Requirements when choosing a fire alarm cable cross-section. Fire alarm cable: types of cable, GOST

Today, the role of fire alarms is appreciated. Until recently, it was installed only in special premises where flammable substances are stored or produced.

Now, offices, residential apartments and even private houses are equipped with such a system. To protect property and life, anyone can install a fire alarm. Specialists in this field have extensive experience in design and installation.

Design and calculation

At the design stage, the number of detectors, control panels, sirens, as well as the length of the cable route are calculated. Design is carried out based on the area of ​​the room and the category of the building. Piece positions, as a rule, are calculated accurately, but the length of the cables is taken with a margin.

According to the material consumption standards, 10% of the total volume cable products, it is necessary to budget for unforeseen expenses, such as bypassing architectural elements (columns, pilasters), changing the laying route, at the request of the customer, etc.

It is necessary to pay due attention to the selection of cables, because it is through them that an important alarm signal is transmitted. If you choose low-quality products, then loss of communication is inevitable. The operation of the alarm system is largely determined by the speed of signal transmission from sensors to sirens.

In a short time, information about a fire must travel a long way, notifying special services about the appearance of an open fire. In this case, cables play the role of “roads”. The worse the roads, the slower the signal moves. For correct operation of the system, cables must be selected in accordance with the design.

Required characteristics

According to Federal Law No. 123 dated July 22, 2008, cables and wires of anti-theft systems fire protection must remain operational in fire conditions, thereby ensuring timely and safe evacuation of people. Based on this, each cable has several important technical characteristics.

The first and, perhaps, main thing is fire resistance - the ability of a cable to transmit a signal when exposed to open fire. Simply put, the system must work even during a fire. Time complete combustion the cable must be sufficient to evacuate people. The fire resistance limit can reach three hours.

The second characteristic is the degree of flammability. Construction Materials They are divided into flammable, slow-burning and non-flammable. To find out which group the cable belongs to, you need to look at its designation. For fire alarms, cables with the designation “NG” are used, which means non-flammable.

The third parameter is toxicity. Quite a specific characteristic. It is indicated as a percentage and shows the level of toxic substances in the air when the cable burns. As a rule, they are laid in children's, educational or medical institutions.

Fire danger is the fourth indicator. The cable line of any system is connected to a current source, so a fire is possible inside the core itself. This occurs due to incorrect calculation of the cross-sectional area or poor quality cable.

Inspection and testing

Cable products are tested in specialized laboratories. At the time of testing, normal voltage is applied to the cable, as well as a flame from the burner (at least 700 ° C). If within 180 minutes there is no failure in signal transmission via the cable, then the test is passed.

When choosing the type of wiring, it is necessary to take into account the network voltage, moisture resistance and cross-sectional area. Cable products must meet the requirements of GOST R 53315-2009.

According to this regulatory document, cable products must have appropriate passports and certificates, and also be marked in accordance with technical characteristics.

Cable products are usually divided into categories according to the method of execution:

1. special performance. Laying such a cable is possible only after treatment with a fire retardant compound;
2. execution of "ng". For group laying in electrical installations open type;
3. execution type "ng-LS". For installation in closed electrical installations of industrial and residential buildings;
4. execution type "ng-HF". Possible installation in a bundle, in rooms where there will be at the same time a large number of people (concert halls, cinemas, offices);
5. execution type "ng-FRLS". Such power cables are laid in strategically important structures. Has the highest degree of fire resistance and explosion protection.

Cable line installation

Any of the above cables has a similar design. Inside are conductive copper wires, packed in insulation - a special type of silicone rubber, which provides fire resistance and protection from mechanical damage.

Several wires isolated from each other, collected in one bundle, are called twisting. The twist is packaged in aluminum foil called a screen. Its function is to protect current-carrying conductors from electromagnetic interference, which can cause false alarms.

A copper conductor is laid under the screen to ensure that the fire alarm operates without failure, even if the outer layers of the wiring are mechanically damaged. The outermost covering of the cable is called the sheath, which is usually made of PVC materials with a low fire hazard. The cross-sectional area of ​​the cable depends on the number of cores.

Cable installation is divided into single installation and group installation. When laying in groups, the distance between cables is no more than 300 mm.

In modern everyday life of the fire service, such a concept as system survivability has appeared. It refers to the ability of a system to function during a fire. According to international standards, the minimum time for evacuating people is 30 minutes. During this interval, the system must notify about the fire and adjust the movement of the crowd to avoid panic.

Fire alarms must not only detect, but also monitor the spread of fire, so cable products should not fail until the fire has been completely extinguished.

Wiring is supplied in coils, which indicate the manufacturer, brand, length, and weight of the cable. A label with a seal about the passage is attached to the bay technical control. When accepting the cable, you must pay attention to the tightness of the insulation and sheath.

During the operation of a fire alarm, it is necessary to carry out periodic checks of cable products for fire resistance, signal transmission, as well as mechanical damage shells.

What to look for?

To summarize, we can highlight the following parameters when choosing a cable:

1. category of the building in which the alarm will be located. Determined by the project based on regulatory documentation(GOST, SP);
2. manufacturer. Along with domestic manufacturers, imported specimens are also presented on the market. They tend to be more expensive;
3. cross-sectional area. The higher the voltage in the network, the larger the cross-sectional area should be;
4. fire resistance. Must correspond to the purpose and category of the building;
5. cable version. Depends on the specificity of the building and the number of people in it.

Recently, fire alarms have become a mandatory attribute of almost all facilities being built in Russia. Previously, only places where flammable substances were stored and/or produced were equipped with its elements.

In modern conditions, fire alarm systems are installed both in production and in office premises, apartments and even in private houses. Their widespread use is caused by the need to preserve human lives and property located in the fire zone in the event of a sudden fire.

IN general view any fire alarm system is a set of fire detectors connected to a control panel. At the same time, the reliability of its operation is largely determined by the quality and technical condition of the electrical wires connecting all the elements to each other.

A little history.

The first loops in fire alarm installations were mechanical. They were an ordinary rope on which a load was suspended. When a fire occurred, the rope burned out, the load fell and activated the signaling mechanism (bell, siren, etc.). It was this system that was first patented in the middle of the 19th century (England).

The system was subsequently improved (US patent, 1886) and various options design (a chain whose links were connected by fusible locks, etc.) was used until the advent of reliable electronic detectors connected using wire loops.

In the territory of the USSR, and then Russia, until 2009, when organizing fire alarms, electric wires of the KPSVEV and KPSVV types (in a red sheath) were used. In 2009, Federal Law No. 123 Federal Law dated July 22, 2008 was put into effect, stipulating all technical aspects fire safety at objects for various purposes.

