The OS provides detection and recording of the facts of opening doors and windows, breaking glass, movement of intruders in designated areas and premises placed under protection.
System building
Burglar alarm system is built on the controllers of the two-wire line "S2000-KDL". The use of an address scheme in a security alarm provides the following advantages:- the operator has the ability to control the status (including operability and opening of the case) of each detector separately, and not in groups combined into loops, thus achieving high accuracy in localizing the penetration site for prompt response to alarms;
- a failure of the communication line in the threshold system causes the same alarm as the activation of the detector. In the addressable - it is diagnosed as a malfunction, with the ability to localize the place of damage and the maximum preservation of the operability of the rest of the line;
- it is not required to lay a separate loop to each group of detectors, which, with a large number of rooms, leads to a significant reduction in the number of wiring of alarm loops.
To implement the construction of the OS, the following technical means were used:
- monitoring and control panel (PKU) "S2000M";
- two-wire communication line controllers "S2000-KDL";
- indication blocks "S2000-BI";
- signal-starting blocks "S2000-SP1";
- volumetric optical-electronic addressable security detectors "S2000-IK";
- addressable acoustic security detectors "S2000-ST";
- addressable expanders for two zones "S2000-AR2", with the possibility of connecting non-address magnetic security detectors "IO 102-16 / 1" to them
- vibrating surface addressable security detectors "S2000-B";
- uninterruptible power supplies RIP-24.
According to clause 6.2.1. RD 78.36.003-2002, all premises with permanent or temporary storage of material assets, as well as all vulnerable areas of the building (windows, doors, hatches, ventilation shafts, ducts, etc.), through which it is possible to unauthorized entry into the premises of the facility.
In the security room (room 102) on the 1st floor, the S2000M security and fire control panel, S2000-BI display units are installed, which are designed to display the status of sections in the Orion integrated security system. Also in pom. 102 there are signal-starting blocks "S2000-SP1" and power supplies "RIP-24".
The signal-starting block "S2000-SP1" provides the output of the following signal of the "dry" contact type in the process control system: the signal "Intrusion alarm".
Two-wire communication line controllers "S2000-KDL" and uninterruptible power supplies "RIP-24" are installed in booths for OS equipment on each protected floor of the building.
The facility is equipped with a multi-line security alarm system.
The first line of the security alarm is blocked:
- entrance doors of premises for "opening";
- glazed structures - for "opening" and "destruction" ("breaking") of glass;
Detection of the opening of doors and windows is carried out by magnetic contact detectors "IO 102-16 / 1". IO 102-16/1 detectors are installed on all entrance doors of protected premises and on opening transoms of windows.
To detect the destruction of glazed structures, acoustic detectors "S2000-ST" are used.
The second frontier of the burglar alarm protects the volume of premises for "penetration" with the help of volumetric detectors. In large rooms with a complex configuration, requiring the use of a large number of detectors to protect the entire volume, it is allowed to block only local zones (vestibules between doors, corridors, approaches to valuables and other vulnerabilities).
Optoelectronic detectors "S2000-IK" with a volumetric detection zone are used to detect the movements of people in the protected space of premises.
Detectors security volumetric optical-electronic address "S2000-IK" are installed on the walls of the protected premises, at a height of 2.1 m from the floor.
The third line of the security alarm in the premises is blocked by individual items, safes, metal cabinets, in which valuables are concentrated.
In the weapon storage room (room 109) on the 1st floor, an additional controller of the S2000-KDL two-wire communication line is installed to allocate a separate security zone. Room walls 109 protect against deliberate destruction (hacking) with the help of security vibrating surface addressable detectors "S2000-B".
alarm. For the prompt transmission of messages to the security post about illegal actions against personnel or visitors (for example, robbery, hooliganism, threats), the facility must be equipped with alarm devices (TS).
Alarms are usually installed:
- in vaults, pantries, safe rooms;
- in the premises for the storage of weapons and ammunition;
- in the offices of the management of the organization and the chief accountant;
- at the main entrance and emergency exits to the building;
- in other places at the request of the head (owner) of the facility or on the recommendation of a private security officer
Installation of electrical wiring
Burglar alarm loops in the protected premises should be made with a cable with copper conductors of the KPSVV 1x2x0.75 type.
Lay power lines with VVG-ng LS 3x2.5 wire.
For the exchange of information between the devices of the integrated system "Orion" an interface line is used, made with a cable of the KPSVV 2x2x0.5 type.
Installation of electrical wiring networks of systems is carried out in corrugated PVC pipes and cable channels. With parallel open laying, the distance from the wires and cables of the systems to the power and lighting cables must be at least 0.5 m.
When laying networks - the method, laying routes and lengths of wires and cables are subject to clarification during design and installation on site.
Introduction
The relevance of research.
Fire and security alarm system - a set of technical means designed to detect a fire, process, transmit a fire notice in a given form, special information and issue commands to turn on automatic fire extinguishing installations, turn on the executive settings of systems against smoke protection, process and engineering equipment, and as well as other fire protection devices.
The theme of the work is "System of the security and fire alarm system" (OPS), within which the technical side of the fire alarm system was considered.
Object of study: security and fire alarms.
Subject of study: fire alarm system.
Objectives of the study: the fire alarm system consists in the timely detection, processing and transmission of the received signal about the onset of a fire, violation of access to the premises, the submission of certain commands to the central console.
The scientific and theoretical significance of the study lies in the fact that the material of modern fire and security alarm systems has been analyzed, generalized and systematized.
The practical significance of the work is the development of an educational and methodological complex for studying the fire and security alarm system.
General part of the alarm system
The security alarm system (OS) is a set of interrelated technical means for detecting signs of an intruder being at protected facilities, collecting, processing, transmitting and presenting information to consumers in a given form. The functions of the fire and security alarm system (OPS) include the detection of both penetration and signs of fire at the facility. Technical means (TS) OPS in accordance with GOST 26 342-84 are classified according to two criteria: scope and functionality.
According to the field of application, vehicles are divided into security and security-fire. According to their functional purpose, vehicles are divided into two groups:
a) TC detection (detectors), designed to generate and transmit information about the status of monitored parameters;
b) TS alerts designed to receive, convert, transmit, store, process and display information (notification transmission systems, PPC, annunciators).
A detector is a primary technical means for detecting a change in the environment (intrusion, fire) and formatting a notice: security, fire, or both - security and fire.
A notice in the OPS technique is a message that carries information about the state of a protected object, transmitted using electrical, light and (or) sound signals. Notifications are divided into alarm and service. The alarm notification carries information about penetration or fire. The service notice contains information about arming, disarming, equipment malfunction, etc.
The security alarm loop (AL) is an electrical circuit connecting the output circuits of security detectors, including auxiliary (remote) elements (diodes, resistors) and connecting devices designed to issue notifications of intrusion, fire or malfunction to the control panel. In some cases, power supply to the detectors is provided through the loop.
The control panel (PPK) is used to receive a signal from the detectors, process it and transfer it in a convenient form either to the central console or further to another control panel.
