The automatic fire alarm system is designed to detect the source of fire and promptly respond to this event.
In accordance with a given algorithm, it collects and processes data on key parameters and displays a fire alarm to the security post (central control room), and also generates an evacuation alert.
Automatic fire alarm, regardless of its scale and range of tasks, minimally includes the following types of devices:
- sensors (detectors) – sensitive detectors that detect a possible fire by analyzing environmental factors (smoke, temperature, etc.);
- receiving and control device - a device that collects and processes information received from detectors;
- sound and light alarms (sirens, displays, lamps).
In addition, automatic systems can use centralized monitoring and control devices. For small objects, they represent a simple control panel from which a limited number of commands are given.
Larger fire alarm systems can be controlled from a PC with dedicated software installed. As a rule, this applies to fire and security systems, where the computer performs the functions of data storage and processing of statistical information.
FIRE DETECTORS
Devices that monitor the situation at a protected facility, monitoring a number of parameters characteristic of the occurrence of a fire: temperature, smoke, source infrared radiation etc. They differ from each other in many parameters:
- detection principle;
- method of transmitting a signal to a receiving and control device;
- type of tracking of the controlled parameter (threshold, differential or combined).
Active detectors monitor the parameters of the infrared beam emitted by them and include an emitter and a receiver.
RECEIPT AND CONTROL DEVICES
The main differences between equipment of this type are its information capacity, that is, the number of loops that can be connected to the device. Also, control panels differ in the method of notification. They can activate alarm devices or monitor the progress of evacuation and control other systems.
Peripheral actuators.
In fire alarm hardware systems, peripheral devices are those connected to the control panel via a communication line and having their own design and functionality (except for fire detectors). These include:
- remote control panel - it provides local control of the fire alarm at a remote site;
- short circuit monitoring and isolation device – used in loops burglar alarm having a ring structure to ensure the operability of the system in the event of a short circuit in one of the peripheral devices;
- relay modules – expand functionality automatic control devices from the control panel;
- sound/light alarms – used to notify personnel about emergency situation on site.
TYPES OF FIRE ALARMS
On at the moment There are three main types of automatic fire alarms:
- threshold;
- targeted survey;
- addressable analog.
Threshold.
Typically used in small fire alarm systems to monitor objects with medium and low fire hazard, including for most residential properties. The main difference is the use of fire detectors with a response threshold set at the manufacturer.
The structure of a threshold fire alarm most often has a radial topology with loops arranged. That is, loops emanate from the control panel, to which fire detectors are connected. When at least one of them is triggered, an alarm signal for the entire loop is activated.
Considering that one loop can serve several rooms (up to 20-30 detectors), the information content of this type of fire alarm is quite low.
The main advantages of such a system are:
- affordable price of equipment;
- ease of installation and configuration.
Possible disadvantages of threshold alarm:
- fire detection in late stages;
- lack of monitoring of detector performance;
- low information content;
- a large amount of work on installing the cable structure.
Targeted survey.
The main difference between addressable interrogation fire alarms and threshold ones is the algorithm for connecting the control panel with fire detectors. In this case, the monitoring device does not wait for a signal to change the detector mode, but periodically polls its current state.
This principle of operation allows you to obtain data on the performance of the sensors, and also expands the list of information notifications from one to four: “Normal”, “Fire”, “Break”, “Fault”.
The architecture of constructing a fire alarm network is ring-shaped. This type of automatic fire alarm is widely used to control similar general purpose premises: offices, shops, medical and educational institutions.
Obvious advantages of such a fire alarm organization:
- monitoring the performance of sensors;
- high information content;
Addressable analogue system.
At the moment this is the most best option construction of fire alarm systems. The main difference from previous types is that the analysis of information and decision-making on switching to alarm mode is carried out not by a fire detector, but by a control panel (PKP).
The control panel itself is a much more complex device, as it performs a number of functions: continuous questioning of doctors, analysis of the information received, comparison of data with limit values entered into its memory, making a final decision based on consolidated data from several types of detectors.
Thus, not only is the percentage of false alarms significantly reduced, but it becomes possible to determine the location and time of a potential fire in the early stages as a result of a combination of several factors, each of which could not trigger the system.
