Security systems fire alarm(OPS) are designed to determine the fact of unauthorized entry into a protected object or the appearance of signs of fire, issue an alarm signal and turn on actuators (light and sound alarms, relays, etc.). In terms of their construction ideology, fire alarm systems are very close to each other and at small facilities, as a rule, they are combined on the basis of a single control unit - a receiving and control device (PPK) or a control panel (CP). In general, these systems include:

• technical means of detection (detectors);
• technical means of collecting and processing information (reception and control devices, notification transmission systems, etc.);
• technical means of warning (sound and light alarms, modems, etc.).

Technical means detection- These are detectors built on various physical principles of operation. A detector is a device that generates a specific signal when a particular controlled environmental parameter changes. Based on their area of ​​application, detectors are divided into security, security-fire and fire detectors. Currently, security and fire detectors are practically not produced and are not used. Security detectors, based on the type of controlled area, are divided into point, linear, surface and volumetric. According to the principle of action - electric contact, magnetic contact, shock contact, piezoelectric, optical-electronic, capacitive, sound, ultrasonic, radio wave, combined, combined, etc.

Fire detectors are divided into manual and automatic detectors. Automatic fire detectors are divided into thermal detectors, which respond to an increase in temperature, smoke detectors, which respond to the appearance of smoke, and flames, which respond to optical radiation. open flame.

Security detectors

Electric contact detectors- the simplest type of security detectors. They are a thin metal conductor (foil, wire), specially fixed to the protected object or structure. Designed to protect building structures (glass, doors, hatches, gates, non-permanent partitions, walls, etc.) from unauthorized penetration through them by destruction.

Magnetic contact (contact) detectors designed to block various building structures from opening (doors, windows, hatches, gates, etc.). A magnetic contact detector consists of a sealed magnetically controlled contact (reed switch) and a magnet in a plastic or metal non-magnetic housing. The magnet is installed on the moving (opening) part of the building structure (door leaf, window sash, etc.), and the magnetically controlled contact is installed on the stationary part (door frame, window frame, etc.). For blocking large opening structures (sliding and swing gates), having significant backlash, electric contact detectors such as travel limit switches are used.

Impact detectors are designed to block various glazed structures (windows, showcases, stained glass, etc.) from breaking. The detectors consist of a signal processing unit (SPU) and from 5 to 15 glass break sensors (GBS). Location components detectors (BOS and DRS) is determined by the number, relative position and the area of ​​blocked glass panels.

Piezoelectric detectors are designed to block building structures (walls, floors, ceilings, etc.) and individual objects (safes, metal cabinets, ATMs, etc.) from destruction. When determining the number of detectors of this type and their installation location on the protected structure, it is necessary to take into account that it is possible to use them with 100% or 75% coverage of the blocked area. The area of ​​each unprotected section of the blocked surface should not exceed 0.1 m2.

Optical-electronic detectors are divided into active and passive. Active optical-electronic detectors generate an alarm notification when the reflected flow changes (single-position detectors) or the cessation (change) of the received flow (two-position detectors) of infrared radiation energy caused by the movement of the intruder in the detection zone. The detection zone of such detectors has the form of a “radial barrier” formed by one or more located in vertical plane parallel narrow beams. The detection zones of different detectors differ, as a rule, in the length and number of beams. Structurally, active optical-electronic detectors, as a rule, consist of two separate blocks - an emission unit (RU) and a receiver unit (RU), separated by a working distance (range).

Active optical-electronic detectors are used to protect internal and external perimeters, windows, showcases and approaches to individual objects (safes, museum exhibits, etc.).

Passive optical-electronic detectors are the most widely used because, with the help of optical systems specially designed for them (Fresnel lenses), detection zones of various shapes and sizes can be easily and quickly obtained and used to protect premises of any configuration, building structures and individual objects .

The operating principle of the detectors is based on recording the difference between the intensity of infrared radiation emanating from the human body and the background ambient temperature. The sensitive element of the detectors is a pyroelectric transducer (pyroelectric receiver), on which it focuses infrared radiation using a mirror or lens optical system (the latter are the most widely used).

The detection zone of the detector is a spatial discrete system consisting of elementary sensitive zones in the form of rays located in one or several tiers or in the form of thin wide plates located in a vertical plane (“curtain” type). Conventionally, detector detection zones can be divided into the following seven types: wide-angle, single-tier “fan” type; wide-angle multi-tiered; narrowly directed “curtain” type, narrowly directed “beam barrier” type; panoramic single-tier; panoramic multi-tiered; multi-tiered conical.

Due to the possibility of forming detection zones of various configurations, passive infrared optical-electronic detectors have universal application and can be used to block volumes of rooms, places where valuables are concentrated, corridors, internal perimeters, passages between racks, window and door openings, floors, ceilings, rooms with small animals, storage facilities and so on.

Capacitive detectors designed for blocking metal cabinets, safes, individual items, and creating protective barriers. The operating principle of detectors is based on a change in the electrical capacitance of the sensitive element (antenna) when a person approaches or touches a protected object. In this case, the protected item must be installed on a floor with good insulating coating or on an insulating pad.

It is allowed to connect several metal safes or cabinets to one detector in a room. The number of connected items depends on their capacity, design features premises and is specified when setting up the detector.