A security and fire alarm is a technical means of an fire alarm system designed to notify people of an intrusion, an attempted intrusion and (or) a fire.
The autonomous security system consists of OPS complexes with access to annunciators and (or) another control panel installed at the autonomous security point.
Autonomous security point (PAS) is a point located at a protected facility or in close proximity to it, serviced by the security service of the facility and equipped with technical means for displaying information about penetration and (or) fire in each of the controlled premises (zones) of the facility for direct perception man.
A notification transmission system (STS) is a set of jointly operating technical means for transmitting via communication channels and receiving at a centralized security point notifications about penetration into protected objects and (or) a fire at them, service and control and diagnostic notifications, as well as for transmitting and receiving telecontrol commands (if there is a reverse channel).
SPI provides for the installation of terminal devices (UO) at facilities, repeaters (R) at ATS cross-countries, in residential buildings and other intermediate points and centralized monitoring consoles (CMS) at centralized security points.
The centralized protection point (CPS) is a dispatching center for the centralized protection of a number of dispersed objects from penetration and fire using the SPI.
Depending on the characteristics of the OO (length, number of rooms, number of storeys, etc.) and the value of the material assets located at the facility, its protection can be implemented through one or more alarm loops. In the event that the security structure of the object includes several loops placed in such a way that when an intruder enters the OO and moves to material values, he needs to overcome several protected zones controlled by various loops with exits to individual monitoring station numbers, security should be considered as multi-line .Thus, a loop or a set of loops that control protected areas on the way of the intruder to the material assets of the OO and have access to a separate monitoring station number is called the signaling boundary ,and the set of protected zones controlled by the signaling boundary is the guard boundary.
Description of the design of the OPS system
The OPS complex for the protection of buildings includes:
a) primary sensors that directly monitor the assigned territory;
b) a controller (control panel) that collects and analyzes sensor readings, as well as controls the entire security system and develops its response to possible emergency situations;
c) a control panel (keyboard) designed to arm and disarm the premises.
There are several types of primary sensors of the alarm system - depending on the specific situation, certain devices can be used, as well as groups of devices that control the same territory according to different parameters. Let's start with the most common ones.
Volumetric infrared motion sensor.
As the name implies, the device controls the change in the thermal field of the room. At the same time, the system setup and the installation location of the sensor must take into account the presence of animals in the house. Cats and small dogs can be ignored at the hardware or software level, but large dog breeds comparable in size to a human on all fours will cause a false positive.
Magnetic contact sensor.
Installed on doors and windows, it reacts to their opening. The device consists of two parts: one of them, equipped with a permanent magnet, is placed on the movable element of the door or window. The second is connected to the corresponding circuit of the controller and is a reed switch soldered into the housing. When both parts of the sensor are aligned, the magnet acts on the reed switch, the circuit is closed. When you try to open the window, the magnet moves away from the reed switch, the circuit opens, and an alarm is sent from the controller. It remains to be added that such devices can be both overhead, that is, fixed on doors and windows from the side of the room, and built-in (hidden), cut into the movable and fixed parts of the structure. In the latter case, access to the sensor elements themselves and the wiring for an intruder is much more difficult.
Mechanical disconnect.
It can be considered a kind of magnetic contact sensor - of course, not by design, but by the principle of operation. A device consisting of a housing with a button is installed on the fixed part of the door or window, and the movable part presses on the sensor button, thereby closing the contact. The rest of the mechanical circuit breaker works similarly to the magnetic contact. By and large, this technology is outdated, but many manufacturers still continue to produce such devices.
acoustic sensor.
It reacts to the sound of breaking window glass, and therefore is installed in close proximity to the window. By itself, this sensor is useless if, for example, an attacker does not break glass, but uses a glass cutter. For this reason, such sensors cannot be the main or the only ones and are used as an addition to other devices.
vibration sensor.
The device is mounted on the wall and captures the vibration at the stage of creating a breach. It is also not recommended for use as the main or sole control sensor. The most widespread scope - protection of especially important rooms.
Smoke sensor.
This device belongs to the fire department of the OPS and reacts to the appearance of smoke in a controlled room. The smoke rises to the ceiling and spreads over its surface, and this is where the smoke sensor is installed. Obviously, it cannot be used, for example, in a garage or kitchen, where the formation of smoke is quite normal, otherwise false alarms of a fire alarm may occur when cooking or warming up a car engine.
Temperature sensor.
Also related to the fire department of the OPS, this sensor is triggered by a significant increase in the temperature in the room, and on condition that it increases for at least 10-30 seconds. The device is used either in tandem with a smoke sensor, or separately - for garages and kitchens.
Technical means of security and fire alarms designed to obtain information about the state of monitored parameters at a protected facility, receive, convert, transmit, store, display this information in the form of sound and light alarms, in accordance with GOST 25 829-78 is classified into two features: scope and functionality.
According to the field of application, vehicles are divided into security, fire and security-fire; according to their functional purpose - to technical means of detection (detectors) designed to obtain information about the state of controlled parameters and notification vehicles, intended for receiving, converting, transmitting, storing, processing and displaying information (SPI, PPC and annunciators).
In accordance with GOST 26342-84, security and fire detectors are classified according to the following parameters.
By appointment: for enclosed spaces, for open areas and perimeters of objects.
By the type of zone controlled by the detector: point, linear, surface, volumetric.
According to the principle of operation, security detectors are divided into: volumetric, magnetic contact, shock contact, piezoelectric, capacitive, ultrasonic, optoelectronic, radio wave, combined.
By the number of detection zones: single-zone, multi-zone.
According to the range of action, ultrasonic, optoelectronic and radio wave security detectors for enclosed spaces are divided into: short range - up to 12 m, medium range - from 12 to 30 m, long range - over 30 m.
According to the range of action, optoelectronic and radio wave security detectors for open areas and perimeters of objects are divided into: short range - up to 50 m, medium range - from 50 to 200 m, long range - over 200 m.
According to their design, ultrasonic, optoelectronic and radio wave security detectors are divided into: single-position transmitter (emitter) and receiver are combined in one block (there may be several transmitters and receivers in one block) two-position transmitter (emitter) and receiver are made in the form of separate blocks, multi-position - more than two blocks in any combination. According to the method of power supply, they are divided into: current-consuming (dry contact is used); powered by AL, from an internal autonomous power source, from an external DC source with a voltage of 12-24 V, from an AC network with a voltage of 220 V; According to the principle of operation, security and fire detectors are divided into: magnetic contact, ultrasonic and optoelectronic. According to the number of detection zones, range and design, security and fire detectors are classified similarly to security detectors.
sensor alarm security protection
Calculation of the placement of sensors in real room conditions
The calculation is carried out according to the tables of the set of rules 5.13130.2009 "Fire protection systems.
The area controlled by one point smoke detector, as well as the maximum distance between the detectors and the detector and the wall, must be determined according to Table 1, but not exceeding the values \u200b\u200bspecified in the technical specifications and passports for the detectors.