AUTOMATIC FIRE ALARM - SYSTEM COMPOSITION
Once a fire source is detected by one or more detectors, the fire alarm system must perform a specific set of actions aimed at:
- launching a warning and evacuation system;
- the most accurate localization of the fire location;
- control of other engineering systems according to a specific algorithm.
Alert.
Informing staff and visitors in the premises about the occurrence of emergency related to the fire. The warning system, depending on its operating principle, can be light, light-sound or speech. The choice of a specific type of warning system depends on the characteristics of the structure: the number of storeys of the building, the area of the premises, the height of the ceilings.
This is laid down at the design stage of the building’s fire alarm system in accordance with the requirements of regulatory documentation. The warning system should include marking of the main escape routes, including illuminated “Exit” signs so that the doorway leading out of the building can be identified even in a smoky room.
Unlocking doors.
If the building has an access control system (ACS), the fire alarm system must generate a signal to turn off turnstiles, doors and other devices blocking passages.
If the building has an elevator service, then the fire alarm control panel sends a command to force all sheets to be sent to the first floor, open the doors and deactivate the device.
System activation automatic fire extinguishing and smoke removal.
Depending on the specific use of the building, the fire extinguishing system installed in it may be filled with gas, powder, water or water-foam. The choice of a specific fire extinguishing agent, as well as the placement of fire extinguishing modules, depends on the property located in the room and regulations fire safety.
The operation of the smoke removal system is to remove smoke, heat and other combustion products outside the building. During a fire, the air supply through the ventilation system must be shut off. In addition, the function of preventing the spread of smoke along the main evacuation routes must be implemented.
* * *
© 2014-2020 All rights reserved.
The materials on the site are for informational purposes only and cannot be used as guidelines or normative documents.
Fire alarm(FS) is a set of technical means whose purpose is to detect fire, smoke or fire and promptly notify a person about it. Its main task is to save lives, minimize damage and preserve property.
It may consist of the following elements:
- Fire alarm control device (FPKP)– the brain of the entire system, exercises control over loops and sensors, turns on and off automation (fire extinguishing, smoke removal), controls sirens and transmits signals to the remote control of a security company or a local dispatcher (for example, a security guard);
- Various types of sensors, which can react to factors such as smoke, open flame and heat;
- Fire alarm loop (SHS)– this is the communication line between sensors (detectors) and the control panel. It also supplies power to the sensors;
- Annunciator- a device designed to attract attention, there are light - strobe lamps, and sound - sirens.
According to the method of control over loops, fire alarms are divided into the following types:
PS threshold system
It is also often called traditional. The operating principle of this type is based on changing the resistance in the fire alarm system loop. Sensors can only be in two physical states "norm" And "fire" If a fire factor is detected, the sensor changes its internal resistance and the control panel issues an alarm signal on the loop in which this sensor is installed. It is not always possible to visually determine the location of the trigger, because in threshold systems, an average of 10-20 fire detectors are installed on one loop.
To determine the fault of the loop (and not the state of the sensors), an end-of-line resistor is used. It is always installed at the end of the loop. When using fire tactics “PS triggered by two detectors”, to receive a signal "attention" or "possibility of fire" An additional resistance is installed in each sensor. This allows you to use automatic systems fire extinguishing at the facility and eliminating possible false alarms and property damage. The automatic fire extinguishing system starts only in the event of simultaneous activation of two or more detectors.
PPKP “Granit-5”
The following PPCPs can be classified as threshold type:
- "Nota" series, produced by Argus-Spectrum
- VERS-PK, manufacturer VERS
- devices of the “Granit” series, manufactured by NPO “Sibirsky Arsenal”
- Signal-20P, Signal-20M, S2000-4, manufacturer of NPB Bolid and other fire-fighting devices.
The advantages of traditional systems include ease of installation and low cost of equipment. The most significant disadvantages are the inconvenience of servicing fire alarms and the high probability of false alarms (resistance can vary from many factors, sensors cannot transmit information about dust levels), the number of which can only be reduced by using a different type of substation and equipment.
Address-threshold PS system
A more advanced system is capable of automatically periodically checking the status of sensors. Unlike threshold signaling, the operating principle is based on a different algorithm for polling sensors. Each detector is assigned its own unique address, which allows the control panel to distinguish them and understand the specific cause and location of the malfunction.