Its provisions note that electrical wires used in the construction of fire safety systems must ensure the operation of the latter in case of fire for a period of time sufficient for the complete evacuation of people. In this regard, when organizing these systems, special fire-resistant wires, marked with a special index FR, must be used.

In order for the wires to match current legislation, differed from the cables used previously; they were made in a bright orange sheath.

TECHNICAL REQUIREMENTS FOR CABLE PRODUCTS

The uninterrupted operation of any fire safety system largely depends on the condition of the electrical wiring, which combines all its components into a single mechanism. After all, it is through the wires that a signal comes to the control panel, informing about the occurrence of a fire, and commands are sent to the actuators of the fire extinguishing systems.

Therefore, in addition to performing basic operational functions, cable products used in these systems must meet the strict requirements set out in GOST 315652012. Among these requirements, the most important are:

1. Fire resistance - the ability of wires to transmit a signal when exposed to open fire for a long time (about three hours). In this case, the burning of the wire should stop when the flame is removed. Non-flammable cables are marked with the index “NG”.

2. Minimum smoke generation, oxidation and toxicity. Such wires are also marked with the corresponding indices: LS low smoke generation, HF low oxidative activity, LTx minimal toxicity.

3. High degree of protection against electromagnetic interference, which is necessary when the system operates in industrial production. Noise immunity is ensured special screen made of aluminum foil.

4. High strength characteristics. If it is necessary to counteract external mechanical factors, an armored cable is used. Only cable products that fully possess the necessary parameters can be used when laying fire alarm lines both inside and outside buildings.

APPLICATION FEATURES

Cable products that are used for laying fire alarm communications have the same design and differ only in the cross-section of the wires and the materials used in the process of their manufacture.

The internal conductors are made of copper wire, which in some cases can be coated with tin. On the outside, they are protected by a sheath made of an organosilicon rubber mixture, which increases the strength and fire resistance of the cable.

In this case, several of these cores can be twisted together (twisted) and wrapped in aluminum foil, which will provide protection against false alarms caused by electromagnetic interference.

The entire cable structure is covered with a protective layer of special PVC materials or silicone rubber. These types of coatings are non-toxic and have low smoke emissions. In addition, they are able to withstand quite long exposure to open fire.

In cases where the cable needs to be given additional fire resistance, a winding on its outer surface is used:

• glass mica, which ensures the cable’s operability when heated to a temperature of +700°C for at least 3 hours;
• metallized magnesium insulation, allowing the cable to operate under open fire for at least 2.5 hours.

Nomenclature of fire wires and cables.

The domestic market for products intended for use in fire alarm systems offers potential consumers a wide selection of cable products. At the same time, the wire lines with the help of which all elements of the system are connected to each other can be divided into low-current and power.

Low-current types include cables of the following types:

• KPSE and KPS installation wires used in various configurations of fire alarm systems;
• KShSE and KShM cables used for laying signal cables and connecting fire detectors;
• KSB fire-resistant interface cable (twisted pair) for connection automatic systems;
• KSBG flexible fire-resistant wire for installation of alarm systems at industrial facilities, etc.

To connect equipment to power supply networks, power cables of the following types are used:

SHVVP used to connect to an alternating current network with a voltage of 220 V. It can be installed both indoors and outdoors. However, when used outside buildings, the cable must be placed in a corrugated metal conduit.

KUNRS installation fire-resistant wire for connecting devices operating under voltage 450...750 V AC or up to 1000 V DC. It is guaranteed to remain operational when exposed to open fire for 180 minutes.

INSTALLATION AND INSTALLATION

The laying of cable communications during the installation of fire alarms is carried out in accordance with the current regulatory documentation.

Wherein:

• only cable products with copper conductors are allowed to be used;
• It is recommended to lay cables with armored and heat-resistant windings in places where there is a high probability of fire;
• at air laying cables, it is necessary to use steel wire (cable) as the base of the suspension;
• When wiring, you need to take into account the possibility of cable shrinkage when high temperature;
• minimum diameter copper stranded conductor should not be less than 0.5 mm;
• low-current cables of fire alarm systems must be located at a distance of at least 0.5 m from power wiring;
• It is prohibited to connect cables and wires of fire alarm systems using the “cold twist” method.

When laying wire communications of fire alarm systems, the use of cable products that meet the requirements of GOST 315652012 will ensure reliable and maximum efficient work equipment in any, the most extreme conditions.

In turn, this will allow timely identification of the source of fire and prevent the spread of fire, while guaranteeing the safety of people nearby.

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On May 1, 2009, the Federal Law of the Russian Federation dated July 11, 2008 No. 123-FZ “Technical Regulations on Fire Safety Requirements” came into force, which defines the main provisions of technical regulation in the field of fire safety. Together with the Technical Regulations, a number of regulatory documents were prepared regulating the use of various types of cables in fire safety systems of facilities. One of them is GOST R 53315-2009 “Cable products. Fire Safety Requirements”, which introduced a classification of cable products according to indicators fire danger, the preferred areas of application of cable products are described, taking into account their type of execution, etc.

These cables are also used in systems security and fire alarm system(OPS), warning and evacuation control (SOUE), automatic fire extinguishing(AUPT), smoke protection and other life support systems, the maintenance of which is necessary in fire conditions for the time required for the complete evacuation of people to a safe area (fire resistance).

Such cables have the following design:

Current-carrying conductors are single-wire copper wire with a cross-section of 0.2-2.5 square meters. mm.

Insulation - fire-resistant ceramic-forming silicone rubber. When exposed to a flame, the organic component “burns out” and a coked layer remains on the conductive core, allowing the cable to perform its functions not only during a fire, but also after it, including under conditions of vibration and mechanical shock. It is the use of ceramic-forming silicone rubber insulation that provides fire resistance to the cable.

Stranding - insulated strands are twisted into pairs. There may be several pairs. The color combination of core insulation in pairs provides clear identification of each pair.

The screen is laminated aluminum foil. The function of the screen is protection against electromagnetic interference and false alarms. To connect to the equipment, a contact conductor made of tinned copper wire is laid under the screen, which, even if the foil breaks, allows the operation of the screen not to be disrupted. The cables may not have a screen (brands KnCHr(A)-FRLS, KnCHr(A)-FRHF).

The sheath is made of PVC plastic with reduced fire hazard with low smoke and gas emissions (ng-LS) or from a halogen-free cable composition (ng-HF). The main role of the sheath is to protect the cable from mechanical stress.