Sound (acoustic) detectors designed to block glazed structures (windows, shop windows, stained glass windows, etc.) from breaking. The operating principle of these detectors is based on a non-contact method of acoustic monitoring of the destruction of a glass sheet by vibrations that arise during its destruction in the audio frequency range and propagating through the air.

When installing the detector, all areas of the protected glazed structure must be within its direct vision.

Ultrasonic detectors are designed to block volumes of enclosed spaces. The operating principle of the detectors is based on recording disturbances in the field of elastic waves in the ultrasonic range, created by special emitters, when moving in the detection zone of a person. The detection zone of the detector has the shape of an ellipsoid of rotation or teardrop shape.

Due to low noise immunity, they are currently practically not used.

Radio wave detectors designed to protect the volumes of enclosed spaces, internal and external perimeters, individual objects and building structures, and open areas. The operating principle of radio wave detectors is based on recording disturbances electromagnetic waves Microwave range emitted by the transmitter and registered by the detector receiver when a person moves in the detection zone. Detector detection area (same as ultra sound detectors) has the shape of an ellipsoid of revolution or a teardrop shape. The detection zones of different detectors differ only in size.

Radio wave detectors come in one- and two-position types. Single-position detectors are used to protect the volumes of enclosed spaces and open areas. Two-position - for protecting perimeters.

When choosing, installing and operating radio wave detectors, you should remember one of their features. For electromagnetic waves in the microwave range, some building materials and structures are not an obstacle (screen) and they freely, with some attenuation, penetrate through them. Therefore, the detection zone of a radio wave detector may, in some cases, extend beyond the protected premises, which can cause false alarms. Such materials and structures include, for example, thin plasterboard partitions, windows, wooden and plastic doors and so on. Therefore, radio wave detectors should not be oriented towards window openings, thin walls and partitions behind which movement of large objects and people is possible during the security period. It is not recommended to use them at facilities near which powerful radio transmitting equipment is located.

Combined detectors are a combination of two detectors, built on different physical detection principles, combined structurally and circuitously in one housing. Moreover, they are schematically combined according to the “and” scheme, i.e. only when both detectors are triggered, an alarm notification is generated. The most widely used combination is passive infrared and radio wave detectors.

Combined security detectors have very high noise immunity and are used to protect the premises of objects with complex noise conditions, where the use of other types of detectors is impossible or ineffective.

Combined detectors are two detectors built on different physical detection principles, combined structurally in one housing. Each detector operates independently of the other and has its own detection zone and its own output for connection to the alarm loop. The most widely used combination is passive infrared and audible detectors. There are other combinations as well.

Alarm Detectors are intended for manual or automatic submission of an alarm notification to the internal security console of a facility or to internal affairs bodies in cases of a possible criminal attack on employees, clients or visitors to the facility.

Various manual and foot operated buttons and pedals based on magnetic and electric contact detectors are used as alarm detectors. As a rule, such detectors are locked in the pressed state and return to initial position only possible with a key.

For the same purposes, special mini-alarm systems operating over a radio channel have been developed and are used. They include a receiver connected to a receiving and control device or control panel, and several wearable transmitter key fobs for wireless transmission alarm notifications. Some key fobs include a fall sensor. The range of such systems ranges from several tens to several hundred meters.

Trap detectors occupy a special place among alarm detectors. They are designed to provide an alarm when there is an attempt to steal money or rob a protected object, regardless of the actions of personnel. They are an imitation of a pack of money in a bank package with a volume of 100 bills, in which a magnet is mounted, and in a special stand on which the pack is located, a magnetic sensor (reed switch).

When removing (moving) an imitation bundle of money from the stand, the contacts of the magnetic sensor open and an alarm notification is sent to the facility’s security console. There are similar trap detectors, in which, together with a magnet, a special cartridge containing colored (orange) smoke with a volume of 5 m is built in. 2 The smoke composition is sprayed with a time delay (3 minutes) after the magnetic sensor is triggered.

Types of interference and their possible sources

During operation, detectors are exposed to various interfering factors, among which the main ones are: acoustic interference and noise, vibrations of building structures, air movement, electromagnetic interference, changes in temperature and humidity of the environment, technical weakness of the protected object.

The degree of impact of interference depends on its power, as well as on the operating principle of the detector.

Acoustic interference and noise are created by industrial installations, vehicles, household radio equipment, lightning discharges and other sources. Examples of acoustic interference are given in table 1.

Table 1. Examples of acoustic interference

This type of interference causes the appearance of inhomogeneities in the air environment, vibrations of non-rigidly fixed glazed structures and can cause false alarms of ultrasonic, sound, impact and piezoelectric detectors. In addition, the operation of ultrasonic detectors is influenced by high-frequency components of acoustic noise.

Vibrations of building structures caused by railway and subway trains, powerful compressor units, etc. Shock contact and piezoelectric detectors are especially sensitive to vibration interference; therefore, these detectors are not recommended for use in objects subject to such interference.

Air movement in a protected area is caused mainly by heat flows nearby heating devices, drafts, fans, etc. Most susceptible to influence air flow ultrasonic and passive optical-electronic detectors. Therefore, these detectors should not be installed in places with noticeable air movement (in window openings, near batteries central heating, near ventilation openings, etc.).

Electromagnetic interference are created by lightning discharges, powerful radio transmitting means, high voltage lines power transmission, power distribution networks, electric transport contact networks, installations for scientific research, technological purposes, etc.

