Cable pulling. Cable puller - a reliable device for laying a conductor in channels

My favorite broke (and happily found on the street!) fiberglass broach, which has been in many battles with holes, pipes and channels in the walls in the process of laying networks and even power cables. I was looking for a replacement for her for a very long time, and somehow I found one that more or less meets my nitpicking and requirements. I will try to express my thoughts on this topic in the form of a short review.

What is there anyway cable pull? This is usually a flexible, durable and indelible round structure, with the help of which soft and delicate cables are pulled into communication channels, boxes, corrugations and other similar things. The simplest application example broaches- these are Internet users who pull a twisted-pair cable from floor to floor: a low-current riser is usually clogged with other cables and wires, a twisted-pair cable is rather soft and it is very difficult (and sometimes impossible) to push it through this mess. And the rigid (and at the same time flexible) broach is perfectly pushed in and, due to its small diameter, passes through a bunch of cables perfectly. Then a twisted pair is tied to it and pulled.

In total, of those that I came across, there are three main types of broaches, classified according to the material from which its inner part is made:

• Fiberglass broaches. They have the greatest rigidity (and, apparently, the price too), and withstand all the tests of the form "you need to stick it into a small hole clogged with dirt and debris on the other side under a false ceiling." Cope with a bang in the most difficult situations. Also, due to the fiberglass structure, they tend to straighten up. This allows you to use it when laying cables in false ceilings such as Armstrong: the broach twitches and pushes - since it goes almost in a straight line, you can immediately push it five meters, open the plate and catch it there. And all this can be done by one person. Here () we just pulled the cables with such a broach. Minuses This broach is that fiberglass is a fragile material and if you bend it under a small radius, step on it, it will break. And now let's imagine: we tighten the twisted pair cable into the apartment, and there is almost an L-shaped turn. The cable does not climb ... let's pull harder - trrrrak! Minus stretch!
• Steel broaches. It feels like something in between (the price is also average - about 600-900 rubles per 10 meters) between fiberglass and some kind of minimum necessary for work. Steel broach consists of a steel tape or wire wrapped in a nylon sheath (nylon is a slippery material and this property is used in the manufacture of broaches). Due to steel, it turns out to be stronger than nylon in bending and stretching, but at the same time it has greater flexibility in the longitudinal direction, which probably will not allow it to be used as fiberglass when passing cables under ceilings. On the other hand, this flexibility will be useful when passing L-shaped turns in the channels.
• Nylon broaches. I really don't know why they release them. She has only one plus - the price (150-300 rubles). They are made of pure nylon and do not straighten at all - it can be useful for complete beginners who have problems with money. It can be used for pulling only in closed channels: boxes, pipes, and can be a metal hose, as it also has a flexible head. As soon as I bought it for myself, I was immediately upset, and it has been lying around idle since the summer.

Estiare steel broach (nylon coated)

So, here's what I bought. I bought it in the Shop220.Ru store, hitting it from a search. Description of the broach from the store -. While driving home, I looked at the packaging and was inspired by the description of possible additional accessories: here you have a device for gripping the broach itself (so as not to pull with your hands), and a special spring for quickly clamping cables and even gel lubricant (BDSM?! ;))! It's also cool that all these devices are simply screwed onto the main part of the broach.

So let's unpack the box. A bag with standard accessories is glued from the inside with adhesive tape, which caused my question to the sellers: “Is there anything in the kit at all?” - since nothing was shaking and dangling by ear while I was buying it (but the sellers, after the question of broach, greeted me with the question: “Oh! Do you connect the Internet, right?”) :) There are two accessories: a flexible head and a tail for attaching a pulled cable.

The broach itself is heavy and durable in appearance, worth the money and well done. I also liked the idea with interchangeable screw-on lugs: for example, using a flexible head, push two meters of this broach into a metal pipe, and then, unscrewing the flexible head, put on the tail, attach the cable and pull the entire structure back, instead of pulling everything out 10 meters (Yes, yes! These steel broaches start from 10 meters in length).