In addition to cables, for systems fire protection based on the same principle of fire resistance were developed power cables brand BPTHr(A)-FRLS with insulation made of ceramic-forming silicone rubber. These cables are designed for the transmission and distribution of electricity and signals in stationary installations at alternating voltages up to 660 V with a frequency of 50 Hz and keep the equipment operational for 180 minutes. in open fire conditions. These cables are used to supply electric shock medical equipment, ventilation and fire extinguishing systems, etc. The cross-section of current-carrying conductors is from 1.5 to 6.0 square meters. mm.

The main advantages (over traditional cables) of the VVGng-FRLS cable, which uses two-layer insulation in the form of a fire-resistant glass mica tape wound on a conductive core and a layer of PVC plastic on top of it, include ease of installation and cutting of the cable, its smaller dimensions, larger overload resistance and higher permissible continuous currents.

Thus, cables that remain operational in fire conditions are currently the main type of cable products that today can be used to build fire alarm systems and other automatic fire protection systems for objects.

Requirements for fire-resistant cable for security systems

First, let's define the concepts of cable fire resistance:

Fire resistance of cable (English (grade of) fire resistance) - the ability of a cable product to maintain operability when exposed to (and after exposure to) an open flame for a period of time established by standards and is determined by such parameters as fire resistance time (fire resistance limit), open flame temperature, operating voltage, cable laying conditions, etc. In the cable marking, this parameter is indicated by the index “FR”. (GOST R 53315-2009) The highest category in terms of fire resistance has the qualification designation PO 1, which corresponds to the standard time during which the cable must remain operational under conditions of exposure to flame, at least 180 minutes.

Cable fire resistance limit- the time determined from the beginning of the fire resistance test of the cable until one of the signs occurs in which it loses its functionality: short circuit, etc.

Testing the cable for fire resistance according to GOST R IEC 60331-23-2003

Fire resistance tests are carried out in accordance with GOST R IEC 60331-23-2003 and are as follows:
a flame is applied to a cable located horizontally gas burner(at least 750 °C).
At the same time, a normalized operating voltage (in in this case 300 V).
If no breakdown occurs during the entire test time (180 minutes), then the cable is considered to have passed the test.

Non-flammable cables - the term is absolutely incorrect. Often this term refers to fire-resistant cables, flame retardant cables (including flame retardant when laid alone), as well as flammable cables with “low-flammability” sheaths.

Flame retardant cables - cables that do not propagate fire when laid individually or in groups and spontaneously extinguish after the fire source is removed without providing additional protection. The main task of such a cable is not to become a way to spread a fire if it has already started. Non-propagation of fire by a cable characterizes the ability of a cable product not to burn in the absence of exposure to direct flame, and when exposed to direct flame, the combustion zone does not extend from the source of flame beyond the boundaries defined by regulatory documentation. In the cable marking, this parameter is indicated by the index “ng”. The designation ng(A), ng(B), ng(C), ng(D) determines the cable test category for non-propagation of fire in accordance with GOST R IEC 60332 (GOST R 53315-2009)

Testing the cable for flame retardation according to GOST R IEC 60332-3-22-2005

Propagation of fire during group installation (in the cable grade "ng" - non-flammable). This indicator characterizes the ability of the cable not to support combustion under conditions of exposure to flame. The highest category for this indicator is category A (in cable grade "A"), which shows that the cable has withstood testing under the most severe conditions for this parameter.

Tests are carried out in accordance with GOST R IEC 60332-3-22-2005: a cable bundle in sections of at least 3.5 m in length is placed vertically on a test ladder in the chamber. The total number of cable sections in the sample in a bundle is calculated so that the total nominal volume of non-metallic materials is 7 l (for category A) for 1 m of the length of the test sample. A gas burner flame is applied from the bottom of the beam for 40 minutes. (for category A). The sample is considered to have passed the test if the surface of the cable is damaged after burning and smoldering by no more than 2.5 m, measured from the bottom edge of the burner.

Fire resistant cables — cables that can remain operational in fire conditions for a certain period of time.

Single gasket- a single cable or a series of cables, the clear distance in air from which to the nearest cable exceeds 300 mm. (GOST R 53315-2009)

Group gasket- a series of cables with a clear air distance between them of no more than 300 mm. (GOST R 53315-2009)

Main indicators of fire safety of electrical cables

Index "LS"— smoke generation of cable products with the LS index when tested in accordance with GOST R IEC 61034-2 should not lead to a decrease in light transmission by more than 50%. (GOST R 53315-2009)

Halogen-free cable (index "HF")— cables with the “HF” index have a standardized low level of corrosion activity of smoke and gas emission products during combustion and smoldering of the polymer materials of the cable product. Smoke generation of cable products with the HF index when tested in accordance with GOST R IEC 61034-2 should not lead to a decrease in light transmission by more than 25%. (GOST R 53315-2009) Let us formulate the questions:

Since May 2009, a new federal law has come into force: Federal Law of the Russian Federation of July 22, 2008 N 123-FZ “Technical Regulations on Fire Safety Requirements”, which describes new requirements for fire safety systems of facilities. One of the significant differences from the previously existing regulatory framework is that in the Technical Regulations the operating time of all technical means of fire protection systems is calculated based on the time required for the complete evacuation of all people to a safe place. From this requirement follows the need to maximize the reliability and survivability of these means in conditions of the spread of dangerous fire factors in buildings and premises. Along with the law, some regulatory documents were prepared regulating the use of various types of cables in fire safety systems of objects.

Extract from the Federal Law of the Russian Federation dated July 22, 2008 N 123-FZ "Technical Regulations on Fire Safety Requirements"

Article 82. Fire safety requirements for electrical installations of buildings, structures and structures

2.Cables and wires of fire protection systems, means of supporting the activities of fire departments, fire detection systems, warning and management of evacuation of people in case of fire, emergency lighting on evacuation routes, emergency ventilation And smoke protection, automatic fire extinguishing, internal fire-fighting water supply, elevators for transporting fire departments in buildings, structures and structures in fire conditions within the time required for complete evacuation of people to a safe zone.

7. Horizontal and vertical channels for laying electrical cables and wires in buildings, structures and structures must be protected from the spread of fire. In places of passage cable channels, boxes, and wires through building structures with standardized fire resistance limit cable penetrations with a fire resistance limit not lower than the fire resistance limit of these structures must be provided.

8. Cables laid openly, must be flame retardant.

Article 103. Requirements for automatic fire alarm installations.

2. Communication lines between technical means automatic fire alarm installations must be made taking into account their functioning in case of fire during the time necessary to detect a fire, issue evacuation signals, during the time necessary to evacuate people, as well as the time necessary to control other technical means.

