was built.

If the farm building (or a country house) is built from a natural wooden massif, it is recommended to use PPE as insulation. These are caps made of a stabilized material based on plastic. If you are laying wires yourself to a house made of bricks or other material, you can leave the connection points open.

After the completion of the work outside the building, internal installation, which consists of only a few actions: the wire per meter is put inside, after which it branches.

Air line\u003e Line fittings NILED for VLI 0,4kV

The installation of self-supporting insulated wires (SIP) must be carried out in accordance with the technological maps or instructions. A special feature of the installation is the rolling of the SIP with the use of rolling rollers and a rope-leader. This technology protects SIP from mechanical damage during production, and is also the main condition for maintaining high operational performance of VLI during its entire service life.

The section describes the order of the work on rolling, fastening on supports, walls of buildings and structures, using insulated wires SIP-2 (old name SIP-2A).
The recommendations can be used by engineering and technical specialists, masters and electrolinesmen of organizations, joint-stock companies and firms that carry out the design, construction and operation of 0.4 kV overhead power lines with self-supporting insulated wires.
Installation of self-supporting insulated wire is recommended in accordance with the technologies given in the current technical and methodological documents, with the use of special linear reinforcement, mechanisms, devices and tools, at an ambient temperature of minus 20 ° C. The following basic requirements must be observed:
carefully prepare the track of the overhead line, perform clearing of the clearing, removing trees or large branches that interfere with the installation of supports, rolling and adjusting the wires;
  take measures to prevent damage to the insulating covering of wires during their rolling and adjustment, exclude touching the ground, concrete and metal structures, large branches of trees;
  rolling of wires to produce under tension;
  installation of wires is recommended to be commissioned by specially trained brigades of construction and installation or operational organizations;
  strictly observe the mounting forces and sagging arrows when adjusting the wires, do not allow the wires to be constricted.

Preparatory work
1. Before the construction of the line, the following work must be performed:

• the track of VLI has been prepared;
• assembled and installed in the design position of the support;
• the device of protection on transitions through engineering constructions is executed;
• on the entrances to the buildings the necessary reinforcement for the anchoring of the bushing wires is installed;
• delivered to the track drums with CIP and mechanisms for their rolling out.

• 5-bit electromagnetics (foreman);
• electro-linear operator of the 4th category - 1 person;
• 3-digit electroline; 2 people;
• driver of the 5th category - 1 person.

3. All electrolifters should be equipped with:

• construction helmet according to GOST 12.4.087-84;
• protective belt in accordance with GOST 12.4.089-86;
• mounting lasers according to TU 34-09-10129-89;
• mittens according to GOST 12.4.010-75.

Transportation of self-supporting insulated wire
1. Drums should be stored and transported in an upright position.
2. Drums with a wire must not be thrown when unloading from vehicles.
3. When moving drums from a SIP, avoid contact with sharp objects, for example when using a forklift.
4. When cutting cores of conductors or strands in general it is recommended to use sector scissors C 32.
5. After cutting into the free ends of the SIP harness, clamps should be applied E 778  or an electrical insulation tape to prevent further unwinding or loosening.
6. Do not remove the casing from the drum before it is installed to roll SIP.
7. When moving the drum on the ground, roll it in the direction indicated by the arrow on the side of the drum. When rolling off the SIP from the drum, the direction of its rotation should be the opposite.
8. Do not store drums on wet ground, sandy or damp places.
9. Do not drop the SIP on the ground, and then lift it and put it into the roller, the CIP is rolled from the drum.

Sliding of self-supporting insulated wire in an anchor span
1. The technology of roll-out of SIP includes the following types of work:

• installation of the drum;
• installation of a mechanism for rolling SIP off the anchor support;
• rolling rope-leader rollers;
• connection between cable and cable;
• uncoating;
• tension and fixing of SIP in the anchor span;
• adjustment of self-supporting insulated wire;
• installation of the suspension clamp on the supporting zero core.

2. Installation of the drum
Preferably, the drum is located close to the support on which the final adjustment of the sag and tie rods is made. The drum is installed at a distance from the support equal to, at least, the height of the support from the ground surface. Raskatku produce without jerking under tension. During rolling, the CIP must not touch the ground, metal and concrete structures.