The Code of Rules SP5.13130 allows the installation of only one addressable detector, provided that:
- The PS does not control fire alarm and fire extinguishing installations or type 5 fire warning systems, or other equipment that, as a result of startup, can lead to material losses and reduced human safety;
- the area of the room where the fire detector is installed is not larger than the area for which this type of sensor is designed (you can check it using the technical documentation for it);
- the performance of the sensor is monitored and in case of a malfunction a “fault” signal is generated;
- It is possible to replace a faulty detector, as well as detect it by external indication.
Sensors in addressable threshold signaling may already be in several physical states – "norm", "fire", "malfunction", "attention", "dusty" and others. In this case, the sensor independently switches to another state, which allows you to determine the location of a malfunction or fire with the accuracy of the detector.
PPKP “Dozor-1M”
The address-threshold type of fire alarm includes the following control panels:
- Signal-10, manufacturer of airbag Bolid;
- Signal-99, produced by PromServis-99;
- Dozor-1M, manufactured by Nita, and other firefighting devices.
Addressable analog system PS
The most advanced type of fire alarm to date. It has the same functionality as addressable threshold systems, but differs in the way it processes signals from sensors. The decision to switch to "fire" or any other condition, it is the control panel that accepts it, and not the detector. This allows you to customize the operation of the fire alarm according to external factors. The control panel simultaneously monitors the status of the parameters installed devices and analyzes the obtained values, which can significantly reduce the likelihood of false alarms.
In addition, such systems have an undeniable advantage - the ability to use any address line topology - tire, ring And star. For example, if the ring line breaks, it will split into two independent wire loops, which will fully retain their functionality. In star-type lines, you can use special short-circuit insulators, which will determine the location of the line break or short circuit.
Such systems are very convenient to maintain, because Detectors that require purging or replacement can be identified in real time.
The addressable analogue type of fire alarm includes the following control panels:
- Two-wire communication line controller S2000-KDL, manufactured by NPB Bolid;
- Series of addressable devices “Rubezh”, manufactured by Rubezh;
- RROP 2 and RROP-I (depending on the sensors used), manufactured by Argus-Spectrum;
- and many other devices and manufacturers.
Scheme of an addressable analogue fire alarm system based on PPKP S2000-KDL
When choosing a system, designers take into account all requirements terms of reference customer and pay attention to the reliability of operation, cost installation work and routine maintenance requirements. When the reliability criterion for a simpler system begins to decrease, designers move to using a higher level.
Radio channel options are used in cases where laying cables becomes economically unprofitable. But this option requires more money for maintenance and maintaining devices in working condition due to periodic replacement of batteries.
Classification of fire alarm systems according to GOST R 53325–2012
Types and types of fire alarm systems, as well as their classification are presented in GOST R 53325–2012 “Fire fighting equipment. Technical means fire automatics. General technical requirements and test methods."
We have already discussed addressable and non-addressable systems above. Here we can add that the former allow the installation of non-addressed fire detectors through special extenders. Up to eight sensors can be connected to one address.
Based on the type of information transmitted from the control panel to the sensors, they are divided into:
- analog;
- threshold;
- combined.
According to the total information capacity, i.e. total number connected devices and loops are divided into devices:
- low information capacity (up to 5 shs);
- average information capacity (from 5 to 20 shs);
- large information capacity (more than 20 shs).
According to information content, otherwise according to the possible number of notifications issued (fire, malfunction, dust, etc.) they are divided into devices:
- low information content (up to 3 notices);
- medium information content (from 3 to 5 notices);
- high information content (from 3 to 5 notices);
In addition to these parameters, systems are classified according to:
- Physical implementation of communication lines: radio channel, wire, combined and fiber optic;
- In terms of composition and functionality: without the use of computer technology, with the use of computer technology and the possibility of its use;
- Control object. Management of various fire extinguishing installations, smoke removal means, warning and combined means;
- Expansion possibilities. Non-expandable or expandable, allowing installation in a housing or separate connection of additional components.
Types of fire warning systems
The main task of the warning and evacuation control system (WEC) is to timely notify people about a fire in order to ensure safety and prompt evacuation from smoke-filled rooms and buildings to a safe area. According to Federal Law-123 “ Technical regulations on fire safety requirements" and SP 3.13130.2009, it is divided into five types.