Article 84. Fire safety requirements for systems for warning people about fire and managing the evacuation of people in buildings, structures and structures

7. Systems for warning people about a fire and managing the evacuation of people must function for the time necessary to complete the evacuation of people from a building, structure, structure.

Article 143. Fire safety requirements for electrical equipment 4. Electrical equipment of fire protection systems must remain operational in fire conditions for the time necessary to completely evacuate people to a safe place.

Extract from the Code of Practice SP 5.13130.2009. Fire protection systems. Fire alarm and fire extinguishing installations are automatic. Design standards and rules:

13.15. Fire alarm loops. Connecting and supply lines of systemsfire automatics.

13.15.3. selection of electrical wires and cables, methods of laying them for organizing loops and connecting lines fire alarm must be carried out in accordance with the requirements of GOST R 53315, GOST R 53325, the requirements of this section and technical documentation for devices and equipment of the fire alarm system.

13.15.4. Fire alarm electrical wiring and connecting lines should be independent wires and cables with copper conductors. Electrical wire fire alarm loops should generally be carried out communication wires, if the technical documentation for fire control and control devices does not provide for the use of special types of wires or cables.

13.15.5. It is allowed to use dedicated communication lines in case of absence automatic control fire protection means.

13.15.7. , connected to various components fire automatic systems must be no less than the time it takes for these components to complete tasks for a specific installation location. fire resistance of wires and cables is ensured by the choice of their type, as well as methods of laying them.

13.15.8. in cases where The fire alarm system is not intended For driving automatic installations fire extinguishing systems, warning systems, smoke removal and other engineering systems fire safety of the facility, for connecting fire alarm loops radial type voltage up to 60 V to control and reception devices connecting lines made by telephone cables with copper conductors of the complex communication network of the facility can be used, subject to the allocation of communication channels. in this case, dedicated free pairs from the cross-connection to the distribution boxes used when installing fire alarm loops, as a rule, should be placed in groups within each distribution box and mark with red paint.

13.15.12. copper core diameter wires and cables must be determined based on the permissible voltage drop, but not less than 0.5 mm.

Excerpt from the set of rules sp sp 6.13130.2009 Fire protection systems. Electrical equipment. Fire safety requirements

Article 4. Fire safety requirements

4.1 cable lines of fire protection systems must be carried out fire resistant cables with copper conductors, flame retardant when laid in groups according to category a according to GOST R IEC 60332-3-22 with low smoke and gas emissions(ng-lsfr) or halogen-free (ng-hffr).

4.5. cable lines of fire protection systems must remain operational in fire conditions for the time necessary for the functioning of specific systems of the protected object.

4.6. cable lines of warning and evacuation control systems (SOE) and fire alarm systems involved in ensuring the evacuation of people in case of fire, must remain operational in fire conditions for the time necessary to completely evacuate people to a safe area.

4.15. time to maintain operability of cable lines and electrical panels are determined according to GOST R 53316.

Excerpt from GOST R 53315-2009. cable products. Fire safety requirements:

6. Preferred areas of application of cable products, taking into account their type of execution. The regulatory documentation for the cable product must indicate the scope of its application, taking into account fire hazard indicators and type of execution in accordance with Table. 2.

As can be seen from this table, for fire protection systems, cables with the indices - ng-frls, - ng-frhf are recommended, having a fire hazard class of at least p 1.1.2.2.2 for - ng-frls and p 1.1.1.2.1 for - ng-frhf.

According to this GOST, cables with such indices and fire hazard classes must meet the requirements of the following standards:
GOST R IEC 60331-23-2003 Testing of electrical and optical cables under flame conditions. Maintaining performance. Part 23. Testing and requirements for them. Electrical cables for data transmission.
GOST R IEC 60332-3-22-2005 Testing of electrical and optical cables under flame conditions. Part 3-22. Flame propagation along vertically located bundles of wires or cables. Category A.
GOST R IEC 60754-1-99 Testing of cable construction materials during combustion. Determination of the amount of halogen acid gases released.
GOST R IEC 60754-2-99 Testing of cable construction materials during combustion. Determination of the degree of acidity of emitted gases by measuring pH and specific conductivity.
GOST R IEC 61034-2-2005 Measurement of smoke density when burning cables under specified conditions. Part 2. Test method and requirements for it.

From the analysis of these standards, we conclude that, in addition to other requirements for non-propagation of flame, gas and smoke emission, toxicity, cables of fire protection systems (including fire protection systems) with open gasket must have a fire hazard class of at least PO1 (fire resistance limit in fire conditions - at least 180 min).

So, main criterion to select a cable for a fire alarm - matching it fire hazard class not lower than p1.1.2.2.2 for – ng-frls And not lower than p1.1.1.2.1 for - ng-frhf according to GOST R 53315-2009.

How to actually choose based on labeling and certificate?

For Russian fire-resistant cables: the most important thing is compliance with GOST 53315-2009. IN marking of cable products the type of execution must be indicated, i.e. the indices added to the brand must be indicated - ng-frls or -ng-frhf. IN fire certificate Compliance with the fire hazard class according to GOST R 53315-2009 must be indicated: clause 1.1.2.2.2 for - ng-frls and clause 1.1.1.2.1 for - ng-frhf.

It is allowed to indicate in the certificate compliance with the fire hazard indicator according to NPB 248-97: ppst 1 and ptpm 2 for – NG-frls and ppst 1, pka 1 and ptpm 2 for – NG-frhf, which does not contradict GOST R 53315-2009, but considered obsolete.

For imported fireproof cables: in marking:

the letter “H”, indicating the use of a halogen-free, anti-flammable polymer mixture in the insulation and shell, index E180, indicating a fire hazard class of at least 180 minutes.

Fire resistant cable marking system:

The fire certificate must indicate compliance with international standards:

IEC 60331-23 – for fire resistance.
IEC 60332-3-22 – for flame retardation.
IEC 60754-1 – for determining the amount of halogen acid gases released.
IEC 60754-2 – to determine the degree of acidity of gases released by measuring PH and specific conductivity.
IEC 61034-2 for the measurement of smoke density during fires of cables under specified conditions.

FRHF- Halogen Free, Flame Retardent - means: the cable sheath does not contain halogens and is fire resistant.
FRLS- Low Smoke, Flame Retardent - means: cable sheath with low smoke emission and fire resistant.

Conclusion:

Requirements for openly laid fire alarm lines: fire resistance, low smoke emission, no halogen emission, copper core diameter of at least 0.5 mm.

Requirements for openly laid SOUE cable:
fire resistance, low smoke emission, no halogen emission, the diameter of the copper core must be determined based on the permissible voltage drop.