Radio wave detectors are most susceptible to electromagnetic interference. Moreover, they are more susceptible to radio interference. The most dangerous electromagnetic interference is interference from the power supply. They arise when switching powerful loads and can penetrate into the input circuits of the equipment through the power supply inputs, causing false alarms. A significant reduction in their number is achieved by the use and timely Maintenance backup power sources.

Avoid exposure to electromagnetic interference from networks alternating current The operation of detectors is made possible by compliance with the basic requirement for the installation of low-voltage connecting lines: the laying of the power lines of the detector and the alarm loop must be carried out parallel to the power networks at a distance between them of at least 50 cm, and their intersection must be made at a right angle.

Changes in ambient temperature and humidity at a protected facility may affect the operation of ultrasonic detectors. This is due to the fact that the absorption of ultrasonic vibrations in the air is highly dependent on its temperature and humidity. For example, when the ambient temperature increases from +10 to +30 °C, the absorption coefficient increases by 2.5-3 times, and when the humidity increases from 20-30% to 98% and decreases to 10%, the absorption coefficient changes by 3-4 times times.

A decrease in the temperature at an object at night compared to daytime leads to a decrease in the absorption coefficient of ultrasonic vibrations and, as a consequence, to an increase in the sensitivity of the detector. Therefore, if the detector was adjusted during the day, at night, interference sources that were outside this zone during the adjustment period may enter the detection zone, which can cause the detector to operate.

Technical weakness of objects has a significant impact on the stability of the operation of magnetic contact detectors used to block elements of building structures (doors, windows, transoms, etc.) from opening. In addition, poor technical strength can cause false alarms of other detectors due to drafts, vibrations of glazed structures, etc.

It should be noted that there are a number specific factors, causing false alarms of detectors only of a certain category. These include: the movement of small animals and insects, fluorescent lighting, radio permeability of elements of building structures, direct contact with detectors sun rays and car headlights.

Movement of small animals and insects can be perceived as the movement of an intruder by detectors whose operating principle is based on the Doppler effect. These include ultrasonic and radio wave detectors. The influence of crawling insects on detectors can be eliminated by treating their installation sites with special chemicals.

When fluorescent lighting is used at an object protected by radio wave detectors, the source of interference is the column of ionized gas of the lamp flashing at a frequency of 100 Hz and the vibration of the lamp fittings at a frequency of 50 Hz.

In addition, fluorescent and neon lamps create continuous fluctuation interference, and mercury and sodium lamps create pulsed interference with a wide range of frequencies. For example, fluorescent lamps can create significant radio interference in the frequency range 10 -100 MHz or more.

The detection range of such light sources is only 3-5 times less than the detection range of a person, so during the period of protection they must be turned off, and incandescent lamps must be used as emergency lighting.

Radio permeability of building structure elements It can also cause false triggering of a radio wave detector if the walls are thin or there are thin-walled openings, windows, and doors of significant size.
The energy emitted by the detector can extend outside the room, and the detector detects people passing outside, as well as passing vehicles. Examples of radio permeability of building structures are given in table 2.

Table 2. Examples of radio permeability of building structures

Thermal radiation lighting fixtures may cause false alarms of passive optical-electronic detectors. This radiation is comparable in power to human thermal radiation and can trigger detectors.

In order to eliminate the impact of this interference on passive optical-electronic detectors, it can be recommended to isolate the detection zone from the effects of radiation from lighting devices. Reducing the influence of interfering factors, and, consequently, reducing the number of false alarms of detectors, is mainly achieved by complying with the requirements for the placement of detectors and their optimal configuration at the installation site.

IN table 3 types and sources of interference are given and ways to eliminate them are given.

Table 3. Sources of interference and methods for eliminating them

When choosing the types and number of detectors to protect a particular facility, the following should be taken into account:
- required level of security reliability of the facility;
- costs of purchasing, installing and operating the detector;
- construction and structural characteristics of the object;
- tactical and technical characteristics of the detector.
The recommended type of detector is determined by the type of structure being blocked and the method of physical impact on it according to Table 4.

Fire detectors

Fire detectors are the main elements of automatic fire and security fire alarm systems.

Based on the method of actuation, fire detectors are divided into manual and automatic. IN manual call points There is no fire detection function; their action is reduced to transmitting an alarm message to the electrical circuit of the alarm loop after a person detects a fire and activates the detector by pressing the corresponding start button.

Automatic fire detectors operate without human intervention. With their help, a fire is detected based on one or more analyzed signs and a fire notification is generated when the controlled level is reached. physical parameter set value. The controlled parameters may include increased air temperature, release of combustion products, turbulent flows hot gases, electromagnetic radiation etc. In accordance with the detected primary signs of fire, detectors, as mentioned earlier, are divided into thermal, smoke, flame, gas and combined. It is also possible to use other signs of fire. Combined detectors respond to two or more parameters that characterize the appearance of a fire.

Heat detectors can use a method of generating an analyzed signal, allowing them to respond not only to an increase in absolute value temperature above the maximum set threshold, but also by exceeding the rate of increase of its limit value. Therefore, in accordance with the nature of the reaction to a change in the controlled sign, they are divided into maximum, differential and maximum-differential. Smoke fire detectors, based on their operating principle, are divided into optical-electronic and ionization.