The first and second types of SOUE
Most small and medium-sized facilities, according to fire safety standards, must install the first and second types of warning.
At the same time, the first type is characterized by the mandatory presence of an audible siren. For the second type, “exit” light signs are added. A fire alarm must be triggered simultaneously in all premises with permanent or temporary occupancy.
The third, fourth and fifth types of SOUE
These types refer to automated systems, the triggering of an alert is completely assigned to automation, and the role of a person in managing the system is minimized.
For the third, fourth and fifth types of SOUE, the main method of notification is speech. Pre-developed and recorded texts are transmitted that allow evacuation to be carried out as efficiently as possible.
In the 3rd type additionally, illuminated “exit” signs are used and the order of notification is regulated - first to service personnel, and then to everyone else according to a specially designed order.
In the 4th type there is a requirement for communication with the control room inside the warning zone, as well as additional light indicators for the direction of movement. Fifth type, includes everything that is listed in the first four, plus the requirement for separate inclusion of light signs for each evacuation zone is added, full automation of control of the warning system is provided and the organization of multiple evacuation routes from each warning zone is provided.
Since ancient times people have used various ways transmitting information about the occurrence of events over a considerable distance. They rang bells or lit fires. Modern life connected to different devices, the operation of which is controlled remotely using different alarms. Fire alarm systems in residential buildings and plays an important role at industrial facilities.
The purpose of the fire alarm system is to promptly transmit data about a fire to the duty service fire department, which must quickly take measures to extinguish the fire. In addition, a fire alarm can remotely activate fire extinguishers that are configured in advance to extinguish a fire at a specific facility, notify people of the need to evacuate, and also transmit information about a fire to additional control centers.
Classification of fire alarms
There are three types of fire alarm systems that are worth considering in more detail.
Threshold alarm
Most often, threshold alarms are used in small systems to monitor objects with low and medium fire danger, as well as for residential buildings. Their main feature is the use of detectors with a factory threshold. The block diagram of such a signaling is made in the form of a radial arrangement of loops. Loops diverge from the control panels and are connected to various sensors. If one sensor is triggered, the alarm signal will come from the entire loop.
Considering that one loop can be connected to several different rooms, then when one sensor is triggered, it will not be clear where exactly the fire occurred, that is, the information content of the threshold alarm is very low.
In addition, the disadvantages of the threshold system include:
- The installation of system cables is very labor-intensive.
- Lack of detector serviceability testing.
- Late detection of fire.
Advantages:
- Easy setup and installation.
- Low cost.
Addressable polling alarm
The main feature of addressable interrogation signaling is the type of communication between control and control devices and detectors. In this type of communication, the control device does not wait for a signal to change the operating mode from the sensor, but periodically queries it about its status. This makes it possible to obtain information about the health of the sensors and expands the list of possible notifications.
The structure of this type of network is made in a ring. The ring system has become popular for similar types of premises: offices, educational institutions, shops.
Advantages
- Great information content.
- Possibility of monitoring the health of sensors.
Addressable analog signaling
Currently, this type of fire alarm system is the most common and optimal. Its main difference from other types is that the processing of information and the decision to issue an alarm signal is performed not by the detector, but by the receiving and control device, which is a more complex device.
It performs several functions: constant polling of detectors, processing information, comparing data with threshold values, making decisions based on data different types detectors. Therefore, the number of false alarms is reduced, and it becomes possible to identify the exact location and time of the fire without a time delay due to several factors. Separately, each factor would not trigger the system.
Fire alarm device
Any fire alarm system, regardless of its type and size, consists of the following devices:
- Detectors (sensors) are sensitive detectors that can detect a fire by analyzing environmental factors: high temperature, smoke, etc.
- Reception and control devices receive and process information received from sensors.
- Executive peripheral devices - control panels, insulation monitoring, relays, sirens.
Fire alarm systems may also include central control devices. For small objects they are designed as a control panel, with which you can set some commands.
Larger alarms can operate under the control of a computer with a special program. Most often this is organized in fire systems, where statistical data is stored and processed on a computer.
Detectors
Such devices are sensors that monitor the state of the protected object, monitoring some parameters inherent in the occurrence of a fire: smoke, temperature, infrared radiation.
Detector sensors are characterized by certain parameters:
- Operating principle.