Since the operability of the SOUE in fire conditions during the time required for the complete evacuation of people to a safe area can be ensured both by the properties of the cable and the method of its installation, then in fire safety systems we can use either fire-resistant cables ng-FRLS, ng-FRHF, or use a different type of cable using various ways protection (fire-resistant boxes, and even the cable can be hidden in concrete). The problem is that in the second case you will need to prove and calculate the performance of the system. This issue is quite complex, and not every designer can do this if he does not have a valid methodology and methods for testing the fire resistance of cable wiring.
The simplest way is to use fire-resistant ng-FRLS and ng-FRHF cables in fire protection systems without calculating their fire resistance, which is confirmed by a certificate.

Currently, the security systems market offers cables with a fire resistance rating of 180 minutes. Many people have a question: why so much? According to GOST R 53315-2009. Cable products. Fire safety requirements”, the fire resistance of cables is regulated by 30, 45,60,90,120,150 or 180 minutes. This gives the answer to those who are looking for cables with a fire resistance rating of 5-10 minutes (for a small facility - a shop, office, etc.). There are no such cables, since there are no such requirements - at least 30 minutes. Well, from a technological point of view, cables for fire protection systems are manufactured the same whether their fire resistance rating is 30 minutes or ISO, which is why most manufacturers declare the maximum value.

Modern manufacturers present fire-resistant cables of 3 types:

1. Cables with metal sheath and magnesium insulation. Cables in which one or more current-carrying cores are located in a metal sheath tube. The space between the conductors, between the conductors and the shell is filled with magnesium oxide ( simplest option- any heating element). Fire resistance of cables is achieved by the complete absence of combustible or thermally degradable structural elements cables, the destruction of which could lead to cable failure. When exposed to flame, smoke and toxic components are not released.

2. Cables with glass mica insulation. Cables in the design of which an electrical insulating and thermal barrier made of mica-containing glass tapes is used, wound over the conductive cores. Polymer insulation and a protective polymer sheath made of PVC plastics, reduced fire hazard (cable designation ng-FRLS) or halogen-free thermoplastic composition (ng-FRHF) are applied over the tape winding. The cables remain operational at a temperature of 750°C for 18O minutes. When exposed to flame, low smoke emission and low toxicity of combustion products are determined. The fire resistance of the cable is ensured by the fire-resistant properties of the insulation in the form of winding with glass mica tapes. Polymer insulation and sheath in these cables provide performance characteristics cable under long-term “normal” conditions and mechanical protection during installation and operation.

3. Cables with ceramic rubber insulation. The polymer sheath in such cables is made of PVC plastic compounds, reduced fire hazard (cable designation ng-FRLS) or halogen-free thermoplastic composition (ng-FRHF). The cables remain operational at a temperature of 750° C for 180 minutes. When exposed to flame, special ceramic-forming silicone rubber transforms into a protective ceramic layer (i.e., “ceramic” insulation), providing insulating properties in case of fire. The cables have low smoke emission. toxicity and corrosiveness of combustion products. IN normal conditions cable design provides high electrical characteristics, resistance to short circuit currents, resistance to prolonged exposure to elevated temperatures, resistance to bending, and in a number of designs, mobile operation of the cable under normal conditions.

Currently, cables with insulation made of ceramic-forming organosilicon rubber are being developed for single or group installation in buildings of preschool educational institutions, specialized homes for the elderly and disabled, hospitals, dormitory buildings of boarding educational institutions and children's institutions in the design ng-HFLTx and ng-LSLTx, those. cables with a toxicity index of combustion products of no more than 120 g/m3.

It should be noted that domestic manufacturers mainly offer cables made of silicone rubber for security systems, as cables that meet all the tasks assigned to them and are the most justified in cost.

Fireproof cable FRLS and FRHF: what is the difference?

Igor Neplohov, technical director of Center-SB LLC, Ph.D.

New regulatory requirements developed in accordance with Federal Law No. 123 “Technical Regulations on Fire Safety Requirements” determined the need to construct communication lines with fire-resistant cable to ensure the required operating time of systems in case of fire.

According to clause 4.1 of the set of rules SP 6.13130.2009 “Fire protection systems. Electrical equipment. Fire safety requirements": "cable lines of fire protection systems must be made of fire-resistant cables with copper conductors that do not propagate flames when laid in groups according to category A according to GOST R IEC 60332-3-22 with low smoke and gas emissions (ng-LSFR) or not containing halogens (ng-HFFR)".

The preferred areas of application of cable products, taking into account their type of execution, are defined in GOST R 53315-2009 and GOST R 53769-2010.

Preferred area of ​​application

In the absence of additional information, designers often choose ng(A)-FRLS cable, while most facilities should use ng(A)-FRHF cable.

The LS index, which is short for Low Smoke, is obviously more understandable compared to the HF index - Halogen Free. Perhaps this is the main reason for more wide application cable with LS index compared to cable with HF index.

According to GOST R 53315-2009 with amendment No. 1 “Cable products. Fire safety requirements”, a cable with the LS index is used “for laying, taking into account the volume of flammable load of cables, in internal electrical installations, as well as in buildings, structures and closed cable structures,” while a cable with the HF index is “for laying, with taking into account the volume of flammable load of cables, in internal electrical installations, as well as in buildings and structures with large numbers of people, including multifunctional high-rise buildings and building complexes.”

According to GOST R 53769-2010 “Power cables with plastic insulation for a rated voltage of 0.66; 1 and 3 kV. General technical conditions" the preferred areas of application of cables with insulation made of polymer compositions that do not contain halogens and with an outer sheath made of polymer compositions that do not contain halogens: "for cable power lines for electrical equipment of nuclear power plants (NPPs), electrical wiring in office premises equipped with computer equipment and microprocessor technology, in kindergartens, schools, hospitals and for cable lines of entertainment complexes and sports facilities.”

Cable fire hazard class

According to GOST R 53315-2009 in the fire hazard class designation:

the first indicator is the fire propagation limit (O1 or O2 for a cable product tested individually, or P1-P4 for a cable product tested during group installation);
the second is the fire resistance limit;
the third is an indicator of corrosion activity;
fourth - toxicity indicator;
the fifth is the smoke generation indicator.

Cable with fire resistance of at least 180 min. type ng(A)-FRLS has fire hazard class P1b.1.2.2.2, and cable type ng(A)-FRHF has fire hazard class P1b.1.1.2.1. Accordingly, the use of ng(A)-FRHF cable ensures not only a minimum emission of corrosive gases, but also significantly lower smoke emission compared to ng(A)-FRLS cable. Thus, for complete clarity, the ng(A)-FRHF cable should be called fire-resistant, halogen-free and smokeless, flame retardant when installed in groups.