According to the method of power supply, fire detectors are divided into:

• powered by an alarm loop from a control panel or control panel;
• powered by a separate external power source;
• powered by built-in internal source power supply (autonomous fire detectors).

The detector detection zone is the space near the detector, within which its operation is guaranteed when a fire occurs. Most often, this parameter is expressed in units of area (m2) controlled by the detector with the required reliability. As the detector installation height increases, the area controlled by one detector decreases. If the installation height is higher than the specified maximum, effective detection of a fire source by the detector is not guaranteed.

For light detectors, the protected area is determined by the maximum detection range of an open test fire and the viewing angle, which depends on the design of the optical system.

Fire detectors must provide reliable detection of a fire in specific protected premises. To do this, when choosing a detector, it is necessary to take into account the probable nature of the fire and the process of development over time of the main factors of the fire: increased temperature, smoke concentration, light radiation at different points in the room. Depending on the type and quantity of combustible materials in a fire, one or more detectable signs may predominate.

More often than not, a fire is accompanied by the release of smoke. initial stage, therefore, in most cases it is most advisable to use smoke detectors. When choosing a smoke detector, it should be taken into account that ionization (radioisotope) and optical-electronic smoke detectors have different sensitivity to combustion products, the smoke particles of which have different colors and sizes. Optical-electronic point detectors respond better to light smoke, typical of cellulose-containing materials, as well as smoke consisting of small aerosol particles. Ionization detectors have a relatively higher sensitivity to combustion products that emit black smoke with larger particles (for example, when burning rubber).

Premises where fire is most likely to occur quick appearance open flame, it is preferable to equip it with light detectors.

It is advisable to install heat detectors, first of all, in cases where a significant fire source is provided and, therefore, during a fire there will be intense heat release.

When choosing a detector, it is also necessary to take into account special Additional requirements to their design and operating principle. For example, radioisotope detectors are not recommended for installation in residential premises and children's institutions. In explosive areas, detectors with a special design must be installed.

Calculation of the total number of detectors and determination of their installation locations should be carried out taking into account the characteristics of the premises, as well as the requirements of regulatory and technical documentation. The latter includes relevant documents regulating general issues of design and installation of fire automatic systems, fire and security alarm systems and complexes, as well as operational documentation for the corresponding type of detector.

Fire detectors created using the fourth generation element base: specialized controllers and microprocessors are becoming increasingly widespread.

A common feature of such detectors with expanded tactical and technical capabilities is their use for collaboration only special devices(control panels) that are part of the fire alarm system of the corresponding company.

Application of funds computer technology allows you to create addressable fire detectors that transmit to CPU control panel information about its location, which ensures an accurate reconstruction of the picture and analysis of the process of occurrence and development of a fire. They carry out automatic or upon request from the center performance monitoring and digital transmission of data on the parameters of their functioning. In such detectors, if necessary, it is possible to adjust the sensitivity when conditions change external environment. Analogue type detectors can also transmit information about the level of the controlled parameter. The range of detectors is being expanded through the use of new technologies. For example, modern foreign linear heat detectors (cable type) detect the difference between normal and elevated temperature, which allows you to generate an alarm signal even before the start of a fire (smoke or fire) if the controlled object overheats. The signal is transmitted in analog form from the detector to a special control panel, which allows you to determine the distance to the overheated area. Such detectors can be effectively used to monitor objects with electrical equipment, rooms with false ceilings, cable routes and channels.

Technical means of collecting and processing information

Technical means for collecting and processing information include reception and control devices, control panels, alarm and trigger devices, notification transmission systems, etc. They are designed for continuous collection of information from technical detection devices (detectors) included in alarm loops, analysis of the alarm situation at the facility and its display, control of local light and sound annunciators, indicators and other devices (relay, modem, transmitter, etc.), as well as the generation and transmission of notifications about the state of the object to a central post or central monitoring console. They also provide security and disarming of the object (premises) according to adopted tactics, as well as, in some cases, power supply to detectors.

Reception and control devices are classified according to information capacity (the number of signals controlled by the alarm loop) into devices of small (up to 5 alarm loops), medium (from 6 to 50 alarm loops) and large (over 50 alarm loops) information capacity. In terms of information content, devices can be small (up to 2 types of notifications), medium (from 3 to 5 types) and large (over 5 types) information content.

Notification transmission systems are classified according to information capacity (the number of protected objects) into systems with constant information capacity and with the possibility of increasing information capacity.

Based on information content, systems are divided into systems of small (up to 2 types of notifications), medium (from 3 to 5 types) and large (over 5) information content.

Based on the type of communication lines (channels) used, systems are divided into systems using telephone network lines (including switched ones), special communication lines, radio channels, combined communication lines, etc.

Based on the number of directions of information transmission, they are divided into systems with one- and bidirectional information transmission (with the presence of a return channel).

According to the algorithm for servicing objects, message transmission systems are divided into non-automated systems with manual tactics of arming (disarming) objects under protection (disarming) after telephone conversations with the control panel attendant and automated systems with automatic arming and disarming (without telephone conversations).

According to the method of displaying information received at the centralized monitoring console, notification transmission systems are divided into systems with individual or group display of information in the form of light and sound signals, with information displayed on the display using devices for processing and storing a database.