Table 1 - Calculation of the placement of smoke fire detectors
Height of the protected premises, m Average area controlled by one detector, m2 Maximum distance between detectors from the detector to the wall Up to 3.5 Up to 859.04.5 St. 3.5 to 6.0 to 708.54.0 St. 6.0 to 10.0 to 658.04.0 St. 10.5 to 12.0 to 557.53.5 Table 2 - Calculation of the placement of thermal fire detectors
Height of the protected premises, m Average area controlled by one detector, m2 Maximum distance between detectors from the detector to the wall Up to 3.5 Up to 255.02.5 St. 3.5 to 6.0 to 204.52.0 St. 6.0 to 9.0 to 154.02.0
The area controlled by one point thermal fire detector, as well as the maximum distance between the detectors and the detector and the wall, will be determined from table 2.
The calculation of the number of fire detectors per area is calculated by the formula: PI \u003d Spom. / hp.p.
Where Spom is the area of the room; hp.p is the average area controlled by one detector.
Organization of the protection of objects with the help of security alarms
Protection of the perimeter of the territory and open areas.
Technical means of perimeter security alarms should be selected depending on the type of perceived threat to the object, interference conditions, terrain, the length and technical strength of the perimeter, the type of fence, the presence of roads along the perimeter, the exclusion zone, its width. The security alarm of the perimeter of the object is designed, as a rule, as a one-line one. To strengthen security, determine the direction of movement of the intruder, block vulnerabilities, multi-line security should be used.
Perimeter security alarm technical means can be placed on the fence, buildings, structures, structures or in the exclusion zone. Security detectors should be installed on walls, special poles or racks, ensuring the absence of oscillations, vibrations.
The perimeter, with the gates and wickets entering it, should be divided into separate protected areas (zones) with their connection by separate alarm loops to the low-capacity control panel or to the internal security console installed at the checkpoint or in a specially designated security room of the facility. The length of the section is determined based on security tactics, technical characteristics of the equipment, the configuration of the external fence, line-of-sight conditions and the terrain, but not more than 200 m for ease of technical operation and prompt response.
The main gate should stand out in an independent section of the perimeter. Spare gates, wickets must enter the section of the perimeter on which they are located. Medium and large-capacity control panels (hubs), SPI, automated notification transmission systems (ASPI) and radio notification transmission systems (RSPI) can be used as internal security consoles. Internal security consoles can operate both with direct round-the-clock duty of personnel on them, and autonomously in the “Self-protection” mode.
Installation of security detectors on the top of the fence should be carried out only if the fence has a height of at least 2 m.
At the checkpoint, in the security room, technical devices for graphic display of the protected perimeter (computer, light panel with a mnemonic diagram of the protected perimeter and other devices) should be installed. All equipment included in the perimeter alarm system must be tamper-proof. Open areas with material assets on the territory of the facility must have a warning fence and be equipped with volumetric, surface or linear detectors of various operating principles.
Protection of the building, premises, individual items
All premises with permanent or temporary storage of material assets, as well as all vulnerable areas of the building (windows, doors, hatches, ventilation shafts, ducts, etc.), through which unauthorized entry into the premises of the facility is possible, should be equipped with technical means of security alarms.
Objects of subgroups A1, A2 and B2 are equipped with a multi-line alarm system, objects of subgroup B1 - single-line.
The first line of the security alarm, depending on the type of alleged threats to the object, is blocked by: wooden entrance doors, loading and unloading hatches, gates - for "opening" and "destruction" ("break"); glazed structures - for "opening" and "destruction" ("breaking") of glass; metal doors, gates - for "opening" and "destruction", walls, ceilings and partitions that do not meet the requirements of this Guiding Document or behind which premises of other owners are located, allowing for hidden work to destroy the wall - for "destruction" ("breach" ), shells of storages of values - for “destruction” (“break”) and “impact”; grilles, blinds and other protective structures installed on the outside of the window opening - for "opening" and "destruction"; ventilation ducts, chimneys, places of input / output of communications with a cross section of more than 200x200 mm - for “destruction” (“break”);
Instead of blocking glazed structures for "destruction", walls, doors and gates for "breach" and "impact", it is allowed, in justified cases, to block these structures only for "penetration" using volumetric, surface or linear detectors of various operating principles . At the same time, it should be borne in mind that the use of passive optoelectronic detectors for this purpose ensures the protection of the premises only from the direct penetration of the intruder.
If it is impossible to block the entrance doors of the openings (vestibules) with technical means of early detection, it is necessary to install security detectors in the doorway between the main and additional doors that detect the intruder's penetration. These detectors should be included in one loop of the door lock burglar alarm. To exclude possible false alarms when the object is armed, the specified alarm loop must be output to the control panel, which has a delay in arming the object.
Detectors that block entrance doors and non-openable windows of the premises should be included in different alarm loops in order to be able to block windows in the daytime when the door security alarm is turned off. Detectors that block entrance doors and openable windows can be included in one alarm loop.
The second frontier of the burglar alarm protects the volume of premises for "penetration" with the help of volumetric detectors of various principles of operation. In large rooms with a complex configuration that require the use of a large number of detectors to protect the entire volume, it is allowed to block only local zones (vestibules between doors, corridors, approaches to valuables and other vulnerabilities)
The third line of the security alarm in the premises is blocked by individual items, safes, metal cabinets, in which valuables are concentrated. The technical means of protection installed in buildings should fit into the interior of the premises and, if possible, be installed hidden or masked.
In different areas, it is necessary to use security detectors operating on different physical principles of operation. The main types of detectors that protect the premises of the object and its structures from the alleged method of criminal influence.
The number of burglar alarm loops should be determined by security tactics, the size of buildings, structures, structures, number of storeys, the number of vulnerabilities, as well as the accuracy of localization of the penetration site for prompt response to alarms.
The perimeter of a protected building, as a rule, should be divided into protected zones (facade, rear, sides of the building, central entrance and other areas) with their allocation into independent alarm loops and the issuance of separate signals to the control panel or the internal security console of the facility.
To enhance security and increase its reliability, additional detectors - traps should be installed at the facilities. Trap signals are output via independent or, in the absence of technical feasibility, via existing security alarm loops. Each room of subgroups A1 and A2 must be equipped with independent security alarm loops. The premises of subgroups B1 and B2, assigned to one financially responsible person, owner or combined for any other reason, should also be equipped with independent security alarm loops, and, for ease of operation, no more than five adjacent rooms located on the same floor should be blocked with one loop .
In premises where personnel must be around the clock, separate sections of the perimeter of the premises, as well as safes and metal cabinets for storing valuables and documents, should be equipped with a burglar alarm.
Organization of the transmission of information about the alarm. The transfer of notifications about the operation of the security alarm from the object to the ARC can be carried out from the small-capacity control panel, the internal security console or terminal devices.
The number of security alarm lines displayed on the ARC by separate numbers is determined by a joint decision of the management of the facility and the private security unit based on the category of the facility, risk analysis and potential threats to the facility, the possibilities of integrating and documenting the control panel (internal security console or terminal device) of incoming information, as well as the procedure for organizing the duty of security personnel at the facility.
The minimum required number of security alarm lines displayed on the ARC from the entire protected facility should be for a subgroup.