- The method of transmitting data to the receiving control devices.
- Type of parameter control.
The main parameter is the principle of creating an alarm signal. Passive detectors, which are the most popular, respond to temperature or smoke when they are directly applied to the sensor. The active type of detectors monitors infrared radiation and includes a receiver and emitter.
Reception and control devices
The control device that receives information is the main control element of the fire alarm system. It checks the status of the loops, receives information from detectors and transmits data to the central control panel. When operating in autonomous mode, the control panel controls warning of people, automatic fire extinguishing and smoke removal.
Classification of devices by:
- Purpose: managers, security and fire fighters, firefighters.
- Informative: low-informative - two types of messages, medium-informative - up to 5 messages, multi-informative - more than 5 messages.
- Type of communication: wired, via radio channel.
- Type of train: radial, loop.
- Climatic version: for warm and cold rooms.
- Method for turning on the standby mode: separately for each loop, group, combined.
- Location of the spare power supply: built-in, external.
- Number of loops (information capacity): low information content - up to 5 loops, medium information content - up to 20 loops, high information content - up to 100 loops.
- Specialized control devices for explosive areas.
Actuators
In fire alarm systems, executive peripheral devices are those that are connected to the control and control devices via a communication line and are housed in a separate housing:
- Remote controller remote control, which is used to perform remote control alarm.
- The insulation monitoring device is used in fire alarm loops with a ring structure to ensure the functioning of the system in the event of a short circuit.
- Relay modules increase the ability of devices to operate in automatic mode.
- Light and sound alarms are used to notify people of a fire.
Operating principle of the fire alarm system
After detectors detect a fire, the system should operate as follows:
- Enable notification of people and the system about their evacuation.
- Determine the location of the fire most accurately.
- Manage other systems.
Alert
All visitors and staff of the establishment where the fire occurred must be informed about this. The warning system can be voice, light-sound or light. Its choice depends on the building parameters: ceiling height, area, number of floors.
These parameters are taken into account when developing fire alarms in accordance with regulatory documents. The notification should include marking the exit routes with illuminated signs so that it is visible even in the smoke.
Unblocking outputs
If the building has an access control system (turnstiles, interlocking doors, etc.), then the alarm system should signal to turn it off. If the building has elevators, the alarm sends a command to send the elevators to the 1st floor, open their doors and turn off the elevators.
Starting smoke removal and fire extinguishing
Fire extinguishing systems in a building can be different: foam, water, powder, etc., depending on the specifics and type of building. The fire extinguishing agent is selected depending on the type of property located in the building, as well as in accordance with fire safety regulations.
A smoke extraction system removes smoke and heat to the outside of the building. In the event of a fire, ventilation must be closed to prevent air from entering the fire site. A system must also be in place to prevent smoke from entering the exit path.
How the smoke sensor works
The sensor is placed on the ceiling, where smoke can concentrate during a fire. It consists of a housing, an electronic device and an optical system. These elements are collected into a single module. The sensor operates by detecting smoke using an optical system. It includes an LED that directs the light beam, a photocell that receives this beam and converts it into an electric current signal.
The beam from the LED does not hit the photocell, as it is directed in one direction. When smoke occurs, light rays are reflected in different directions and hit a photocell, which is triggered. Electronics sends commands to alarm control and control devices via communication channels.
Action of thermal sensors
These sensors are also fixed to the ceiling. They work in the following cases:
- Achieving a certain rate of temperature increase.
- Exceeding the permissible temperature threshold.
Operating principle of the fire sensor
Flame detectors are widely used sensors. They react to open flames or smoldering fires without producing smoke.
A highly sensitive photocell detects the appearance of a spectrum of optical flame waves. The fire sensor design is complex, so the sensor is expensive. In this regard, they are rarely used in residential buildings, but they have become popular in gas and oil production enterprises.
Simple flame sensors can be triggered by welding work, bright sunlight, some types of lamps. To prevent false alarms, special light filters are used.
Fire truck sirens are not uncommon in big cities. This suggests that statistics about large quantities fires are a reality. Not only shopping and entertainment centers are burning, apartments and houses, offices and factories are burning. A common reason- people's negligence. Someone didn’t put out an abandoned cigarette, someone didn’t check the quality of the electrical wiring in time, someone forgot the kettle on the stove, the list is endless. Preventing fire is the main task assigned to fire safety services. And today it can be solved simply - a fire alarm.