As for self-flattening, I was a little upset - it does not straighten as quickly and strongly as fiberglass, but at the same time it has enough flexibility for acceptable work. I immediately decided to test it in the “case”: I scattered it around the apartment - in the photo below it straightened itself like this, and pushed it into a relatively clogged channel from the apartment to the stairwell. A little effort - and the broach came out on the other side. On this, I recognized such synthetic tests as valid, collected it and postponed it until the first large order - there we'll see how it is in this work.

There are a huge number of different terms and verbal expressions inherent in a certain professional field of activity.

For example, all specialists involved in the construction of various electrical, telephone and intercom systems know what a cable pull is.

This is exactly the device that cannot be dispensed with when laying wires through various voids / pipes or switchboard cabinets. By the way, in another way this device is called an ultrasonic cable puller and its main purpose is to pull cables or wires into various communication channels.

At first glance, this design is very strong, flexible and unaffected by the external environment. In our today's article, we will try to reveal in more detail the topic of using cable pulling, as well as all existing types of this design.

Where is cable pulling used?

It should immediately be said that the scope of cable pulling is quite extensive. First of all, the design is used to create complex lines or systems in hard-to-reach places. This device helps to overcome various types of voids through which the cable is laid, such as: pipes, boxes, channels, metal hoses, floor panels.

The main function of ultrasonic testing is the introduction of the cable into the necessary environment for its full-fledged operation. Basically, broach is used in the following works:

• creation of an electrical wiring line;
• equipment for various types of communication, both telephone and computer;
• installation of intercom networks;
• formation of video, audio systems, as well as security systems;

It should be noted that the required temperature regime for the full operation of the product is -15C to +50C. The cable puller is able to last at least 1.5 years, but this indicator may vary depending on how aggressive the environment in which it is located and the intensity of use of the system. Of course, replacing wiring is a painstaking and time-consuming process, which is why pulling a cable allows you to do it much less often.

Types of cable broaches

Cable broach is classified according to the material of manufacture of its inner part, which protects the cable from an aggressive external environment. Thus, distinguish:

• fiberglass;
• steel;
• nylon.

Each type has its own characteristics and therefore is used in different situations. For example, fiberglass broaches have the greatest rigidity due to everything they practically cannot exist in a bent state and tend to straighten all the time. That is why you need to handle the material as carefully as possible, because due to bends, the material can be damaged. To a greater extent, fiberglass is suitable for pulling cables through small holes and stretch ceilings.

Steel broach is formed by metal wire or metal strip, which is packed in a nylon sheath. This material is responsible for providing better bending strength and preventing tensile deformation. This type of device is perfect for laying the cable cable through the L-shaped turns in the channels.

As for nylon cable broaches, they are great for laying cables through closed channels (pipes, various boxes). They have great flexibility and can coexist safely with other live cables.

As for cable broaches in general, it should be noted here that the device has recently undergone significant improvement.

The material from which it is made - polyester fiber, has a huge number of undeniable advantages, namely strength, wear resistance and quick adaptability to the environment. The latest cable puller has an exceptional property of preventing any friction. It is also absolutely resistant to ultraviolet radiation, all kinds of adverse weather conditions, to alkaline and acid solutions.

Cable broaches made of polyester fiber do not corrode over time and have good insulating properties. And thanks to easy color marking, they provide easy size identification and navigation in cable ducts, pipes,
tunnels.

That, in principle, is all the necessary information about cable broaches that you need to have. It is worth saying that this is far from all the information about this device, but it is sufficient to have an idea of ​​what cable pulling is, where it is used and what its practical purpose is.

If you want to understand this topic on a more professional level, then, of course, additional literature will not harm you. And we, in turn, wish you good luck and hope that the service life of this structure will not be 1.5 years, but will serve you for at least 10 years.

While laying cable indoors usually does not cause problems for installers, then laying cable between buildings by air is usually more labor intensive.