B1 - one united frontier (the first is the perimeter); BII - two combined frontiers (the first is the perimeter and the second is the volume) *.
In addition, if there are special premises at the facility (subgroup A2, safes, weapons rooms and other premises requiring increased security measures), the boundaries of the security alarm of these premises are also subject to the ARC.
If there is an internal security console at the facility with round-the-clock duty of its own security service or a private security company, the ARC displays: one common signal that unites all the boundaries of the security alarm of the facility, with the exception of the boundaries of special premises of the facility; security alarm boundaries (perimeter and volume) of special premises. At the same time, registration of all incoming information from each security line of premises on the internal security console should be ensured.
If there is an internal security console at the facility with round-the-clock duty of private security officers (Micro-PCO), all the boundaries of the security alarm of all premises of the facility (including special rooms) are connected to the internal security console, which provides automatic registration of all incoming information, and one general signal to the ARC.
At facilities where only special premises are guarded, all security alarm lines of these premises are subject to output to the PSC.
When protecting only individual devices (ATMs, gaming machines, distribution cabinets and other similar devices), one line of the security alarm is displayed on the ARC (blocking for "destruction" and "opening").
If there is no technical possibility at the protected facility to fulfill the requirements, the issues of removing the boundaries of the security alarm are decided by the private security unit in each specific case. The boundaries of the burglar alarm must be displayed on the ARC from the internal security console, control panel or terminal device, which ensures that the alarm condition is memorized and fixed on a remote light (sound) annunciator or indicator. For objects of the residential sector, it is allowed to use terminal devices and object blocks without corresponding storage of the alarm state and its fixation.
Notifications from the alarm loops are output by one combined signal to the ARC and / or to the duty department of the internal affairs bodies directly or through the control panel, the SPI terminal device, the internal security console.
Security and alarm notifications can be transmitted to the ARC via specially laid communication lines, free or switched telephone lines for the period of protection, a radio channel, busy telephone lines using compaction equipment or informant SPI via a dial-up telephone connection (“auto-dialing” method) with mandatory channel control between the protected object and ARC. From protected objects, "auto redial" should be carried out by two or more telephone numbers.
In order to exclude access of unauthorized persons to detectors, control panels, splitting boxes, and other security equipment installed at the facility, measures must be taken to mask and covertly install them. The covers of the terminal blocks of these devices must be sealed (sealed) by an electrician of the security guard or an engineering and technical worker of the private security unit indicating the name and date in the technical documentation of the facility.
Distribution cabinets intended for crossing alarm loops must be lockable, sealed and have blocking (anti-tamper) buttons connected to individual numbers of the internal security console “without the right to turn off”, and in the absence of an internal security console - to the ARC as part of the alarm system .
Safety during installation and operation of the product
When connecting, installing and operating devices that are part of the fire alarm system, you must be guided by the "Rules for the technical operation of consumer electrical installations" and "Safety regulations for the operation of consumer electrical installations".
Persons who have studied this manual, as well as those who have passed safety attestation for the 3rd group of admission during the operation of electrical installations, have been instructed in safety at the workplace, are allowed to work with the System.
Carrying out all work on connection and installation of the System devices does not require the use of special protective equipment.
It is not allowed to use abrasive and chemically active substances when cleaning contaminated surfaces.
It is forbidden to install the System devices on current-carrying surfaces and in damp rooms (with humidity above 80%).
It is recommended to install the System devices in the places most suitable for their functional purpose and meeting additional requirements (for example, ensuring the confidentiality of the information entered, exclusion of unauthorized access by unauthorized persons, etc.), while their maintenance should not be hindered. Before connecting the System devices, it is necessary to study the technical characteristics, principles of operation and connection features of these devices.
a) When connecting the equipment, it is necessary to strictly observe the polarity of the connection of the System devices.
b) The choice of wires and cables, methods of their laying should be made in accordance with the requirements of SNiP 3.05.06-85
c) When connecting the connecting wires to the terminals of the devices, do not use excessive force when tightening the screws in order to avoid the failure of the terminals.
d) When setting the hardware addresses of devices that have DIP switches for this purpose, do not use excessive force when changing the position of the switches in order to avoid their failure.
e) In order to avoid failure of the units that provide communication between the System devices via the RS-485 protocol, when several devices are powered from different sources, the negative power leads of these devices must be combined.
Installation and adjustment work should be started only after the implementation of safety measures in accordance with SNiP III-4-80.
During installation, transportation, storage, decommissioning and disposal of radioisotope fire detectors, the requirements of the Basic Sanitary Rules for Working with Radioactive Substances and Other Sources of Ionizing Radiation OSP-72/87 must be met.
When working with hand power tools, it is necessary to comply with the requirements of GOST 12.2.013-87.
When working with adhesives, precautions and safety rules should be observed in accordance with the requirements of GOST 12.1.007-76.
In this chapter, safety precautions were considered during the operation of the alarm system. On the basis of the chapter, the following conclusions can be drawn: if the operating conditions of the alarm systems are properly observed, there is no particular threat to life and health, the percentage of injuries is reduced to a minimum.
Conclusion
Thus, to sum up, we come to the following conclusion - technical means of security and fire alarm systems designed to obtain information about the state of controlled parameters at a protected facility, receive, convert, transmit, store, display this information in the form of sound and light alarms.
In this graduation project, the main devices of the fire alarm system were considered, a scheme of the fire alarm system was developed for a training stand in fire safety engineering.
The existing alarm systems and their characteristics, as well as the characteristics of sensors and structures of the alarm system, methods of installation and commissioning of the alarm system are considered.
Measures have been developed to ensure safe working conditions and requirements for the operation of the OPS system.
List of used literature
1. GOST 12.1 004 - 91 SSBT. Fire safety. General requirements.
Korolev S.G. Rules for the installation of electrical installations. Energoatomizdat.-M.: Ekskmo, 2008.-256 p.
Ordinary F.A. Security and fire alarm systems. - St. Petersburg: Peter, 2002.- 360s.
Sinilov V.G. Security, fire and fire alarm systems: textbook. for the beginning prof. education. - M.: IRPO; ProfObrIzdat, 2001.-267 p.
Starshinov B.P. Fire safety systems - M .: Moscow Publishing House, 2003.-164 p.
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Objective: study of the principle of operation of the automatic fire fighting system
alarms. Familiarity with the principles of operation of fire heat and smoke detectors.
General instructions
The widespread use of oil and gas motor fuels, flammable liquids and gases in road transport under certain conditions can cause a fire, which is associated with large material losses and death of people. Early automatic detection of a small fire source by a fire detector allows you to take the necessary measures in a timely manner and eliminate the fire source at the initial stage of its development.