3. Installation of the mechanism for rolling off the self-supporting insulated wire on the anchor support
Prior to the start of work on the rollout of the self-supporting insulated wire, a platform should be prepared at a distance of 10-15 m from the anchor support, and a rolling device (wheel-cable conveyor or cable jacks) must be installed and securely fixed on it. Roll the drum with a self-locking device to the rolling device, prepare a set of rolling rollers, rewind the cable rope from the bay to the metal coil. Lead-rope made of synthetic fibers with a diameter of 10 mm and a length of 30-50 m is designed for rolling SIP manually; rope made of synthetic fibers with a diameter of 12 mm and a length of 300 m or more, is intended for rolling with the use of mechanisms.

4. Roll-up of the rope-leader for rollers
The brigade is divided into two sections. The first link in the composition of the two electrolifters prepares the drum with the CIP for rolling. The second link in the composition of the three electrolines prepares the mechanism for the rollout of the SIP (gasoline engine, machine or other similar mechanism) and produces rolling of the leader cable with simultaneous suspension of the mounting rollers RT 2  and the intermediate suspension ES 1500E on the supports of the mounted section of the VLI. Lifting of the rope leader, and installation of rollers with intermediate suspension are made as you move along the anchor passage from the rolling mechanism to the drum with a CIP. Mounting of the intermediate suspension ES 1500E to the supports is carried out with the help of metal tape F207 and clips NC20; If there is a technological hole in the support, the intermediate suspension can be fixed to the bolt. Rollers RT 2 are attached to the hole in the bracket of the intermediate suspension ES 1500E. The composition of the kit and the number of rolling rolls of type RT 5 and RT 2 depend on the number of intermediate, anchor, corner anchors and other complex supports in the anchor span.
Rollers are attached to the supports in such a way that the axis of the SIP harness is at the level of the support clamp boat. This is done to reduce the force on the clamps when repositioning and to avoid improper adjustment of the clamps on the corner intermediate supports. Rollers for rolling-out RT 5, are fastened directly to the pillars of the supports using a fastening device with a belt. Rollers RT 5 are used mainly on anchor and other complex supports. Rollers RT 2 are fastened by the hole in the bracket of the intermediate suspension ES 1500E, thus significantly reducing the rolling-in time of the SIP. Rollers RT2 are used, mainly, on intermediate supports.
The set of the intermediate suspension ES 1500E from the company NILED, is designed for mechanical forces used during rolling.

Fig. 5.3. Set for rolling out the self-supporting insulating tape EdR70

5. The connection between the leader cable and the CIP
After the lead rope is rolled out, the connection between the SIP and the leader rope is made through the metal stocking CM1700, the metal stocking CM1750 for the carrier of the zero core of the SIP, the swivel E-B and the synthetic stocking CN covering the entire cord (Figure 5.3). In this case, one electroline clamp the stocking, increasing the diameter of the stocking, and the other - inserts the free end of the SIP into it. After release from the compressive force, the rolling stocking tightly surrounds the end of the CIP beam. For a more reliable connection of the stocking with veins, two bands of insulating tape are applied. To the cargo ring of the stocking the leader rope is attached and the reliability of the completed connection is checked. Information about the bundle for the rollout of SIP is insection .

6. Raskatka
Hand-rolled manually
Roll-off of a self-supporting conductor with a cross-section of a current-conducting core up to 50 mm2 can be carried out manually in limited areas of VLI (up to 100 m) and spans of up to 50 m. Mechanical rolling
After checking the readiness for the rollout of the SIP, a command is given to start the engine of the rolling mechanism. Responsibilities between the team members are distributed as follows: one electroline on the line regulates the operation of the petrol engine and monitors the uniformity of the winding of the leader cable onto the coil of the rolling mechanism, the other - monitors the smoothness of the rotation of the cylinder with the SIW; the others observe the passage of the leader-cable connection unit through the rollers. If necessary, the commands for stopping the rolling are transferred to the electrician located at the rolling mechanism.
The rolling process is continued until the entire leader cable is rolled onto the metal coil of the rolling mechanism, and the knot joining unit with the rolling stock does not come close to the coil. The petrol motor engine is stopped, the SIP is attached to the anchor support with a kapron rope or temporary anchor, after which the leader cable is loosened from the stocking and then the SIP is released. At the end of the rolling, when the SIP passed the last roller, it is necessary to leave the free end of the bundle long enough for electrical connection wires. For the purpose of unimpeded passage of the whole SIP through the rollers, especially at the first and at the corner supports, all technological operations should be carefully and carefully performed. In the process of rolling, SIP is not allowed to rub against the ground surface, metal and reinforced concrete elements of supports, buildings and structures. The rolling speed of the CNC should not exceed 5 km / h.