Between houses, communications can be laid in two main ways: underground and by air. Each of these methods has its pros and cons. This article describes how to lay the cable through the air. The advantages of this method include the simplicity of laying (compared to laying underground utilities), it is not always possible to lay underground communications, the length of the cable connecting the houses is much longer than in the case of an air connection. The disadvantages of laying through the air include the exposure of air communications to static electricity and lightning discharges, severe weather conditions that can lead to premature failure of the cable, in case of damage to the outer insulation of the cable due to friction of the cable in contact with other objects, or the occurrence of cracks due to weather conditions, the cable collects moisture and causes equipment failure (in this case, only cable replacement can help). Consider the connection of two houses by air. Hereinafter, we will agree to call such a connection an air connection.

Fig.1. Two houses connected by air.

In the figure: 1 - connected houses, 2 - cable, 3 - information cable (twisted pair). This is a rather rough outline of what should be the result. So, if you use a twisted-pair cable without a cable inside, then the use of a cable is simply necessary (wind, sticking wet snow, ice create huge loads, the twisted-pair cable is not designed for them). It is best to use steel wire with insulation as a cable. The cross section of such a cable with a reasonable length of air (less than 80 m) is enough 1 - 1.5 mm2. Insulation is necessary to exclude corrosion, which can literally “gnaw through” a steel cable of such a small cross section in just a year. It is necessary to fasten the cable on the house to something durable (iron fittings, masts of other cables, etc.). Here comes the next nuance. It is necessary to prevent the steel cable from touching the metal fittings on both houses at the same time. Houses have different potentials, and therefore current will flow through the cable, producing pickups on the twisted pair cable, and some other unpleasant consequences are possible. The cable must be grounded. The cable needs to be grounded. Maybe on one side. But this will not be the best option, a much better option would be to ground the cable from two sides, but you must either ground it through a container on one side (hard on the other), or break the carrier cable in the middle using a dielectric (for example, from a textolite plate).

Now about the twisted pair cable. In our latitudes, the cable, which is in the open air, gets into very difficult conditions. The cable stretched between the houses is in particularly difficult conditions. Therefore, I recommend using a twisted pair cable with special insulation for external laying for air. Ideally, if such a cable is filled with a compound (hydrophobe). The use of shielded cables, in my opinion, is impractical. The screen will not save you from the accumulation of static electricity in the cable, but at the same time, cables with a screen are much more expensive. In order to save the equipment connected to the air from discharges of static electricity and from thunderstorms, it is necessary to use special devices, the so-called lightning protection.

So let's get back to the airbox. The twisted pair cable must be attached to the cable in advance. As fasteners, you can use any non-conductive material that is not exposed to water and weather conditions. It is most advisable to use nylon screeds. With the help of nylon ties (or other devices), the twisted pair cable is attached to the cable, and it is recommended to fasten the cable and cable with ties every 50-70 cm. It is necessary to control that the cable sags a little, otherwise it turns out that the cable also holds the cable. But at the same time, it is necessary to reduce this sag to a minimum (in Fig. 1 there is a very large sag, made solely for the sake of clarity of the figure). It is necessary to tighten the ties strongly, excluding any slip of the cable relative to the cable, but at the same time it is necessary to avoid damage to the cable by very strong tightening of the fastener (it is necessary that the contact surface of the fastening element be flat and the width of the element be at least 5-7 mm).

So, now let's go directly to the sequence of actions when laying the cable:

1. First, purchase a cable, cable, fasteners (nylon ties, etc.). The length of the cable is not less than (b + l), where l is the length added, taking into account the sagging of the cable and fastening to the house (Fig. 2).

Fig.2. Schematic plan of the air.

2. Next, on the roof of house 1, we roll out the cable. We measure the length of the wire that will be required from point A to the equipment connected in this house (naturally, if the length of the cable does not tighten, it is better to give a margin) and mark point A on the cable. We find point A on the cable. (we measure the distance from the attachment point at home 1 to point A). We lay the cable next to the unfolded cable (point A of the cable to point A of the cable). We measure the distance (a + d) on the cable from point A of house 1 (d takes into account that, firstly, the cable will sag a little, and secondly, that points A of houses 1 and 2 are at some distance from the edge of the house). We make fastening of the cable to the cable throughout the obtained segment. People 1 and people 3 pull the cable (Fig. 3), people 2 make fasteners. Minimize sagging of the cable relative to the cable.