The domestic industry produces automatic fire detection devices - fire detectors of various types of action, photoelectric and ionization - for detecting smoke; thermistor, thermomagnetic, thermoelectric, heat-melting, reacting to excess temperature. photoelectric and ultrasonic - to detect an open flame and turbulent heat flows that occur above the fire. Signals from fire detectors are received by on-site devices, concentrators, control panels, which can be installed at a considerable distance from protected objects
Set of fire detectors. object devices, concentrators and receiving panels, interconnected in an appropriate way, constitutes an automatic fire alarm system.
heat detectors, reacting to excess temperature of the environment, depending on the physical phenomenon underlying the operation of the detector, are divided into several types. The phenomena of changes in the electrical conductivity of solids, contact potential difference, ferromagnetic properties of materials, changes in the linear dimensions of solids, etc. are widely used. Heat detectors of maximum action are triggered at a certain maximum temperature. Detectors that respond to the rate of temperature increase are called differential.
Often, a ferromagnetic material is used as a sensitive thermoelement in fire detectors. The physical and technical basis of such detectors is the loss of the magnetic properties of the magnetic insert upon reaching a controlled temperature threshold close to the Curie point.
The disappearance of the magnetic properties of ferrites at a temperature at the Curie point is explained by the fact. that the energy of thermal motion becomes greater than the energy of the orienting internal molecular field. When the temperature of the magnetic material decreases below the Curie point, its magnetic properties are restored.
In ferrites of various compositions, the Curie point temperature has a different value. So, nickel-zinc ferrites have a temperature Curie point in the range of 70...90°C.
The thermal magnetic fire detector PP105-2/1 (Fig. 1, a) is designed for indoor operation and installation at stationary facilities in order to detect a fire and generate an alarm signal to control panels and fire alarm devices.
The detector consists of a base 1 with terminals 6 for connecting the wires of the fire alarm loop and a temperature-sensitive element 3 mounted on two racks 5 with heat sinks 4, closed with an easily removable protective cap 2.
The temperature-sensitive element of the detector (Fig. 1b) is a non-separable unit consisting of a temperature-sensitive magnetic system in the form of two ring permanent magnets 7 with a temperature-sensitive ferrite 9 installed between them with a low-temperature Curie point (near 70°C). The heat-sensitive ferrite magnetic circuit and both ring magnets are fixed with a special glue on the bulb of the magnetically controlled contact (reed switch) 8. At temperatures below the threshold temperature of the detector, the reed switch contacts are closed under the action of the longitudinal magnetic field of the thermoelement magnetic system. Under the influence of elevated temperature, perceived by thermal receivers, exceeding the Curie point for the ferromagnetic material from which the detector's heat-sensitive ferrite is made, the magnetic permeability of the ferrite practically drops to zero. This leads to a sharp decrease in the longitudinal field that previously held the reed switch contacts in the closed state, as a result of which the contacts open, signaling an increase in temperature at the detector installation site above 70 ° C.
Technical characteristics of the detector IP105-2/1: Response temperature.°C……………………………….……………………….. 70 ± 7
Transient electrical resistance of closed contacts, Ohm, not more than…….0.5
Operation inertia, s, not more than ……………………………………………..120
Protected area, m 2 ……………………………………………………………….. 15
Operating temperature range, °C …………..……………………………………..… ±50
The maximum allowable current flowing through the contacts for a long time, mA….…. ten
Average service life, years…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
Thermal fire detector IP104-1 is designed to issue an alarm when the air temperature rises above the established norm to the object control panel, electrical fire alarm station or centralized alarm control panel.
The detector IP 104-1 is used in closed explosion-proof rooms, as well as in explosive rooms with devices that provide intrinsically safe operating conditions.
The detector (Fig. 2) consists of a body 4, a thermal lock 5 and a base 1. The contacts of the thermal lock are soldered with Wood's alloy. Screws 3 and nuts 2 with washers are designed to fix the thermal lock inside the housing, as well as to connect to the alarm circuit.
When the ambient temperature in the protected room rises above 72 ° C, the Wood alloy junction melts and the contacts of the thermal lock open (break the electrical circuit).
A break in the electrical circuit is a signal that the temperature has risen above the permissible level.
Technical characteristics of the detector IP104-1:
Response temperature, °С ……….72 ±2
Transient electrical resistance of closed contacts, Ohm .......................... 0.1
response inertia,
s, no more…………………………….…125
Protected area, m 2 ……………….15
Operating temperature range, °С….….±50
A, no more……………………………….0.1
Average service life, years…..………….10
With the simultaneous use of fire detectors in the electrical signaling line with burglar alarm devices, a diode D226B is installed inside the housing parallel to the break contacts.
The DIP-1 detector is designed to detect fires accompanied by
the appearance of smoke or an increase in temperature in enclosed spaces. The fire detection signal is sent to the control panel by opening normally closed relay contacts. At the same time, the red indicator light on the detector turns on. The device is designed to work together with any object receiving and control device.
Technical characteristics of the detector DIP-1
Response temperature. °C……………………………………………………..…….90
Inertia response when increasing
optical density of the medium up to 10%, s…………………………………………………..5
Permissible background illumination at the location of the detector installation. lux, no more……..10000
DC supply voltage, V………………………………………….……24 ± 2.4
Power consumption in standby mode, W. No more ………..………………. ..one
Same in alarm transmission mode……………….……………………………..2
Protected area, m 2 ……………………………………………….……………….85
Operating temperature range, С…………………………………………………… ….-30…-50 Relative air humidity at a temperature of 35 С. %, no more…..…..… …………98 Average service life, years …..……………….……………………………………….10
The detector is a combined thermophotoelectric device that gives an alarm when smoke appears or the temperature rises at the place of its installation.
Housing 3 (Fig. 3) of the DIP-1 detector has a protective grid 7, inside which there is a smoke-sensitive area 1 formed by the intersection of the solid angles of the field of view of the radiation source 2 and the photodetector 6 not directly illuminated by it, which are fixed in the optical channels 4 of the holder 5 When smoke appears, it freely penetrates through the protective grid 7 and enters the sensitive area 1. In this case, the radiation of the source 2 is reflected from the smoke particles and affects the photodetector 6, the electrical signal of which, passing through the processing device, causes an alarm.
The design of the detectors allows you to securely mount them on reinforced concrete panels, wooden or metal structures. It is recommended to place the detectors on the ceilings of the rooms to be saved; it is also possible to install them on vertical surfaces at a distance of no more than 0.5 m from the ceiling.
The device of the receiving and control fire and security alarm "Signal-37Yu" is designed to monitor the state of the security and fire alarm loop of enclosed spaces and issue control signals for sound and light annunciators, alarms to the centralized monitoring console (CMS).
Technical specifications
Rated supply voltage…..………………………………….……………… 220 V
AC frequency ……………….…………………………………….………50±1 Hz
Supply voltage deviation
from the nominal value, not more than ………………………………………….. …. -fifteen%
Number of connected alarm loops ……………….…………….. 1
Insulation resistance of the alarm loop, not less than……………………………20 kOhm
Alarm loop resistance without taking into account the remote
resistor, no more………………………………………………………………………. 1.0 kΩ
Power consumed by the device, not more than………………………………………….10 VA
Alarm light power,
connected to the device, not more than……………………………………………..……... 25 VA
The power of the alarm sounder,
connected to the device, not more than………………………………………..…………………25 VA.