7. Tensioning and securing the SIP in the anchor span
In the process of tensioning and securing the SIP in the anchor span, the anchor clamp is fixed and fixed to the first anchor support, the tension of the SIP is secured to the second anchor support, and the SIP is secured to the intermediate supports. According to the mounting tables, depending on the ambient temperature, brand, SIP cross-section and arrangement of the supports in the anchorage, determine the amount of force with which the CIP carrier wire will be tensioned. It is allowed to pull the SIP with a force exceeding the projected value by no more than 5%, taking into account the elongation of the SIP in a few hours after the end of the installation due to the release of deformations that occurred during winding and storage on the drum.
Visually (according to sagging arrows), the quality of the tension of the SIP in the anchorage is evaluated, after which the wire, as a rule, leaves "hanging" before the next shift begins.
Adjustment of the sagging arrows is performed as follows:
- Install the anchor clamp RA 1500  on the supporting zero vein on the end (anchor) support. On the tourniquet in place of the anchor clamp, a plastic shrink band E 778 is applied to prevent unwinding of the tow.
- Suspend the clamp on the bracket of the end support CS 10.3.
- Simultaneously unwind the surplus SIP on the drum.
- Install the mounting clamp SCT 50-70 on the supporting zero vein as far as possible in the span, and attach to it a dynamometer and a manual winch PT 500, pre-mounted on the first support of the line.
- Tighten the self-winding winches of the PT 500, while the force is controlled with a dynamometer.
- Attach the clamp to the bracket and install it on the supporting zero core.
- Remove the manual winch PT 500.
- Use the clamp E 778 to connect the wires together.

8. Adjustment of self-supporting insulated wire
The force in the wire is measured by a dynamometer. Failure to comply with this requirement may lead to a violation of the SIP dimensions or the occurrence of unacceptable loads and impacts on the VLI supports.
Suspension of the self-supporting insulated wire is carried out with the help of fixing reinforcement, which is fixed only to the supporting zero vein (for the main SIP). In the calculations of the SIP suspension, the following climatic models of loads calculated according to the standards applied in Russia are taken into account:
1. Temperature + 40 ° C, wind and ice are absent.
2. Temperature -40 ° C, wind and ice are absent.
3. The wires are covered with ice, the temperature is -5 ° C, there is no wind.
4. High-speed wind pressure 26.5 daN / m2 temperature -5 ° C, ice is absent.
5. The wires are covered with ice, the temperature is -5 ° C, the wind speed is 6.65 daN / m2. Whatever the climatic conditions (high-speed wind, temperature, snow accumulation, ice-frost deposits), the force applied to the carrier zero vein CIP should not exceed 700 daN.
The traction at the suspension of the self-supporting insulated wire on the supports of 0.4 kV insulated overhead line is determined from the graphs (mounting tables) depending on the span length and design parameters.

Example of the work:
The adjustment is carried out on a 150 m long section of the VLI consisting of one, two or three spans of up to 50 m in length bounded by anchor-type supports. The tensioning device is attached to the top of the final support of the anchor type. To adjust the SIP and install the clamping jig on the carrier zero conductor, perform the following steps:
  pull the CIP to the required value of the tension measured by the dynamometer;
  mark the place of attachment on the supporting zero vein;
  establish an end clamp;
  install additional traction, which secures the clamp to the suspension;
  loosen and remove the tensioning device;
  Cut the wires, leaving the ends of the required length;
  remove the rolling roller.

Tensioning device installed on the ground
This device must be installed and retracted, increasing the tension of the SIP on the top of the end support, ensuring the installation of the clamping attachment on the supporting core of the SIP.

Override
After the CIP is rolled over the entire length of the FIR and the first anchorage is made, the SIP is supported by a pulling device mounted on the ground at the end of the FIR. Adjustment of the first section
The first section is adjusted by means of an anchorage. This operation requires the installation of a guide roller on the double bracket in parallel with the rolling roller.

Adjustment of the remaining sections of FIR
On the remaining sections of the VLI, the adjustment is carried out in the same way as described above. The last fastening is regulated similarly to the case with a single span. To adjust the SIP and install the clamping jig on the carrier zero conductor, perform the following steps:
1. act simultaneously with two tensioning devices (one at the end of the VLI, the other on the double bracket), simultaneously adjust the first span and the necessary "softness" of the fastening; | |