Fig.3. The technology of fastening the cable to the cable.

3. So, our air duct is almost ready for laying, part of the free cable that will be laid around house 2 is carefully twisted into a bay and attached to the cable with adhesive tape (this is done so that the cable does not interfere during laying).

Now the cable is ready. You can continue.

The last iteration of cable tension between two houses can be performed in two ways: 1. By pulling the cable through the ground and sequentially pulling it from the roof of house 1 guns), to which one end of the cable is tied on the roof. After that, the cable is pulled out by the shooter for the fishing line from the roof 2.

Detailed description of method 1.

We need two "buffer" cables (or rope, nylon thread, etc., the main thing is to withstand the weight of the cable and the carrier cable). We securely fasten one end of the cable to house 1, attach the second end of the cable to our buffer cable 1, and lower the buffer cable 1 down from house 1 (Fig. 4). Then we transfer the end of this cable to house 2 (we carefully go around trees and other high obstacles).

So, we reached house 2. From house 2, the end of the cable 2 descends. The ends of the cables are fastened and we begin to tighten the fastened cable to house 2. Pull, pull, pull, pull, pull the end of the cable with the coiled cable to house 2. We pull the cable, but not like a string, let it sag a little. We fix the cable at home 2, lay the cable, ground the cable.

A rare installation or construction team does without an ultrasonic device (cable laying device). This is an assembly tool used in the construction of electrical, telephone, computer, intercom and other systems. Cable broach (the everyday and more familiar name of the device) is essential when laying wires through boxes, voids, pipes, metal hoses, switchboard cabinets.

General description of the fixture

The broach (it is also an ultrasonic device, an arrow, a probe, a jig, a rod) was invented for pulling cables or wires into various communication channels. It looks like a strong, flexible, indelible design. Some types of devices are capable of self-straightening.

The broach has an internal cord. It is formed by a round rod. The compact core consists of unidirectional reinforcing fibers, radial threads that wrap around the longitudinal reinforcing fibers in a crosswise manner. This is the main part of the device - a bar. It is made from various materials.

The bar is covered with a special braid (sheath), which serves for ease of operation, increasing the service life of the device. A rod of great length is wound on a coil, placed on a cassette in a bay. The cassette is rotated, as a rule, manually. The bar is supplied with removable tips.

The normal operating temperature range of the product is -15°C to +50°C. The average service life is 1.5 years. But the safety of the rod depends on the intensity of use, the conditions of use.

Types of broaches

Cable pulling can be carried out using various types of devices. They are classified according to the material of manufacture of the inner part. There are such types of broaches:

• fiberglass;
• steel;
• nylon.

Fiberglass broaches have the greatest rigidity. Due to the structural features of fiberglass, they tend to straighten up. This allows you to pull the cable through small holes, suspended ceilings. However, the handling of such broaches requires care. Fiberglass is a fragile material, it is afraid of bending at small degrees.

A steel broach is formed by a metal wire or a tape packed in a nylon sheath. The steel material provides the best bending and tensile strength of the broach. This type of device is very effective for pulling cable through L-shaped turns in channels.

Closed channels (metal hoses, boxes, pipes, etc.) are good to go through with nylon broaches. The device has a guide of special flexibility. It can be combined with a pressed brass ferrule. Due to the dielectric properties of nylon, it is safe to pull near live cables.

Device package

Traditionally, ultrasonic testing consists of a set of tips, a glass rod, and a trolley. Richer configurations may include additional accessories. Manufacturers offer broach grippers, a special spring for quick cable clamping, and gel lubricants.

Depending on the length of the rod, it is folded into a circle or wound on a coil. More massive reels are mounted on a trolley, which has wheels for easy and quick movement.

Marking numbers indicate the diameter of the bar, its length. The diameter of the bar is measured in millimeters, it can be 3.5 mm, 6 mm, 9 mm, 11 mm. For example, the numbers 11/150 mean that a rod with a diameter of 11 mm and a length of 150 m is wound on a coil.