Annunciator operation mode:
continuously flashing light (in alarm mode);
short-term sound (in alarm mode);
continuous light at full heat (in standby mode);
the light annunciator is not lit (when the alarm loop is open before the object is armed).
In the event of a break, short circuit, increase in the resistance of the alarm loop above 30 kOhm, the device generates alarm signals: flashing light, single sound, continuous to the centralized monitoring console.
Relative humidity ………………………………………………30..80%
Time of continuous operation of the device, not less than …………………………………..170 h
Belarusian National Technical University
INSTRUMENT-MAKING FACULTY
Department of "Information-measuring equipment and technologies"
INSTRUCTIONS
To the implementation of laboratory work No. 2
on the topic: "Research of schemes for indicating and monitoring the state of direct current loops in devices of fire and security alarm systems"
by discipline: " Nodes of devices of security systems».
Minsk 2014
Purpose and tasks of the work.
1.1 Purpose of work:
The study of typical schemes for indicating and monitoring the state of direct current loops in fire and security alarm devices, measuring the main parameters and methods of coordination with communication channels.
1.2 Work tasks:
Assimilate the necessary array of data on the indication and control circuits of loops. Get practical skills in carrying out commissioning work with loops at the facility.
1.3 Preparation for work:
Study the theoretical part. Study the technical descriptions and operating instructions of the recommended fire and security alarm devices regarding work on the loops. Familiarize yourself with your assignment. Answer security questions.
2 Theoretical part.
2.1 Loops of security and fire alarms
1.1 Alarm loop
- a circuit (electrical, i.e. wired, or wireless: radio channel, fiber optic or other), connecting the output nodes of the detectors (sensors), including auxiliary (remote) passive elements (resistors, diodes, capacitors, etc.) and connecting lines and designed to transmit information from the detectors about the parameters controlled by them to the receiving control device (PPK), and in some cases to supply power to the detectors (usually via a two-wire line).
Types of loops (according to the accuracy of the sensor operation):
- conventional (detectors do not have their own address, i.e. the accuracy of the trigger point is within the loop);
- quasi-address (operation accuracy - up to the zone (1/2) of the loop, i.e. from 1 to several detectors);
- addressable (with an addressable analog or digital bus for data exchange between the control panel and detectors, here the accuracy of the trigger point is a specific detector).
Types of loops (according to the ability to recover):
- non-recoverable (i.e. even with a single triggering of a sensor located in such a loop, the latter itself is not restored. At the same time, on all OPTS devices, all serviceable loops are restored if the device is briefly disarmed and re-armed (ideally remotely, via communication channel, for example, from a cell phone, in extreme cases, the Client must return to the object and retake it in the same way (with a TM key, magnetic card, from the keyboard) - this is very inconvenient, especially at night or on weekends);
- self-restoring (available in modern OPTS devices: after each sensor triggering, they are armed again, but if the sensor starts to constantly trigger (for example, a volume sensor), then a notification of each such alarm will be transmitted to the remote control, which is unacceptable);
- self-switching off (with multiple triggering of sensors in the loop in a given time interval, for example, more than 1 time in 10 minutes and six triggers in 1 hour - the device turns off such a loop).
1.2 Burglar alarm line
- a loop or a set of alarm loops that control the protected areas of a territory, building or premises (perimeter, volume or area, the valuables themselves and / or approaches to them) on the path of the possible movement of the intruder to material values, upon overcoming which a corresponding intrusion notification is issued. Many objects have 1 line of protection (external perimeter), and those with zones of accumulation of valuables - 2 lines (the 2nd line is usually internal). If window openings have shutters, then it is reasonable to allocate a separate line (preliminary protection) on them, the loops of which transmit alarm signals from detectors (sensors) installed on the shutters or next to them in case of unauthorized opening of the shutters.
1.3 Guard zone
- this is a part of the protected object, controlled by one or more alarm loops. May be crossed by one or two security lines.
Types of protected areas:
1) entry/exit zones or zones with or without delay (on entry/exit);
2) zones of immediate reaction;
3) passage zones (each is guarded by two loops);
4) round-the-clock security zones (fire, alarm, etc.);
5) day observation zones;
6) zones excluded from protection.
1.4 Reception and control device (PPK), or bad namecontrol panel
- this is a technical means of OPTS (fire and alarm) alarm systems for receiving messages from detectors (sensors) included in alarm loops, or other control panels, converting signals, issuing notifications and turning on sirens, and in some cases for powering security detectors.
PPK operating modes:
1) security
(the device monitors the state of the loops and itself, and the violation of the loops leads to the formation of alarms);
1.1) full guard(when the device controls the state of all loops and itself);
1.2) partial protection(with control of part of the loops: usually fire and alarm and the device itself), with group exclusion of a pre-programmed group of loops (common for this mode), or selective exclusion of loops (determined individually in each specific case). This mode is usually used in two cases:
1.2.1) to arm the alarm system when people remain at the facility (for example, guarding the house at night);
1.2.2) arming a system with faulty loops.
2) disarmed
(standby mode).
1.5 Types of control panel (according to the method of connecting loops)
:
1) with plumes of a radial structure.
In this case, each loop is connected directly to the control panel. Such a structure justifies itself with a small number of loops (usually up to 16) and at facilities that do not require the organization of remote loops. It is usually used for small and medium objects.
2) with a tree-like structure of loops.
Such control panels have a special information bus (or even several buses) of 2/4 wires, and expanders are connected to this bus. In turn, radial loops are connected to the expanders. Several basic radial loops can also be connected to the control panel itself. The total number of loops is usually = 24-128. The expander controls the status of the loops, encodes information about their status and transmits via the information bus to the control panel, which has a module for indicating the status of all loops. Used for OPS systems of medium-sized objects. Obviously, in such systems, the security of the data bus is important, since its damage can disable a significant part of the system.
3) with linear structure loops and addressable detectors.
Such control panels have two or four two-wire loops to which up to 32 addressable detectors are connected. The length of such a train is from 800 to 1200 m.
2 Basic methods for monitoring the signaling loop
The alarm loop (AL) is one of the necessary components of the on-site fire and security alarm system. It is a wire line that electrically connects the remote element (elements), the output circuits of security, fire and security fire detectors with the input of the control panel.
Sometimes the old names of the alarm loop are used: a beam, an alarm circuit, a blocking line, a blocking loop, etc. In the modern interpretation, a fire and security alarm loop is an electrical circuit designed to transmit alarm and service notifications from detectors to the control panel, as well as (if necessary) to supply power to the detectors. The alarm loop, as a rule, is two-wire and includes remote (auxiliary) elements installed at the end of the electrical circuit. They are sometimes referred to as signaling loop load elements (load).
