Now there is an active process of development and distribution of the network of overhead power lines, which has led to the creation of modern technologies using self-supporting insulated wires.
Most often, self-supporting insulated wire can be seen when installing external, power and lighting power supply lines. After the appearance of such a technologist, the technology of operation, repair and construction of power transmission lines has radically changed. The tracks that were made using self-supporting insulated wire have the conditional name "VLI".
To illuminate private houses, use self-supporting insulating wire, or self-supporting insulated wire.
The essence of the simple insulation is made of XLPE. This material is not subject to changes in temperature and humidity.
Installation of self-supporting insulated wire from the support to the building is possible in case of full compliance with the work schedule. Any installation work must be carried out by a suitable specialist.
Completely excludes the possibility of the cable snagging at strong gusts of wind.
The wire does not oxidize at the points of attachment and connection. The likelihood of emergency situations is minimal.
When installing, it is necessary to use a wire, according to the voltage in the network and the expected load. On the support, the self-supporting insulated wire is held by means of a banding hook. The hook is mounted on the post with a banding tape.
On the wall of the building, a different reinforcement is used, a wall hook with anchor bolts. It is necessary to make sure that the SIP is in good working order. The insulation resistance is measured with an ohmmeter, the health of the cores and the absence of a short circuit are measured with a multimeter.
In addition, each electrician must carry certain uniforms and equipment with him:
No type of work should be carried out when:
Ladders are very tricky. Therefore, their height should not exceed five meters, and the angle between the support and the ladder should not exceed 60-750.
But in any case, it is strictly forbidden to pull the wires while standing on the stairs.
If the wire breaks, the electrician will not fall.
At the stage all the necessary information about the VLI line is collected. The actual location of the route, the required number of supports, what type of support, all the technical parameters of the wire used, the specific technical features of the projected route and the performance of electrical work.
Directly, the installation of the self-supporting insulated wire is already started after the supports are installed and all the necessary specialized clamps are fixed.
To perform electrical work on the facades of industrial buildings and residential buildings, to make connections and the necessary branches, as well as to perform the necessary installation work, specialized fittings and installation tools have been developed. The project must necessarily contain all the necessary information about the materials, and contain a list of fittings for the installation of self-supporting insulated wire.
On all the supports of the anchor span, on which we mount the wire, we install specialized rolling rollers. On the extreme supports, the rollers are fixed with a special belt, on the intermediate supports, the rollers are fixed on the hook, in the lugs for the supporting clamps.
Behind one of the extreme supports of the span we install a drum on which the wire is wound.
We place it in a vertical position on a special stand that allows the drum to rotate during spinning. For a shallower angle of entry of the wire into the roller, install the drum from the support at a distance not less than its length.
On the opposite side, we install a drum on which the leader cable is wound, as a rule, it is a synthetic rope with a diameter of 10 to 12 mm.
The next step is manual rolling of the leader cable. We rise sequentially on each support, and fill the cable into the roller for further broaching.
After the leader cable is tucked into the roller on the last support, the cable is connected to the self-supporting insulated wire using a specialized stocking and a swivel, which does not allow the wire to twist during rolling.
This completes the preparation and begins rolling the wire.
The rope-leader is smoothly pulled in the opposite direction. The lead rope can be pulled manually or by a mechanism driven by an internal combustion engine.
During rolling, the wire follows the leader cable, rises on the support and enters the roller.
The drums and rollers are located so as to exclude the possibility of friction of the wire against the ground, support, etc. A technology is not allowed in which the wire is initially rolled along the ground, and only then rises to the support.
The rolling of the wire continues until the connection of the wire with the leading cable passes the rolling roller on the last support.
The next step is to attach the wire.
The carrier core or the entire bundle, depending on the type of wire used, is fixed in the anchor clamp, the ends are left of sufficient length for further installation.
And only after that we disconnect the SIP with the lead cable. The unrolling roller must be removed. Next, it is necessary to lead the cable into the lugs of the supporting clamps on all intermediate supports, and remove the mounting rollers.
The wire is tensioned using a hand winch on the first anchor support. The amount of wire tension can be indicated in the project or it can be taken from the assembly tables.
The tension must be strictly metered, you must have a dynamometer.
After the wire tension is over, the wire is fastened and tightened in the anchor clamp, and only then the winch and dynamometer can be removed.
SIP is used on reinforced concrete, metal, as well as wooden supports. can be used on the facade of the house. This wire cannot be used for laying routes underground.
On the support from which we plan to carry out the input, we mount a bracket to secure the anchor clamp. If the main line is made with non-insulated wire, then the bracket is installed below the traverse with insulators. When connected to VLI, the bracket is fixed below the line clamps.
On the support, the tap-off wire must be fixed in the anchor clamp, we leave the ends for connecting to the line. The connection is carried out by the workers servicing this line, after all the prescribed work has been completed.
At the point of connection, we use specialized clamps for bare wire, or piercing clamps if we connect to VLI.
On the facade of the house it is also necessary to install a bracket for attaching the anchor clamp. The wire, fixed in the anchor clamp, on the support, is inserted into the clamp on the facade of the house, pulled manually and fixed. As a rule, according to TU, the metering cabinet is located on the outer wall of the building, and the TU also provides that the input is carried out with a whole, visible piece of wire to the meter or the input machine located in the external metering cabinet, the installation of the self-supporting insulated wire goes along the facade of the building. We fasten the wires to the facade using specialized facade fasteners.
The meter itself is powered in the same way as as with traditional cable installation. We strip the wire from vinyl insulation if necessary, it all depends on the meter connection terminals, insert the stripped part of the wire into the terminal block, and carefully tighten the screws. It is safer and more convenient when the SIP is connected from the beginning to the input machine installed in front of the meter. The newest circuit breakers are equipped with bolt-on terminals, it is safer to use a cable lug.
If the meter is located inside the building, and the issued TU permits this option, the question arises - is it possible to bring the self-supporting insulated wire inside the room and make a direct connection or to entering the building and making the transition to another cable, for example, such as VVGng? Both options have the right to life, but we must not forget that the SIP shell is not fire-resistant enough when compared, for example, with the same VVGng, given this, it is not recommended to bring the wire into the room, especially if the structure is made of wood.
There is one more aspect, representatives of power supply will not accept the connection of wires located before the meter. There are two ways out of this situation.
We input whole pieces of self-supporting insulated wire, and during installation we use a metal pipe and a corrugated sleeve, pre-treated with a fire retardant agent.
On the facade of the building, immediately before entering the building, you can install a circuit breaker, connect the self-supporting insulated wire to the input terminal, and at the output there will be a cable that goes directly into the room to the meter. The switch itself must be placed in a small plastic box, and a seal must be placed.
The second option is more practical, since: material with a high degree of fire resistance is introduced into the building, and secondly, the section of the cable, in the place where it passes through the wall, is protected by a circuit breaker. In this case, an automatic input to the counter in the dashboard is not needed.
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