Control panels correspond to domestic control panels for the main tasks they solve. Let us also clarify the concepts of a security zone (a term used in foreign literature) and an alarm loop used in domestic literature. Let us immediately note that these concepts are different.

Alarm loop- This electrical circuit, connecting the output circuits of detectors, including auxiliary elements (diodes, resistors, etc.), connecting wires and boxes and designed to issue notifications of intrusion, attempted intrusion, fire, malfunction, and in some cases for supplying power to detectors.

Thus, the alarm loop is designed to monitor the state of a certain protected area.

Zone- this is a part of a protected object, controlled by one or more alarm loops. Therefore, the term “zone” used in descriptions of foreign equipment is in this case synonymous with the term “alarm loop”.

Modern multifunctional control rooms have ample capabilities for organizing security, fire and security-fire alarm systems. Knowing these possibilities will allow you to do right choice CP, the characteristics and parameters of which most fully satisfy the solution of the assigned tasks for the protection of a specific object.

The structure of the alarm system organized on the basis of the control center will be largely determined by the way the alarm loops are connected, which affects functional characteristics of the organized security system and largely determines the cost of installation work. According to the method of connecting the loops, we can distinguish following types KP:

• with trains radial structure;
• with a tree structure;
• address.

In a control panel with radial structure cables, each cable is connected directly to the panel itself. This structure is justified with a small number of loops (usually up to 16) and on objects that do not require the organization of remote loops. They are usually used for small and medium-sized objects.

CPs with a tree structure have a special information bus consisting of several wires (usually 4). Expanders are connected to this bus. In turn, radial cables are connected to the expanders. Several basic ones can also be connected to the control panel itself radial loops. The total number of loops is usually in the range of 24-128. The expanders monitor the status of the loops connected to them, encode information about their status and transmit it via the information bus to the control panel, which has an indication of the status of all loops. Such control points are used to build security systems for medium and large objects.

Addressable control panels using loops with addressable detectors stand somewhat apart from the rest and are usually used to create fairly complex integrated security systems for large and critical objects. It is obvious that addressable detectors are more complex and more expensive than conventional ones, and their application and advantages are fully manifested in complex and large objects.

There are addressable CPs that have different configurations of their loops:

• radial;
• ring;
• circular with radial branches.

The ring loop has a fairly serious advantage. If it is damaged (broken), it retains its functionality, since the information exchange line is maintained. When the loop is short-circuited, special devices, loop separators, disconnect the shorted section, and the rest of the loop continues to function.

Reception and control devices (RPK) and control panels (CP) are the main elements that form the information and analytical system of security, fire or security-fire alarm systems at the facility. Such systems can be autonomous or centralized. In the first case, the control panel or control panel is installed in a security room (point) located at a protected facility. With centralized security, an object complex of technical means, formed by one or several control panels (CP), forms an object subsystem of security and fire alarms, which, using a notification transmission system (NTS), transmits in a given form information about the state of the object to the central monitoring console (MSC), located in the center for receiving alarm notifications (centralized security point - ARC). Information generated by the control panel or control center during autonomous and centralized security is transmitted to employees of special facility security services, who are entrusted with the functions of responding to alarm notifications coming from the facility.

Key terms used in this section:

1. Detector detection area- part of the space of the protected object in which the detector issues an alarm when the controlled parameter exceeds the threshold value.
2. Detector sensitivity - numerical value controlled parameter, when exceeded, the detector should be triggered.
3. Optical density of the medium- the decimal logarithm of the ratio of the radiation flux passing through a smoke-free environment to the radiation flux weakened by the environment when it is partially or completely smoked.

reference Information

Requirements for the placement of fire detectors in accordance with NPB 88-2001 “Fire extinguishing and alarm installations. Design norms and rules"

In accordance with NPB 88-2001 “Fire extinguishing and alarm installations. Design Codes and Rules", the area controlled by one point smoke detector, as well as maximum distance between the detectors and the wall, must be determined by table 5

Table 5. Requirements for placement of smoke detectors

When monitoring a protected area with two or more linear smoke detectors (LSDS), the maximum distance between their parallel optical axes, the optical axis and the wall, depending on the installation height of the fire detector blocks, should be determined by table 6.

Table 6. Requirements for the placement of linear smoke detectors

In rooms with a height of over 12 m and up to 18 m, detectors should be installed in two tiers, in accordance with table 7.

Table 7. Requirements for the placement of linear smoke detectors for two-tier placement

The area controlled by one point heat detector, as well as the maximum distance between the detector and the wall, must be determined by table 8, but not exceeding the values ​​specified in technical conditions and passports for detectors.

Table 8 Requirements for the placement of heat detectors

Classes of thermal fire detectors, in accordance with NPB 85-2000 “Thermal fire detectors. Technical requirements fire safety. Test methods"

In accordance with NPB 85-200 “Thermal fire detectors. Technical requirements for fire safety. Test methods", maximum, maximum-differential detectors and detectors with differential characteristics, depending on temperature and response time, are divided into ten classes: A1, A2, A3, B, C, D, E, F, G, H (see . table 9).

Table 9. Classes of maximum differential detectors

To create an appropriate level of security at a facility, it is necessary to install security and fire alarms. The fire alarm system is a combination of technical means for detecting a fire and identifying attempts of illegal access to the protected perimeter. The two subsystems have common communication channels, similar algorithms for receiving, processing and transmitting information and alarm signals. In order to save money, it is best to combine them.