The points of electrical connections of the alarm loop, as well as the contacts for connecting detectors during operation, are exposed to prolonged exposure to high humidity in a wide temperature range, and in some cases to aggressive environments. It is known that the contact resistance Rk is the sum of the contraction resistance and the resistance of thin surface films that cover the contacted surfaces. Corrosion, adhesion, and adsorption processes lead to the appearance of such films. Rk is affected by the contact material and the nature of its processing (contact shape, hardness), contact pressing force, as well as the thickness and type of the film covering the contacts. For contacts made of base metals (and even silver), the latter factor is often the determining factor in choosing the operating conditions and parameters of switched electrical circuits. Significant impact on Rk renders also an electric mode of operation of contacts. Due to the phenomenon of fritting, at certain source power and voltage at the contacts, the resistance of the film may partially or completely disappear.
If the initial value of the contact resistance of clean contacts is almost independent of the current 7^, then after exposure to aging factors (operation in unfavorable conditions) it increases sharply.
At low currents in the alarm loop (less than 1 mA), the transition resistance can be significant. In this case, the loop resistance is unstable and can vary over a wide range within a short period of time. With increasing current, the resistance of the contacts decreases, but even at significant currents, it does not recover to its original value. A sharp change in contact resistance corresponds to fritting.
Relative stabilization of the alarm loop parameters during its operation in adverse conditions can be achieved by using an increased voltage in the loop - at least 15 ... 20 V (the upper value is limited by safety requirements) and an increased current - at least 5 ... 10 mA. The form of current and voltage can be different, since only their amplitude values are important for the formation of an electrical contact. In practice, an operating voltage of 12 V and a current in the range of 1 ... 5 mA are used.
Thus, to ensure reliable operation of the device in a wide range of operating conditions, the optimal electrical mode of operation of the alarm loop must be provided. The device must be protected from electromagnetic interference, as well as from high voltage pulses in the alarm loop. A modern requirement for the device is also the possibility of power supply and its joint operation via an alarm loop with current-consuming security and active fire detectors.
The fulfillment of the above requirements for the device is largely determined by the method used in it for monitoring the signaling loop. The distinguishing features of the control method used are the composition and type of load radioelements of the signaling loop and the power supply circuit of the loop.
At present, typical fire and security alarm devices mainly use alarm loop control schemes:
with power supply of the alarm loop with direct current and a resistor used as an external element;
with power supply of the alarm loop with alternating pulsed voltage and series-connected resistor and semiconductor diode used as a load;
with power supply of the alarm loop with pulsating voltage and a capacitor used as a remote element.
experimental part
Figure 1. Structural diagram of the block of control and indication of loops.
Where: MK - microcontroller; T1 - single vibrator; T2 - generator of rectangular pulses;
RLZ - adjustable delay line; MP - multiplexer; BK - block of comparators;
LU - logical device; STZ - current mirror circuit; BP - power supply;
Osc. – oscilloscope type C1-65.
Figure 1 shows a block diagram of a laboratory installation for studying a typical circuit for indicating and monitoring loops in fire and security alarm devices. The principle of operation of the installation is based on the requirements of GOSTs and governing documents regarding the time parameters for determining the state of the alarm loop.
The microcontroller of the receiving and control device (PKP) generates once every 8 seconds a request pulse for the circuit for monitoring the state of the loops. The number of impulses received by the multiplexer is equal to the number of alarm loops in the control panel.
The circuit for monitoring the status of loops within 10 ms generates a nibble of the state of each loop on the MC buses. The amount of data depends on the number of loops in the device.
Figure 2 Electrical diagram of the multiplexer switching pulse shaper.
Lab assignment
4.1 Assemble the scheme of the laboratory installation in accordance with Figure 1 and connect the load (loops);
4.2 In accordance with the task in table 1, choose your option, study the circuit and the instruction manual for the IC NE556N (Figure 2), calculate the required values and types of resistors and capacitors for the multiplexer switching pulse shaper circuit.
(Т2 = Т1/2N; Where: N is the number of loops according to the task)
4.3 According to the directories, select the types and ratings of resistors and capacitors.
4.4 Record the obtained calculation data in the final table for your version.
TABLE 1
| var. no. tasks | Control panel type | Number of loops | R1, Ohm | R2, Ohm | R3, Ohm | С1,uF | C4, uF | Т1,ms |
| Alarm -3 | 0,5 | |||||||
| Alarm - 3 | ||||||||
| Alarm - 4 | 1,5 | |||||||
| Alarm - 5 | ||||||||
| Alarm - 5 | 2,5 | |||||||
| Alarm - 5 | ||||||||
| Alarm - 5 | 3,5 | |||||||
| Alarm - 7 | ||||||||
| Alarm - 7 | 4,5 | |||||||
| Alarm - 7 | ||||||||
| Alarm - 7 | 5,5 | |||||||
| Alarm - 7 | ||||||||
| Alarm - 7 | 6,5 | |||||||
| Alarm - 7 | ||||||||
| Alarm - 7 | 7,5 |
5 Security questions
- Types of security and fire alarm loops;
- Two-wire current loop, characteristic, main parameters;
- Ways to control and register events in alarm loops;
- Leakage currents in the loop. The amount of resistance between the wires in the loop;
- Burglar alarm line;
- Security alarm zone;
- Informativeness of the loop;
- Power supply for detectors connected to the loop;
- Appointment of a tamper loop;
- Appointment of the terminating resistor in the loop;
- Loop resistance limits;
- The number of loops in the control panel and options for analyzing their state.
4.1 Title page;
4.2 Goals and objectives of laboratory work;
4.3 Diagram of the laboratory setup;
4.4 Schematic diagram of electrical connection of IC NE556N in accordance with the task;
4.5 Table of calculations and measurements;
4.6 Answer to the security question in accordance with the task option;
Laboratory work on the topic: Modern office and building security and fire alarms: purpose, description, classification and characteristics of the alarm
As a rule, fire and security alarms are integrated into a complex that combines security systems and engineering systems of a building, providing reliable address information for access control, warning, fire extinguishing, smoke removal systems, etc.
The structure of the fire and security alarm
Depending on the scale of the tasks that the security and fire alarm system solves, it includes equipment of three main categories:
equipment for centralized control of fire and security alarms (for example, a central computer with software installed on it for managing fire and security alarms; in small fire and security alarm systems, centralized control tasks are performed by the security and fire panel);
equipment for collecting and processing information from sensors of the security and fire alarm: control devices for security and fire (panels);
sensor devices - sensors and announcers of the security and fire alarm system.
The integration of security and fire alarms as part of a unified security and fire alarm system is carried out at the level of centralized monitoring and control. At the same time, the security and fire alarm systems are administered by control posts independent of each other, maintaining autonomy as part of the fire and security alarm system. At small facilities, fire and security alarms are controlled by control panels.
The control panel supplies power to security and fire detectors via the security and fire alarm loops, receives alarm notifications from the detectors, generates alarm messages, and also transmits them to the centralized monitoring station and generates alarm signals for triggering other systems.
The security alarm system as part of the security and fire alarm system performs the tasks of timely notification of the security service about the fact of unauthorized entry or attempted entry of people into the building or its individual premises, fixing the date, place and time of violation of the security line.
The fire alarm system is designed for timely detection of a fire and the generation of control signals for fire alarm systems and automatic fire extinguishing.