For the convenience of tightening the cable conductors, the rod is terminated on both sides with lugs. They serve for the convenience of gripping and tightening the wire. Thus, a double loop lug (cable stocking) is able to quickly and efficiently grab a cable weighing up to 5.5 tons and hold the conductor in a vertical plane for installation.

The tips are threaded, which allows you to attach various devices. These can be guide heads, connecting tubes, rotation compensators, etc. The most widespread are 2 types of tips: with a guide head and with an eye for attaching a pulled wire.

As an auxiliary, hydraulic cable jacks, cable guide rollers, protective cable glands, cable bends (elbows) can be used. Reduce traction, protect the conductor from mechanical damage, various lubricants - gels for lubricating the cable.

Where applicable

To create complex lines or systems in hard-to-reach places, installers and builders actively use the cable pulling device. The device helps to overcome various types of voids in the way of laying:

• pipes;
• boxes;
• channels;
• metal hose;
• cover panels.

Functionally, the use of ultrasound is comparable to the use of a probe. The tool is used to introduce cable and wire products into the desired work area.

The cable puller is used for:

• creating an electrical wiring line;
• telephone or computer communication equipment;
• installation of intercoms;
• formation of video and audio systems;
• equipping security and fire alarm systems;
• installation in suspended ceilings, under flooring.

Ultrasound is used when it is necessary to stretch a wire or cable inside a closed cavity. First, the channel is traversed with a bar. Then a cable (wire) is attached to a special nozzle. After fixing the cable, the rod is pulled back, pulling the cable through the interior of the channel.

Advantages of modern devices

The development of the latest technologies leads to the continuous improvement of ultrasonic testing tools. A modern cable puller is often made from polyesters (polyesters).

Initially, polyester fiber has a number of undeniable advantages. The material is durable, wear-resistant, slightly creased. Therefore, the use of innovative materials and technologies provide a number of advantages for modern ultrasonic testing.

The latest cable puller features exceptional anti-friction properties. The spiral shape greatly reduces the contact area.

High quality workmanship is guaranteed by imported raw materials supplied by leading European manufacturers. This results in a coefficient of friction that is reduced by 50% compared to nylon counterparts.

Mini UT, polyester wire puller stands out for its special flexibility and spring force. To these qualities are added a minimum bending radius, high tensile strength. Unlike fiberglass, polyester tooling does not break, it creates a heavy-duty connection according to the “pull-tip” principle.

Made of polyester, the cable pulling tool is resistant to UV radiation, various weather factors, alkaline and acid solutions. Devices made of this material are not subject to corrosion, have good dielectric properties. Color coding provides easy size identification and navigation in cable ducts, pipes, tunnels.

For various reasons, it is not always possible to lay an electric cable underground to the object that needs to be provided with electricity. In such cases, the technology of laying cables or individual wires through the air on a cable is successfully used. In the article, we will consider how the cable is installed and laid on a cable to the house, garage, what types of fastening are used.

Scope of technology

Such technologies are used only in power networks with a voltage not exceeding 1000 volts, the requirement of the PUE chapter 2.1. In most cases, stretching cables are used from buildings or power lines to individual structures over short distances. Where the installation of power transmission towers or digging cable trenches is not possible due to the technical conditions of production during the operation of facilities, or is unjustified in terms of the amount of work performed, it is expensive from a financial point of view.

In production workshops, warehouses, buildings with large areas, high ceilings, the best option for lighting is to use these technologies. Cable extensions are used for electric networks of street lighting of certain territories.

For owners of a private house, this wiring method allows you to get rid of the laborious work of digging a trench. It is easier to stretch the cable through the air from the switchboard in the house to the outbuildings:

• workshop;
• summer kitchen;
• gazebo with barbecue;
• chicken coop;
• bathhouse and other possible facilities in the yard of a private household.

Cable wiring allows you to run light three-wire wires for electrical consumers of low power and cables with wires of large cross-section for powering powerful household appliances. Before proceeding with the installation of cable wiring, preliminary calculations are required.