OPS systems are the most common today. These protective lines allow you to create an appropriate level of security for the protected object.

Thanks to a combination of technological means, the operation of such subsystems is based on several types of alarm systems: security, fire and emergency. The security alarm detects attempts at illegal entry, the fire alarm detects the presence of a fire, the emergency alarm warns of emergency situations (gas leak, water pipe break, etc.).

What are the main tasks of security and fire systems?

Fire alarm systems are built on a combination that are integrated with each other. However, the goals set are individual for each subsystem. The following fire alarm tasks are distinguished:

• Reception, processing, transmission of information about the occurrence of a fire;
• Determining the location of the fire;
• Transmitting a command to the automatic fire extinguishing mechanism;
• Starting the smoke removal subsystem.

The tasks of the security alarm are:

• Detection of all attempts of illegal access to the protected area;
• Recording the place and time of violation of access rules;
• Transferring information to a computerized control panel.

Despite the fact that individual goals are identified for both subsystems, the installation of fire alarm systems at an enterprise is designed to fulfill one common task: to ensure a timely response to a conditioned factor and the transfer of relevant information about the ongoing event.

The video shows how the fire and security alarm works:

Comprehensive composition of integrated security and fire systems

OPS systems in their own way complex composition may differ from each other. First of all, it depends on the tasks that the security and fire alarm system performs. As a rule, this complex includes three main categories of equipment:

• A device for centralized monitoring and control of the operation of alarm systems (a computer equipped with specialized software, a central control panel, a receiving and control mechanism);
• Devices for receiving, collecting and analyzing information coming from fire alarm sensors;
• Signaling and sensor mechanisms (various types of sensors and notification devices).

Management of the operation of the security system and control over its implementation is carried out by a centralized device. Despite this, each alarm can be controlled by separate enterprise security services. When installing such protective circuits, the autonomy of each subsystem as part of the entire complex is maintained.

Fire alarm systems are equipped with sensors that can detect the occurrence of an alarm. As a rule, the technical characteristics of the sensor determine the parameters of the entire protection circuit. The mechanisms for receiving, collecting and analyzing information coming from fire alarm sensors are actuators. They allow you to execute a programmed algorithm of actions in response to an received alarm signal.

A special feature of the fire alarm system is that it can be installed in two ways. The first is an alarm system with closed (local) security, i.e., arming is carried out inside the facility with the transfer of relevant information to the security service of the institution. The second is arming in special units (private or non-departmental) and the fire service of the Ministry of Emergency Situations.

Classification of OPS system complexes

Security and fire alarm systems of various types can be installed at a protected facility:

• Non-addressable (analog);
• Targeted (survey and non-survey);
• Combined (addressable-analog).

The non-addressable fire alarm system operates on a simple principle. The perimeter of the protected object is divided into several parts, in each of which a loop is laid. It combines several notification mechanisms. The loop receives information from the detector immediately after it is triggered. The disadvantage of this type protective circuit is the possibility of false operation of the device. The functionality of the loop and detectors can only be checked during a technical inspection. The control area is limited to one loop, and the exact location of the occurrence can be determined. emergency situation impossible. Centralized control is performed by security and fire panel mechanisms. At large facilities, when installing such systems, it is necessary to perform a large amount of work on laying connecting wires.

The addressable fire alarm system can be interrogated or non-interrogated. When installing this type of protective line on the loop, address sensors. When triggered, the code of a specific sensor is indicated. Non-interrogation lines are threshold lines based on their operating principle. If any notification device fails, there is no connection with the receiving and control mechanism. A feature of polling systems is the periodic submission of a request about the functionality of the notification mechanism. In survey schemes, the false alarm rate is reduced.

Today the most common and effective are combined fire and security complexes. In practice, they are called analog addressable.

It is possible to connect various types of sensors to this system. All information is processed by specialized electronic computing equipment. The system independently determines the type of sensor and sets the algorithm for its operation. The combined line allows you to quickly process information and make appropriate decisions. Expansion of such a subsystem with additional protective lines is possible without much effort and expense.

Types of fire and security notification devices

The fire and security system must be equipped with sensors. Fire sensors are divided into:

• By the method of transmitting the received information (analog and threshold);
• By location on the protected perimeter (external and internal);
• Based on the principle of recording changes in space (volumetric, linear, surface);
• According to the method of monitoring individual items (local or point);
• By signal generation method (active, passive);
• According to the operating factor (thermal, light, smoke, ionization, manual, combined);
• Based on the principle of physical impact (capacitive, seismic, radio beam, closing).

Among security sensors, the following subtypes are distinguished (based on the type of notification mechanisms used):

• Contact;
• Magnetic;
• Electric contact;
• Infrared passive;
• Active;
• Volumetric radio waves;
• Volumetric ultrasonic;
• Microwave;
• Acoustic;
• Capacitive;
• Vibrating;
• Barometric.

On video - more information about security and fire alarms:

Video surveillance and security alarm system – effective integration of devices

Video surveillance systems installed at the facility allow you to monitor the protected area around the clock in real time. Modern solution is a combination of security guard and video monitoring. Installation of such integrated systems will allow faster and better detection of the presence of a flame in a room or an attempt to illegally enter a protected area. Today, there are video cameras that can detect smoke entering the lens, the presence of fire, or other indicators of risk.