Domestic regulatory documents on fire safety strictly regulate the list of buildings and structures to be equipped with automatic fire alarms. Currently, the entire list of organizational and technical measures at the facility during a fire has one main goal - saving people's lives. Therefore, the tasks of early fire detection and alerting personnel come to the fore. The solution of these problems is assigned to the fire alarm, the main functions of which are formulated in the following definition.
Fire alarm (according to GOST 26342-84) - receipt, processing, transmission and presentation in a given form to consumers using technical means of information about a fire at protected facilities.
The main functions of the fire alarm system are provided by various technical means. Detectors are used to detect a fire, for processing and logging information and generating control alarms - receiving and control equipment and peripheral devices.
In addition to these functions, fire alarms should generate commands to turn on automatic fire extinguishing and smoke removal systems, fire alarm systems, technological, electrical and other engineering equipment of facilities. Modern fire and security alarm equipment has its own advanced warning function. Despite the fact that fire warning systems are singled out as an independent class of equipment, on the basis of fire alarm technical means of quite a few manufacturers, it is possible to implement warning systems of categories 1 and 2 (according to NPB 104-03).
Fire alarm detectors
To obtain information about the alarm situation at the facility, the fire and security alarm system includes detectors that differ from each other in the type of controlled physical parameter, the principle of operation of the sensitive element, and the method of transmitting information to the central alarm control panel.
According to the principle of generating an information signal about penetration into an object or a fire, fire alarm detectors are divided into active and passive.
Active fire and security alarm detectors generate a signal in the protected area and respond to changes in its parameters.
Passive detectors respond to changes in environmental parameters caused by an intruder or fire.
Depending on the methods of detecting alarms and generating signals, detectors and fire alarm systems are divided into conventional, addressable and addressable analog.
In non-address systems, detectors have a fixed sensitivity threshold, while a group of detectors is included in a common fire and security alarm loop, in which, in the event that one of the fire and security alarm devices is triggered, a generalized alarm signal is generated.
Address systems are distinguished by the presence in the notification of information about the address of the fire alarm device, which allows you to determine the fire zone with an accuracy of the location of the detector.
The address-analogue security and fire alarm system is the most informative and developed. In such a system, “intelligent” fire and security alarm detectors are used, in which the current values of the controlled parameter, together with the address, are transmitted by the device via the security and fire alarm loop. This monitoring method is used for early detection of an alarm situation, obtaining data on the need for maintenance of devices due to pollution or other factors. In addition, analog addressable systems allow, without interrupting the operation of the fire and security alarm, to programmatically change the fixed sensitivity threshold of the detectors if it is necessary to adapt them to the operating conditions at the facility.
Each type of detector has its own list of basic technical characteristics determined by the relevant standards. At the same time, even detectors of the same type have differences in the design features of their components, ease of use, reliability, design level, which is taken into account when choosing a particular device or manufacturer.
Reception and control equipment for fire and security alarms
To receive and process notifications, the security and fire alarm system uses various types of receiving and control equipment: central stations, control panels, receiving and control devices (the name is determined by the standards of the country of origin, hereinafter we will use the term "control panel"). This equipment is distinguished by information capacity - the number of controlled alarm loops and the degree of development of control and notification functions. There are control panels for fire and security alarms for small, medium and large objects. As a rule, small objects are equipped with conventional systems that control several loops of the security and fire alarm, and at medium and large objects, addressable and addressable analog systems are used.
A distinctive design feature of the addressable and addressable-analogue fire and security alarms is the use of a ring alarm loop, which has increased protection against violation of communication lines with detectors. As a rule, the ring loop of control panels from different manufacturers is hardware compatible with detectors developed by the same companies. Some control panels support multiple loop topology options, making it easier to design a fire alarm on site.
For compatibility of addressable or addressable-analogue fire and security alarms with non-address detectors (including those of other manufacturers), control panels can additionally support control of non-addressed security and fire alarm loops.
fire burglar alarm detector
Control and notification functions are implemented in control panels using specialized input and output interfaces. To display information, the security and fire alarm system widely uses built-in light and alphanumeric indicators, sound signaling devices. The output interface in fire alarm control panels for small facilities is usually a set of relay outputs. At large facilities, fire and security alarm systems are built using network technologies, so fire control panels are equipped with external RS422 or RS48 interfaces, and are also capable of interacting via Ethernet or using a dial-up modem connection. Structurally, interface nodes can be included in the control panel (located on a common printed circuit board). A more preferable option is their implementation in the form of separate printed circuit boards, mounted, if necessary, inside the control panel housing.
Peripheral devices for fire and security alarms
Peripheral devices are considered to be all fire and security alarm devices (except detectors) that have an independent design and are connected to the fire and security alarm control panel via external communication lines. The following types of fire alarm peripherals are most commonly used:
control panel - used to control fire and security alarm devices from a local point of the object;
short circuit isolation module - used in fire and security alarm loops to ensure their operability in case of a short circuit;
non-address line connection module - for control of non-address fire alarm detectors;
input / output module - for monitoring and controlling external devices (for example, automatic fire extinguishing and smoke removal installations, technological, electrical and other engineering equipment);
sound annunciator - for notification of a fire or alarm at the required point of the object using an audible alarm;
light annunciator - for notification of a fire or alarm at the required point of the object using light signaling;
message printer - for printing alarm and service system messages.
Integration of fire and security alarms with integrated building security systems
When installed at large facilities, to ensure the required level of building security, the fire alarm system is integrated with other security and life support systems of the facility. This is necessary for a quick response to a message about a fire or an alarm received from the sensors of the security and fire alarm systems, and to provide optimal conditions for eliminating the emergency situation that has arisen. For example, in response to a fire message generated by a fire and security alarm, the following actions are performed in the alarm zone:
Turn off ventilation.
Switching on the smoke exhaust system.
Shutdown of power supply (except for special equipment).
Conclusion from the disturbing zone of elevators.
Turning on emergency lighting and light indication of ways and exits for evacuation of people.
Unblocking emergency exits on evacuation routes.
Turn on the notification system with information for the alarm zone.
Thus, the security and fire alarm becomes part of the overall security system, while not only the issues of general monitoring from the main guard post, but also the interaction of all subsystems are solved. In the latter case, one of the most important requirements for the fire and security alarm system must be met - the possibility of its integration into the overall security system. Integration may be required both at the simplest (relay) level and at the software level, when compatibility of data exchange protocols in information buses and communication lines of various subsystems is necessary. An important role in this is played by the support of one or more network technologies from the security and fire alarm equipment: Ethernet, Arcnet, Lonwork, Internet, etc.
Power supply for fire alarm devices
All fire and security alarm devices must be provided with uninterrupted power supply. As a rule, the mains power supply of the control panels of the fire and security alarm is used as the main one, the rest of the devices are powered by low-voltage secondary DC sources or from the security and fire alarm loop. In accordance with domestic fire safety standards, the fire alarm system must function uninterruptedly in the event of a power failure at the facility during the day in standby mode and at least 3 hours in alarm mode. To fulfill this requirement, the fire alarm system must use a backup power supply system - additional sources or built-in batteries.
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