Halogens, corrosivity and toxicity

In case of fire, a cable with the LS index emits halogens, which include chlorine and fluorine - toxic substances and energetic oxidizing agents that cause corrosion, which significantly narrows the scope of application of this cable. During a fire, the highly toxic hydrogen chloride gas released spreads throughout the facility and, when combined with water vapor, condenses on the equipment in the form of concentrated hydrochloric acid.

The permissible values ​​​​of the corrosiveness of smoke and gas emission products during combustion and smoldering of insulation materials, sheath and protective hose of cables with the LS index and the HF index differ by 28 times according to GOST R 53769-2010! The amount of emitted gases of halogen acids in terms of HCl for polyvinyl chloride plastic compound of reduced fire hazard of cables of the ng-LS and ng-FRLS versions should be no more than 140 mg/g, and for a polymer composition that does not contain halogens of ng-HF cables and ng-FRHF, no more than 5 mg/g.

In GOST R 53315-2009 there are no quantitative restrictions on the content of halogen acid gases in the requirements for cables with the LS index. For halogen-free cables with the HF index, GOST R 53315-2009 with amendment No. 1, in addition to the amount of gases emitted - in terms of HCl no more than 5 mg/g, the requirements for the conductivity of an aqueous solution with adsorbed smoke gas products of no more than 10.0 μS/g are given. mm and a pH value of at least 4.3. The same values ​​are given as recommended when assessing test results in accordance with GOST R IEC 60754-2-99.

Moreover, foreign fire halogen-free fire-resistant cables provide significantly more low performance corrosive activity compared to permissible values. For example, for FireKab FRHF, according to test results, the conductivity of an aqueous solution with adsorbed products was 4.8 μS/mm (allowed 10.0 μS/mm) and, accordingly, an almost neutral acid number pH = 6.2 (allowed pH no less than 4.3) .

Indicator of toxicity of combustion products

Toxic combustion products are the most significant fire hazard, especially in residential and public buildings. Toxic combustion products in our country include carbon dioxide CO 2, carbon monoxide CO, hydrogen chloride HC 1.

Tests are carried out in accordance with GOST 12.1.044-89: a sample of the smoldering material from which the cable is made is placed for 30 minutes in a sealed chamber with experimental animals (mice). The sample is considered to have passed the test if the gaseous combustion products caused the death of no more than 50% of the experimental animals. According to this indicator, cables of the ng-frls and ng-frhf types are classified as moderately dangerous (T2).

Determination of the degree of acidity of released gases

The degree of acidity of gases released during combustion of cable compounds is determined according to GOST R IEC 60754-2-99 “Testing of cable construction materials during combustion. Determination of the degree of acidity of emitted gases by measuring pH and specific conductivity.”

Samples of material with a total mass of (1000 ± 5) mg are burned in a sealed tube furnace at a temperature of at least 900 °C for 30 minutes. with a constant supply of air, the resulting gas-air mixture passes through one or two washing vessels with distilled water with a total volume of 1000 cubic meters. cm (Fig. 2). The pH value of the water should be 5-7, and the specific conductivity should be no more than 1.0 µS/mm. IN bottom part A magnetic stirrer is placed in the vessel to ensure turbulent movement of water and better absorption of released gases. After completion of the tests, before determining the pH value and specific conductivity, the volume of liquid is adjusted to 1000 cm 3 .

Emission of smoke during combustion and smoldering

According to the requirements of the technical regulations, the use of cables made of materials other than ng-LS and ng-HF (in the cable brand LS - Low Smoke) is not allowed in rooms where people are present. This is due to the fact that during a fire, a burning cable emits smoke and toxic substances dangerous to human health and life. As a rule, people die in a fire from smoke (combustion products), and not from the fire itself. Therefore, the cable product must be made of materials that provide good visibility in the area of ​​fire, which helps to carry out the fastest evacuation of people, as well as minimizing the number of victims during a fire from poisoning by combustion products. Tests are carried out in accordance with GOST R IEC 60332-3-22-2005: several pieces of cable are placed horizontally in a sealed chamber, under which a tray with alcohol is placed. The alcohol is set on fire and a decrease in light transmission is recorded in the chamber (a decrease in signal power in the photometric system). According to standards, the reduction in light transmission should be no more than 50%.

Rice. 1. Principle of cable smoke test

In fact, LS type cable is quite smoky - when it burns, GOST R 53315-2009 allows for a reduction in light transmission of up to 50%, which significantly limits visibility.

For cable type HF, GOST R 53315-2009 allowed a reduction in light transmission by a maximum of 25%, and in change No. 1 this value was increased to 40%, which corresponds to the recommendations of the international GOST R IEC 61034-2A, which is used to measure the density of smoke during combustion cables

Halogen-free FRHF is virtually smokeless. For example, FireKab FRHF cable, when tested to similar BS EN 61034-1-2/IEC61034-1-2 standards, showed a reduction in light transmittance of only 4%. In comparison, in similar tests, the ng-LS cable causes an 8 times greater reduction in light transmittance, approximately 30%, which significantly limits visibility, and the ng-type cable produces an even greater reduction in light transmittance, up to approximately 85%, which means a complete loss of visibility.

Fireproof choice

When choosing between an ng-FRLS cable and an ng-FRHF cable, it is necessary to take into account that the halogen-free ng-FRHF cable not only provides minimum values ​​for the corrosiveness of smoke and gas emission products during combustion and smoldering of the insulation, but also has several times lower levels of smoke generation in terms of compared to a similar NG-FRLS cable.

Such advantages of the halogen-free ng-FRHF cable determine the need for its use in buildings and structures with large numbers of people, including multifunctional buildings-complexes and high-rise buildings, as well as in office premises equipped with computer and microprocessor equipment, in kindergartens, schools, hospitals, entertainment complexes and sports facilities.

In conclusion, it should be noted that currently in Europe the LS type cable is not produced due to its high corrosiveness and significant smoke emission during a fire, but a much less fire-hazardous halogen-free smokeless fire-resistant NG-FRHF cable is produced and used.

Continuity index electrical connection shows how long the cable retains its insulation in the event of a short circuit or break in a fire. The electrical continuity rating is designated by the abbreviation FE (for example, FE180 corresponds to the duration of an unbroken connection under the influence of fire for 180 minutes). The continuity of the cable system depends on how long the electrical energy supply is maintained in the event of a fire. National regulations in most countries have specific requirements for emergency systems. Cables must meet these requirements.