Thanks to the integration of a video surveillance device into the security system, the operation of security and fire installations is greatly facilitated. Video cameras allow you to promptly identify the location of smoke or the presence of a flame. This combination also helps to notify people of danger in time and carry out evacuation measures. Video cameras allow you to continuously monitor events taking place both inside the structure and in the surrounding area.

All data in the installed video surveillance subsystem is stored in an archive. Access to the archive is open at any time.

When introducing such a system into the work of an existing security guard, cameras from various leading manufacturers are used. Video surveillance on site has a number of capabilities:

• Lighting control;
• Sending text messages to persons responsible for ensuring safety, including fire safety, about the condition of the facility or the occurrence of an emergency;
• Immediate notification of building security sector employees;
• In the event of an emergency, it is possible to shut down engineering, communication and air conditioning subsystems;
• Recording and playing video files;
• Mode setting;
• Setting the storage time for files in the archive;
• Performing scaling of individual frames;
• Search, view and analyze images according to the necessary parameters (by camera number, date, time, event, room).

Fire is a terrible element that claims thousands of lives every year. No less problematic is the protection of property of organizations, enterprises and individuals. To prevent casualties, death and theft material assets Security and fire alarm systems, or, in short, OPS, are installed at facilities. With the help of the technical and hardware included in it, security and fire alarms are used to prevent and minimize losses of enterprises and organizations. With this approach, in addition to timely notification, the fact, place and time of violation of the protected area is additionally recorded.

Functions of a modern security system:

• Perimeter security;
• Fire warning;
• Call for help (alarm function);
• Warning about some emergency situations in life support systems of buildings (gas leaks, water supply, etc.).

The installation of a fire alarm is prescribed by the fire safety law; the installation of a burglar alarm at a facility is most often mandatory requirement enterprises providing security services, as well as insurance companies.

Development, design, installation and maintenance of security and fire alarm systems of any generation is one of the most popular services of our company GEFEST-ALARM LLC.

Why do you need a security and fire alarm system?

As mentioned above, the purpose of the security and fire alarm system is to timely notify responsible personnel and people at the facility about emergency situations, such as a fire or a violation of the perimeter. This is one of the oldest, most effective and well-proven security systems.

The combination of security and fire alarms into one system is caused by purely economic considerations. After all, security and fire systems have much in common, besides the obvious purpose of saving lives and property. These are identical communication channels, algorithms for processing information received from sensors, sending alarms and signals, and many technical means are similar.

Composition and means of security and fire alarm systems

Technical means of security and fire alarm systems are quite diverse. The composition of a modern security system includes the following tools and components.

• Sensors and alarm detectors, the purpose of which is to react (automatically trigger) to a given alarm event. They are infrared, vibration, optical, vibration, etc.
• Communication lines – wired and wireless, including via the Internet;
• Receiving and control devices (RPC, “controllers”) - the purpose of this OPS tool is to receive and process, according to given operation algorithms, signals coming from sensors and control actuators, that is, turning on and off sensors if they have triggered falsely, turning on an alert and etc.
• Actuating devices are their purpose to perform a given job. This means - giving a signal, dialing rescue numbers, activating other systems, for example, fire extinguishing or smoke removal.

Modern means security and fire alarm systems include complex electronic components, and are often controlled by a computer, so they also include software.

Types of fire and security alarm systems

There are also quite a few types of OPS currently in use. Based on their operating principle, they can be divided into 3 main categories:

• Non-addressable (analogue) fire and security alarm systems, today used mainly in small objects, the signal when one sensor is triggered is sent along the entire cable;
• Addressed fire alarm systems allow you to determine the location of a fire or perimeter violation using communication protocols; they can be polling or non-polling;
• Combined OPS systems are the most common due to the universality of the price of the means and components.

Employees of Gefest-Alarm LLC have great experience in the design and installation of security and fire alarm systems and means, we can implement and help to coordinate with the regulatory authorities any fire alarm systems at facilities of various sizes. We offer warranty and post-warranty service with all the necessary permits to carry out such work.

The head of an enterprise or the owner of any real estate must take care to protect his property from negative impact man-made disasters and intruders. Ensuring the safety of the premises and all objects located in it can be ensured not only by specially trained people standing near the doors. Modern technologies allow you to ensure the safety of the premises thanks to specially designed interconnected subsystems into one system. Many people are familiar with fire response systems and security alarm systems.

Security and fire alarms: concept and its tasks

An integrated system that includes fire and security alarm systems is called a fire and security system. This system is becoming very popular today. Most often, the system is part of an integrated security complex. The main function of the security and fire alarm system is provided for by GOST 2642-84. Its main task is to receive, process and transmit, in the prescribed manner, information about a fire that has occurred at a protected facility or the entry of unauthorized people into it.

The main functions of the fire security system are:

• monitoring the condition of the territory throughout the day;
• detection of even the slightest fire at the facility;
• determining the exact location of the fire or intrusion;
• information must be provided in an understandable form;
• responding to attempts to hack and break the system;
• response to detection device malfunctions.

The security and fire alarm system is a complex system and is quite expensive, but according to consumer reviews and experiments, it is the only reliable electronic device protection.