Preliminary measures before installation

At the first stage, it is necessary to determine how much power will be consumed by electrical appliances in the facilities that are planned to be provided with electricity. Based on the power consumption, the cross section of the cable wires is calculated, its length and weight are taken into account. These parameters determine which fasteners to use, the diameter and material of the cable. To calculate the power consumption and cable cross-section, a more detailed study of a separate topic is required. In simplified form, it looks like this:

• The power of all electrical appliances is summed up, which are supposed to be used in the calculated network. The power on each device is indicated in the passports for the products or nameplates on the case. The simplest example of a lighting lamp is always written 40 on them; 60; 75 or 100 or more watts.

∑Р = P1 + P2 +…Pn = 3.7 kW. (3700 W) - Total power.

• Determine the maximum possible current in the circuit

I \u003d ∑P / U \u003d 3700 W / 220 V \u003d 16.8 A. - Maximum current.

U is the mains voltage.

• To determine the cross section of wires in a cable, we use the table

In our case, we choose the value of the maximum current a little more than 19A, taking into account that additional household appliances can be used in the future. According to the table, we get a power of 4.1 kW, which corresponds to a copper wire cross section of 1.5 mm. It must be understood that the cross section is not a diameter, it is calculated by the formula:

Experienced electricians are well aware of the standards of cables, wires and determine the cross section by eye. For ordinary consumers, there are tables for determining the cross-section by diameter, it is enough to measure the diameter of the wire with a micrometer or caliper and determine its cross section from the table.

• The next stage of preliminary work, cable length measurement from the switchboard in the house to the switchgear (switchgear) on the building to which the cable structure is extended. This can be done with a regular tape measure,

Tip #1. Be sure to take into account the cable margin for cutting and connecting to the switchboard, add about 30 cm from both ends.

Choice of cable diameter and material

Determine the weight of the cable and other elements that will be attached to it. If the distance between the support mounts is 5-6 m and the weight of the wire is not significant, you can stretch galvanized steel wire with a diameter of 2-3 mm. When the distance is more than 10 m, the cable is heavy, especially if the cable structure is used with lighting elements, a galvanized steel cable with Ø 4-6.5 mm is used. Such a cable will withstand any cable with a wire cross section of up to 10 mm / sq., more is not used in private households, due to the limitation of power consumption. You can hang up to 5 pieces on such a cable. lighting lanterns in a lightweight housing.

The cable can be wound and weighed on conventional scales, or calculated, knowing its brand according to the characteristics table that is attached with the sale. The weight of the cable is indicated per 1 m, it is necessary to multiply the indicated weight by the number of meters to get the total weight of the segment, which is used for fastening on a steel cable.

For domestic conditions, in order not to spend money, you can hang the cable that was used for hidden wiring. In order for the insulation to last longer, lay it in a corrugated pipe, its weight is not significant. There are reference tables indicating the brand and weight of the cable. You can look it up on the Internet, some sites have calculators for calculating the length and mass of wires and cables.

Tip #2 Use the calculator on this site http://kabelves.ru/

For high current loads, it is better to use special cables for cable air structures:

• AWT, AVTS, APT already have a built-in load-bearing steel cable;
• AVRG, ANRG, APVG, AVVG are suspended from a supporting steel cable.

Support and tension elements of cable wiring

These products are installed on the walls of buildings, structures between which stretching is stretched. Depending on the material and diameter of the cable, the fastening design is selected:

• Tension bolt, with hook and tension anchor are used for flexible stranded cables of industrial production bearing heavy loads, rolled wire with a diameter of up to 6 mm can be used.
• Anchors for string tension with a small diameter are designed for light wires with a cross section of up to 6 mm at a distance of up to 10 meters, without lighting elements.
• Industrial cable anchors and wire rod anchors are able to withstand heavy cables and lighting elements at a distance of up to 12 m without additional supports.
• Fasteners for stretching parallel lines are often used for a dual purpose, for power supply of structures and for the placement of lighting lanterns. A power cable with a wire cross section of 10 -35 mm / sq. is laid along one cable, lighting fixtures, junction boxes with a copper wire of 2.5 - 4 mm are laid on the second.

All these structures have individual features when mounted on the walls of buildings.

