Low-voltage networks are an element of the engineering system of a building. In principle, almost any cable network can be called low-current if the cables are not supplied with power, but with information currents, the voltage of which is from 12 V to 24 V, and which vary exclusively in milliamperes.
Low Voltage Network Requirements
Among the basic requirements that modern low-voltage networks must meet today, it is worth highlighting:
- Extremely high reliability.
- Stable work without any possible failures or errors.
- Relatively low cost during installation and operation.
- Scalability.
Thanks to the possibility of using low-current systems, today it is possible to provide almost any type of communication, as well as ensure the normal functioning of computer networks. Depending on the purpose of a particular network, as well as where exactly it will be used, all of them are divided into commercial and domestic.
What are they needed for?
Using low-current networks, it is possible to carry out:
- Reception, as well as the subsequent distribution of both terrestrial and satellite television.
- Providing access to the telephone network.
- Normal operation and providing access to the global network.
- Design of wired broadcast networks.
- Normalization of the effective operation of security and fire systems.
- Normalization of the effective operation of warning and alarm systems.
- The use of access control systems for various objects (automatic control of barriers, gates and turnstiles.
- Fully automated metering system for managing various energy resources (water meters, electricity meters, home automated systems).
- The work of local area networks.
- Interaction between intercoms.
- Complete structuring of cable systems.
Mounting
Before the installation of low-voltage networks will be carried out, a full-fledged project of the future network is initially formed and, in particular, the future location of the shield, relays, sockets, as well as all other nodes that will be part of this system, is accurately determined. Engaged in laying all kinds of cables, installers perform all work in accordance with specialized rules, as well as approved standards.
What is included in the installation?
The installation of low-voltage networks in itself includes: laying telephone, computer or television lines, installing specialized information sockets, as well as other means of communication, installing intercoms, video surveillance, fire and security alarms and other equipment.
rules
At the same time, there are several important rules that must be followed when laying low-voltage networks:
- The minimum distance at which parallel laid power and low-current cables should be at least 0.5 m, and if they intersect, then in this case the angle of intersection should be 90 about . The distance between the laid lines of the Internet, as well as specialized power cables can be less than this distance, because during the transmission of digitized signals they are not affected by any interference.
- In no case should low-current cables run into a riser in which other electrical wires are placed.
- It is forbidden to spliced wires. Cable routing should be carried out exclusively using solid wire.
- In the event that the wires of the telephone network are laid in one direction, they must be laid in parallel and at the same time tightly pressed against each other.
- If the device of low-voltage networks and systems is not in hidden wiring, then in this case the minimum distance at which they are with the telephone network cables should be at least 15 mm if the line length is 10 m.
- The junction box should be located directly on the wall, but do not forget that it is strictly forbidden to place it above doors, windows or various openings. The minimum allowable distance at which the junction box should be located on the wall relative to the ceiling is 300 mm.
- Cables of different capacities that intersect with each other should be adjacent to the wall or should bend around it from above or below, depending on what capacity these cables have.
- Without fail, in the process of laying cables, it is necessary to provide for their protection. In particular, external low-current networks, which are installed under windows or drainpipes, require this, since they are most susceptible to various damages and for this reason involve the use of metal plates.
- Any low-current network lines must necessarily be grounded using a specialized bus, which is composed of carefully insulated copper conductors. Such conductors are used to connect a metal junction box directly to the ground line itself.
- If the project of low-voltage networks provides for the open installation of telephone network cables, then in this case they should be at a distance of at least 200 mm from the floor, and more than 150 mm from the ceiling. If we are talking about a closed method of laying, then in this case the cables can be at any height convenient for this.
- In the event that various digitized signals are transmitted along the network lines, then low-voltage electric networks can be located on the walls in the gates, specialized PVC hoses in the raised floor or floor screed, and can also be suspended from the raised ceiling.
Not sure how to do it? Trust the professionals
The design of low-voltage networks, as well as their subsequent installation should be carried out only by qualified specialists who have long experience in this field. Indeed, depending on the literacy and quality of all work, the quality of the signal, communication, and also how reliable and durable the operation of all equipment will directly depend. In addition, the quality of low-current work also affects the safety of equipment during its operation.
Telecommunication equipment
The use of telecommunication equipment is found in almost any case when low-voltage networks of various types of data are laid, and communication between several devices is also established. In this case, the quality of the equipment and materials used, which will be present during the construction of low-current networks, directly depends on how correctly all installation work will be carried out .
Telecommunication equipment includes two main elements.
Passive Network Equipment
- A set of patch cables that includes fiber optic cable and twisted pair.
- Connecting components, as well as a patch cord, designed to connect various devices to each other.
- Patch panels, including cross-panels for cable routing and direct fixation of cross blocks, as well as a patch panel for cabling in a rack and cabinet of signal wiring.
- Cable and panel connectors for signal transmission. The use of these elements is also found in patch panels, and depending on the number of contacts present, all types of such devices are divided into two-pin and three-pin.
- Information sockets equipped with modular connectors and designed to be installed in cable channels.
- Modular sockets, which are used to form cable networks, as well as the configuration of telecommunication outlets. These jacks are included in the modular panels and outlets. In order to connect active equipment, mortise contact technology through insulation is used, and depending on the cable used, sockets of various categories can be used.
Cable boxes
- A distribution cabinet, which is located directly inside the room and is used to connect wires to the mortise contacts of the skirtings, as well as provide cable termination.
- Instrument racks, which are used to place and integrate various devices of digital broadcasting systems.
- Cable boxes that are mounted at the points of transition to overhead communication lines. Such boxes are used as an effective protection of cable lines from various external influences or overvoltage.
- Distribution telephone boxes providing switching of connecting wires in communication systems.
What cables are used in such networks?
For full laying of a computer, television or telephone network, different types of cables are used.
If it is a question of laying low-voltage computer systems and networks, then copper cables of the “twisted pair” format from categories 5e and 6, belonging to class B and E, respectively, or specialized fiber-optic cables are used.
If you need to lay telephone networks, then in this situation it is quite enough to use standard low-current cables of the 3rd category. At the same time, when installing low-voltage networks, it is necessary to use electric cables through which data can be transmitted at a clock frequency of up to 1 MHz. The use of optical cables is most often found when it is necessary to lay backbone networks, since their use is determined by the need for an extremely high data transfer rate. The brand of cable is initially indicated in the installation diagram.
How are networks laid?
Depending on how the cable is placed, low-voltage networks can be laid:
- Underground . In this case, the cables are laid in specially designated underground utilities, which are also called cable ducts.
- Above the ground . Here, cables are transferred by air from one house to another or in those places in which wires are suspended on power lines.
- In a closed way . Cables are laid in specially designated trays in order to exclude the possibility of any damage to the network.
- In an open way . This type of installation is provided only if the network is completely unable to cause any damage.
In the process of choosing a cable, it is quite important to consider not only where it can be used and what technical characteristics it has, but also pay attention to ensure that the entire network meets the fire safety conditions.
conclusions
If you do not understand the field of cable wiring, then in this case you should not even try to carry out all the work completely independently. It is much better if all procedures, from the choice of cables to the subsequent installation of the entire system, including the maintenance of low-voltage networks, will be handled by qualified specialists who have been professionally working in this field for several years and know all the details of such work.