Modern security equipment includes several subsystems that depend on executive functions:

• security - the device reacts to any external penetration;
• fire - the device responds to any signs of fire;
• alarm – the device calls the necessary help if a signal of an unexpected attack appears;
• emergency – the device gives a signal when certain emergency situations occur: gas leak, water breakthrough, water overflow, etc.

Each subsystem has its own strictly established goals. All subsystems are combined into one security system by integrating with each other.

What does an alarm system consist of that provides protection against fire and theft?

The components of the fire and intruder control system are:

• sensors that are receivers of danger signals;
• equipment that receives a danger signal;
• elements that notify of an emerging danger
• communication installations;
• autonomous power supply (generator, battery);
• programs that ensure the correct operation of the device.

How the alarm works

The principle of operation of a security and fire alarm system is very simple. Sensors become the main receivers of information about a fire, the penetration of thieves or ill-wishers. About a fire or attack, sensor mechanisms transmit information to the control panel, which is responsible for collecting data, and in more complex integrated systems, information is transmitted to the control panel. Once the information reaches its destination, the software triggers the system to respond.

The response itself depends on the system hardware. If the alarm system is supplemented with access control system, then thanks to the transmission of information, locks, gates, turnstiles begin to respond to the signal. During a fire, additional escape doors are opened to avoid preventing people from leaving the danger zone.

If the system is equipped with an automatic fire extinguishing program, then in the event of danger it will necessarily work together with the smoke removal function. It is important when operating a fire alarm to block the power supply, which protects against additional danger.

When thieves enter and receive a signal, the system launches its protection program depending on the type of alarm.

Types of security and fire systems

The modern equipment market presents a variety of choices for security and fire alarm systems. Consumers can choose from systems with a simplified security program, systems with additional sensors for monitoring environmental standards that respond to excess gas, water leakage, temperature or humidity levels.

The main distribution of signaling occurs on:

• Non-addressed;
• Address;
• Addressed surveys;
• Non-survey targeted;
• Combined.

This classification is based on differences in the principle of operation of the alarm.

Based on the principle of operation of hazard detectors, hazards are divided into:

• ultrasonic;
• light detectors;
• vibration detectors;
• radio wave;
• acoustic;
• infrared;
• combined.

The following types of sensors are installed in the fire system:

• smoke responsive;
• responsive to room temperature;
• flame reactive;
• gas responsive;
• multisensory, which includes responding to 4 signs of fire;

All sensors are different from each other, have different degrees of sensitivity and response speed.

The following types of detectors are known in the security system:

• sensors that respond to changes in the distance between the magnet on the doors (windows) and the reed switch;
• detectors that respond to impact or surface damage;
• sensors that respond to any movements inside the security object;
• detectors that respond to approaching or touching a protected object.

Based on the way they react to a particular problem, sensors are divided into active and passive.

Based on the location of the alarm system, the following are distinguished:

• Internal;
• External;
• Combined.

There is a division of the system depending on the equipped sensors:

1. According to the method of obtaining information, they are distinguished: analog and threshold;
2. By location of sensors relative to the room: internal and external;
3. According to the method of responding to changes in space: linear, surface, volumetric;
4. Depending on the response to individual objects: local and point;
5. By action factor: thermal, light, manual, combined, ionization;
6. Depending on the physical impact: closing, capacitive, radio-beam, seismic.

Result of the system

Thanks to the activities of security and fire alarms, many objects are protected from sudden attacks, intrusions, accidents and fires. According to statistics of unauthorized intrusion into objects in our country this system is the safest. It is enough to analyze the statistics to understand the importance of signaling:

• 50% or more percent of unauthorized entry into facilities that have free access for working personnel and visiting clients;
• About 25% of the territories were targets of illegal entry, while they were equipped with mechanical security elements;
• 20% of facilities protected by the access control system were subject to illegal entry;
• 5% of territories equipped with complex electronic systems protection, were subject to illegal actions of intruders.

Managers must be concerned about protecting their facilities and ensuring high level reliability by organizing multi-level system protection.

In this case, alarm sensors are installed at several levels:

• along the outer perimeter of the territory;
• on windows and doors;
• in interior spaces;
• on objects that are considered the most important in the protected area: safes, cabinets, drawers.

Each sensor installation point must be connected to its own separate cell of the device, which monitors the signal from the sensor and responds to it. This allows you to avoid an attacker from bypassing a single point, and also to receive a timely signal about the very first signs of a fire, attack or emergency.

Classification of security and fire systems by type and type can be made according to a number of different parameters. The most obvious one is purpose. There are three large groups here:

TYPES OF SECURITY ALARMS

Can also be used as part of security systems Various types sensors, which are wired and wireless, differ in the way they detect intrusion and process the signal. The principles of constructing security systems may vary depending on their purpose: for a house and cottage, apartment, objects of various organizational and legal forms.

An elementary option is an alarm system consisting of one motion sensor with a built-in GSM module. Despite its apparent simplicity, this type of security is quite reliable and is well suited for protecting small country houses.

In general, the security alarm system uses several types of detectors, which are classified according to their purpose and principle of operation. To ensure reliable security, sensors are used to monitor:

• opening windows and doors;
• breaking of glazed surfaces;
• breach of walls, partitions and ceilings.

The listed equipment is used to protect the perimeter of the premises. In addition, there is a group of sensors that detect movement inside or on the approaches to the object. The selection of specific types of detectors is made taking into account individual characteristics object to be protected.