Requirements for the installation of end fasteners and installation features

Never fasten the end elements to the decorative cladding of the building and roofing parts. Devices designed for heavy loads are fixed on both sides of the load-bearing wall with steel plates tightened with through bolts. As shown in the picture for the tension bolt with hook. They should be located above pedestrian walkways at a height of at least 2.7 m, and above traffic lanes at least 6 m. Anchors for strings with a lighter load can be fixed with simple anchor screws on concrete.

Ideally, tension anchors are embedded in the wall during the construction of the buildings according to the project. In practice, this is not always provided for, then you have to drill the walls with a puncher. A metal plate with a bolted contact is attached under the end mount for 20-30 cm to ground the cable. It is connected by a welding joint with a rolled wire with a cross section of at least 16 sq / mm, which goes to a common ground loop. In some cases, grounding is carried out with a separate copper wire with a cross section of at least 2.5 sq / mm bolted connections.

Installation and tension of the cable

After installing the terminal fixtures, on the ground the cable is attached to the extension, the lighting fixtures with junction boxes are fixed and connected. The assembled structure is delivered to the installation site and unrolled along the entire length from one fixing anchor to another.

The cable length must be at least 2 m longer than the distance between the end anchors. The stock will be needed to seal the mount on the terminal devices and bring the ends to the ground terminals, which are located below the anchors. The end loops of the cable are attached to the tension anchors, after which the tension is regulated by them. The stretching force should be for lightweight structures with cables with a cross section of 4-10 sq. / mm - up to 100 kg. / cm. For heavy cables with a cross section of 16 - 25 sq. / mm - up to 500 kg. / cm. This parameter is measured with a dynamometer, which is installed between the anchor and the brace loop.

After tensioning the cable, the ends of the cable are grounded, the cable is brought to the distribution devices and connected to the protective circuit breakers.

Elements for fastening the cable to the cable

To securely fix the cable with a cable, there are several devices:

The easiest method cable twisting with stretching with ordinary aluminum wireØ 2.5 - 5 mm with insulation. At the connections, after 50 -80 cm, 7-8 turns of wire are made, tight turn to turn. In order for the cable insulation not to be pressed through by the fastening wires, the fastening place is wrapped with a rubber plate, the wire is wound on top. It is recommended to use rubber for gaskets from old car wheel tubes;

The device is attached to the stretch, the cable is laid in the gutter, overlapped with a strap that is threaded into the lock, tightened and securely fixed. The lock is designed so that the strap cannot be pulled out in the opposite direction; to remove it, you can only cut it.

Plates with are produced with loops of different sizes. One plate is put on the cable, the other on the cable. In the center of the plates there is a hole with a thread for a bolt, they are combined and tightened with a bolt.

All connections, regardless of design, are installed after 50 - 80 cm.

Junction boxes and cable-mounted lighting fixtures

For fixing the junction boxes, special galvanized iron plates with cut-out shapes are used. A part of the plate is bent from the cut out form, a cable and a box are inserted, after which everything is fixed with folding elements.

Galvanized plates of a special shape are used to fasten lighting fixtures, but the principle of fastening remains the same, as shown in the figure.

• Cable;
• plate;
• Cable;
• Junction box;
• Plafond with lamp holder.

Frequently Asked Questions of Electricians

Question number 1. You can pull the cable, then attach the cable and other elements?

This can be done if the installation conditions on site allow it to be done without compromising safety when working at height. But after that, you will definitely have to increase the stretch, since the load on it will increase.

Question number 2. What wire should be used to connect the fasteners under the anchor to the ground loop?

Depending on your capabilities, rolled wire with a welded joint or copper, preferably with yellow-green insulation, as determined by the PUE. The cross section of the wires must be at least 2.5 kV/mm.

Question number 3. Can a cable be used as a neutral wire?

Yes, as long as it is properly grounded.

Question number 4. What kind of circuit breaker should be installed for a cable routed along a cable?

The design of the cable outlet in this case does not matter, the circuit breaker is installed based on the maximum load current in this circuit.

Question number 5. Can I hang junction boxes for outdoor wiring?