Emergency evacuation

In many countries, a 30-minute interval is provided for the evacuation of people from a building in case of fire. In accordance with this requirement, emergency systems (fire alarm systems, emergency lighting, lifts, smoke removal systems, emergency voice and sound alarm systems, escape route indication systems) must use cables that comply with the E30 classification for cable systems. In buildings special design, such as high-rise buildings, hospitals, tunnels, penitentiary institutions, E60 or even E90 cables should be used, corresponding to a 60 or 90 minute duration that ensures the continuity of the electrical network (for example, to provide elevators for inpatients, etc. )

Fighting fire

In addition to the need to ensure power supply while people are evacuating buildings, additional time is needed for fire brigades to work. Generally, once a fire starts, it takes about 90 minutes to extinguish it. Systems for uninterrupted power supply to fire extinguishing systems (such as sprinkler pumps, mechanical smoke removal systems, fire elevators) must be equipped with E90 class cables (when exposed and unprotected).

Survivability during a fire

System survivability is a parameter that characterizes the ability of a fire alarm system to function during the development of a fire for the entire period of time required to evacuate people from the building. If previously the tasks of fire alarm systems included only detecting the primary source of fire, today the standards and approaches to the construction of fire alarm systems have changed. In Fig. 1-4 shows a comparison of several of the most common structures for constructing fire alarm systems, taking into account, first of all, their reliability and survivability.

The experience of Russian and European specialists shows that for the entire time required to evacuate people from buildings and premises, it is necessary to ensure the operability of the following systems:

* fire alarm systems;
* fire extinguishing installations;
* fire warning systems;
* ventilation and air conditioning systems, emergency ventilation, fire water supply control;
* elevator control systems.

Parts of a building in which a fire may occur usually cannot be determined in advance. At the design stage, the exact route of the cables may also be unknown.
As an example, let us analyze the duration of evacuation of people from a small rural clinic and from a regional hospital. In the first case, the process takes 5 minutes, while in the second it may take tens of minutes. However, during this period of time, most of the conventional fire alarm wires may fail, and uncontrolled spread of smoke and secondary fires will begin. At the same time, due to the lack of information about the dynamics of the fire, it is not possible to promptly manage the evacuation of people from the premises of a building that has caught fire.

However, even the use of fire-resistant cables does not guarantee the transmission of fire messages, especially in the case of partial collapse of building structures during a fire. The only way to solve the problem of constantly monitoring the spread of fire is to use multi-connected systems that have backup routes for delivering fire alarm messages.

The simplest example of the application of the principle of multiconnectivity in security and fire alarm systems is the use of ring communication lines (Fig. 3). Each device in the ring has a multiconnectivity coefficient of two, i.e. there is one main message delivery route and one backup route. More reliable and resilient are wireless systems that use dynamic routing algorithms, when each node of the system, in the event of damage to the main communication channel, can choose from a dozen backup routes (Fig. 4). Of course, some of the equipment may fail as the fire progresses, but that part of the premises where there is no open fire will be under constant control, which will make it possible to monitor the dynamics of the fire and make adequate management decisions.
Based on the above, we can talk about a significant increase in the survivability level of wireless fire alarm systems in cases of fires and emergencies.

The Ministry of Emergency Situations, together with the Russian Union of Rescuers, has issued technical recommendations for remote monitoring systems for fire protection installations, fire detection systems, warning systems and management of evacuation of people at facilities with large numbers of people. Technical requirements are recommended for work by design organizations designing fire detection, warning and evacuation systems in case of fire and fire automatics on objects.

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How can you save the cost of a fire-resistant cabling system?

Alexey Omelyanchuk. Beginning KB Rubicon LLC "SIGMA-IS"

Due to the fact that the current normative base clearly requires that the cables used remain operational throughout the entire evacuation period; all cables and wires must have the FR (fire resistant) index, confirmed by the appropriate certificate, and be secured with non-flammable materials (this also applies to dowels, which many people forget). Let's leave aside the issue of fire resistance for now; the practice of applying standards will clarify the actual requirements, and there will probably be many amendments to the regulatory documents. Let's discuss what types of cables are used in fire systems. And in the spirit of today, we will discuss what opportunities there are to save on cable products.

The main cables are cables for connecting detectors (sensors). If there is an alert of 3 or more types, also the alert connection cables. These are the main kilometers and kilometers of cables, and therefore they are often the main cost of the system. The cost of cables depends on the amount of copper in them, i.e. on the cross-section, however, for FRHF cables the price is now often determined by their shortage and is many times higher than similar cables in a conventional design. But this is probably a temporary phenomenon. For the foreseeable future, non-flammable cables will, of course, remain more expensive than conventional ones, but their price will also mainly depend on the amount of copper.

Addressable systems usually allow some savings on detectors, but little on cable length. Worse than that, addressable systems often require the use of much thicker wires or even shielded twisted pairs with normalized characteristic impedance, and this eliminates all savings. Many modern addressable systems are less cable-critical, and for them, as for conventional non-addressable systems, practically the only limitation is current consumption. Good modern detectors consume no more than 200 microns (and some less than 100), so even when installing several hundred detectors on one loop, it is acceptable to use very thin, cheap cables.

As for the warning cables, in the case of notification of type 1-2, addressable systems can provide some savings when using addressable sounders (otherwise you will have to separate the sounder wires separately). Unfortunately, most addressable systems do not provide the ability to connect sufficiently powerful sirens to the address line or require increasing the cable cross-section of the entire line, so no savings are achieved. Significant savings can only be achieved by using sounders (or voice amplifiers) with local redundant power supplies. In this case, the power cables do not have to be fire-resistant and can, roughly speaking, come from the nearest outlet, and control signals can easily be transmitted via an addressable loop without increasing the cost of its cable.

A separate category of cables is communication cables. Popular in Lately Ethernet-based systems are very convenient - new buildings always have SCS installed with a large margin. For classic systems based on the RS-485 interface, if the data transfer rate is 9600–19200 and the cable length does not exceed 100–200 m, you can use any cable (not just a specialized twisted pair). If you need to connect system components located at a large distance, you will have to use fiber optic cables (they are quite available in fire-resistant versions).

Finally, power cables. The requirement for fire resistance here also leads to the need to revise old stereotypes. If the previously popular solution was to install one central unit uninterruptible power supply and distribute independent 220 V power from it to all components, now it often turns out to be more economical to install distributed uninterruptible power supplies. However, for some systems, for example, for fire extinguishing pumps or smoke removal fans, it is necessary to carry out power laying with a fire-resistant cable, not only from the control controller to the fan itself, but also from the input into the building to the control controller. Such cables are quite affordable, but the range of domestic fire-resistant cables is not yet very wide; it may turn out that for large buildings and powerful loads it will be necessary to use imported cables.

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To be continued…

12.57. The selection of wires and cables, methods of laying them for organizing fire alarm loops and connecting lines must be made in accordance with requirements of the PUE, SNiP 3.05.06-85, VSN 116-87, the requirements of this section and technical documentation for devices and equipment of the fire alarm system.

12.58. Fire alarm loops must be designed to ensure automatic monitoring of their integrity along their entire length.

12.59. Fire alarm loops should be made with independent wires and cables with copper conductors.

Fire alarm loops, as a rule, should be made with communication wires, if the technical documentation for fire alarm control devices does not provide for the use of special types of wires or cables.

12.60. Fire alarm loops of the radial type, as a rule, should be connected to fire alarm control panels using junction boxes and cross-connections.

In cases where the fire alarm system is not intended to control automatic fire extinguishing installations, warning systems, smoke removal and other fire safety engineering systems of the facility, connecting lines made by telephone lines can be used to connect radial type fire alarm loops with voltage up to 60 V to reception and control devices. cables with copper conductors of the complex communication network of the facility, subject to the allocation of communication channels. In this case, the allocated free pairs from the cross-connection to the distribution boxes used in the installation of fire alarm loops, as a rule, should be placed in groups within each distribution box and marked with red paint.

In other cases, connecting lines for connecting radial-type fire alarm loops to fire alarm control panels should be made according to clause 12.58.

12.61. Connecting lines made with telephone and control cables must have a reserve supply of cable cores and junction box terminals of at least 10%.

12.62. When installing a fire alarm system with fire alarm control and control devices with an information capacity of up to 20 loops, it is allowed to connect radial type fire alarm loops directly to the fire alarm control and control devices.

12.63. Fire alarm loops ring type should be carried out using independent wires and communication cables, with the beginning and end ring loop must be connected to the appropriate terminals of the fire control panel.

12.64. The diameter of the copper cores of wires and cables must be determined based on the permissible voltage drop, but not less than 0.5 mm.

12.65. Power supply lines for control panels and fire control devices, as well as connecting control lines for automatic fire extinguishing, smoke removal or warning installations should be made with separate wires and cables. It is not allowed to lay them in transit through explosive and fire hazardous premises (areas). In justified cases, it is allowed to lay these lines through fire hazardous rooms (zones) in the voids of building structures of class KO or fire-resistant wires and cables or cables and wires laid in steel pipes according to GOST 3262.

12.66. It is not allowed to combine fire alarm loops and connecting lines, control lines for automatic fire extinguishing and warning systems with voltages up to 60 V with lines with voltages of 110 V or more in one box, pipe, harness, or closed channel. building structure or on one tray.

The joint laying of these lines is allowed in different compartments of boxes and trays that have solid longitudinal partitions with a fire resistance limit of 0.25 hours made of non-combustible material.

12.67. In case of parallel open installation, the distance from fire alarm wires and cables with voltage up to 60 V to power and lighting cables must be at least 0.5 m.

It is allowed to lay the specified wires and cables at a distance of less than 0.5 m from power and lighting cables, provided they are shielded from electromagnetic interference.

It is allowed to reduce the distance to 0.25 m from wires and cables of fire alarm loops and connecting lines without interference protection to single lighting wires and control cables.

12.68. In rooms where electromagnetic fields and interference exceed the level established by GOST 23511, fire alarm loops and connecting lines must be protected from interference.

12.69. If it is necessary to protect fire alarm loops and connecting lines from electromagnetic interference, shielded or unshielded wires and cables laid in metal pipes, boxes, etc. In this case, the shielding elements must be grounded.

12.70. External electrical wiring for fire alarm systems should generally be laid in the ground or in a sewer.

If it is impossible to lay them in the specified way, it is allowed to lay them on the outer walls of buildings and structures, under canopies, on cables or on supports between buildings outside streets and roads in accordance with the requirements of the PUE.

12.71. The main and backup cable power supply lines of fire alarm systems should be laid along different routes, eliminating the possibility of their simultaneous failure during a fire at the controlled facility. The laying of such lines, as a rule, should be carried out through different cable structures.

Parallel laying of these lines along the walls of premises is allowed with a clear distance between them of at least 1 m.

The joint laying of the specified cable lines is allowed, provided that at least one of them is laid in a box (pipe) made of non-combustible materials with a fire resistance limit of 0.75 hours.

12.72. It is advisable to divide fire alarm loops into sections using junction boxes.

At the end of the loop, it is recommended to provide a device that provides visual control of its on state (for example, a device with a flashing signal other than red with a flashing frequency of 0.1-0.3 Hz), as well as a junction box or other switching device for connecting equipment to assess the condition of the fire alarm system, which must be installed at an accessible location and height.

The principle of operation of fire and security alarm systems is to monitor attempts of unauthorized entry by unauthorized persons or the appearance of fire points with subsequent transmission of a signal to control and warning units. The connection of the main components (control panel, control panel, sensors, power supply, etc.) is provided by wires and cables for security and fire alarms. The products contain a copper core made of one or several wires; the insulating coating can be made of PVC plastic (security systems) or plastic compound (fire protection systems). Some types have an aluminum foil screen located under the insulating sheath: this element allows the wire to be used at a point with high degree interference during the transmission of information, ensures high reliability of the system both in street conditions during thunderstorms, and protection against electromagnetic interference.

The modern market offers products for installation in buildings, underground structures, door/window openings, ventilation ducts, outdoor conditions. The choice is made based on the compliance of the technical characteristics of the wire with the purposes of operation.

Basic requirements for a security alarm cable

Products for fire systems must meet the following criteria:

• Fire resistance, ability to work in case of fire
• Low smoke emission
• No halogen particles in the composition
• Copper core diameter from 0.5 mm (when working indoors)

Wire requirements for burglar alarm:

• High strength to mechanical stress, influence of moisture, chemical substances(especially relevant when laying wires in open areas)
• Fire resistance (when installed in a hazardous area)
• No toxic substances inside the insulating layer
• Section diameter from 0.22 mm

Cable production Russian production must meet the requirements of GOST R 53315-2009. The marking contains the type of design with the corresponding index (ng-FRLS or ng-FRHF), fire safety class. Foreign products have the designations H and E180 in the labeling: this means the use polymer composition for insulating a conductor that is not subject to ignition and corresponds to a fire resistance class with a period of 180 minutes. A high-quality cable for fire alarm systems has a certificate containing information on compliance with international technical standards fire resistance, insensitivity to the spread of fire, the amount of volatile substances released by halogen acids, changes in smoke density.

Types of wires and cables used