In order to promptly detect the first signs of fire, special devices are needed, also known as sensors, that respond to smoke in the room and other parameters environment. Experts call them primary recording devices. They react to the appearance of smoke, rising temperature and begin to emit signals. These are the most simple models. There are advanced devices that activate automatic warning systems, transmit a call signal to the fire department of the Ministry of Emergency Situations, and additionally independently turn on the automatic one.
Like all devices, detectors get dirty over time and become covered with a layer of dust, which makes their functions rapid response and responses are reduced. That's why It is important to check devices for their quality condition, which must comply with regulations.
How does the alarm work?
Purely schematically, a fire alarm is a complex that, in addition to detectors, includes:
- security and fire panel, which ensures the start of the fire and security system;
- reception and control room, which collects, processes and transmits signals;
- peripheral devices that provide communications, power supply, form and activate the fire extinguishing system itself;
- a complex that processes all signals coming from various objects and transmits them to the Ministry of Emergency Situations.
Since there are several types of fire alarm systems, they operate on different principles. For example, threshold sensors poll each sensor separately at certain intervals. This way it becomes clear which one worked. The simplest threshold models work on the principle of breaking the loop on which the sensor is located. It is the break that is the signal indicating that a fire has started in the location area.
For addressable analog devices, the operating principle is based on environmental parameters. In this case, air. Does it contain a concentration of smoke sufficient to indicate a fire or not?
Varieties
Speaking about the types of fire alarm systems, it must be noted that everything depends on the configuration and operating principle. And since there is a huge variety of components on the market, accordingly, by selecting them for each system, you can assemble a model that is different from others, both in terms of the types of components and the principle of operation. Therefore, types of fire alarms are presented in five categories:
- threshold with a radial type structure;
- threshold ones with a model-type structure;
- targeted survey;
- addressable analogue;
- integrated.
Threshold
Here, sensors are used that are adjusted to a certain response threshold (sensitivity). Hence, in principle, the name. For example, if the detector is set to a certain ambient temperature, then it will only work when the room temperature rises to the specified limit. The rest of the time he will simply be “silent.”
Most often, threshold circuits are arranged according to the ray principle. This is when cables (wires) are stretched from the control panel to the sensors. The more loops, the more tightly the room can be covered for response. Each beam has up to 30 detectors. If one of them works, the loop number will be displayed on the panel. This means that a fire has started in this area, and a signal is given.
Threshold fire alarm systems are usually installed inside small-sized objects: shops, schools, kindergartens, cinemas, etc. Speaking about the advantages, it is necessary to note the low price of the network and ease of installation. As for the disadvantages, here, first of all, it is necessary to indicate the minimum information content, that is, the system can show the approximate zone of occurrence of the fire, and not the exact location. And if the distribution beam is long enough, covering several rooms, then all rooms will be affected.
Addressed survey
In such schemes, each sensor-detector is assigned the address of its location inside the object. The loops are arranged not in rays (radially), but in circles. And up to 200 sensors can be connected to each ring section. The latter can be temperature, smoke, humidity and others.
Different address system from the threshold one in that in the latter the control panel “wait” for one of the sensors to trigger. In the first, the panel itself polls the detectors in what state they are at a certain periodicity. Hence the advantages of this type:
- early detection of fire;
- the ability to change the sensitivity threshold of devices at your discretion;
- simplicity and low price installation work and preventive measures.
Addressable analog
Analogue differs from interrogation in that between the detectors and the control panel there are special devices, which are called reception and control rooms (PKP). They are the ones who poll the sensors, and not the latter transmit signals. This complicates the system, but makes it more flexible, with the ability to quickly respond to a fire.
The control panel not only interrogates the sensors, but also analyzes the received signals and compares the received data with sensitivity thresholds. And on all this he makes a decision. This is why the number of false positives is reduced. At the same time, the PKP analyzes all factors without reducing the response time.
In all respects, addressable analogue fire alarm systems are superior to all others. But they have one serious drawback - the high price.
Integrated
What does integrated fire alarm mean? It's about connecting with others. engineering networks security. This makes it possible to quickly react to the appearance of a fire and calmly begin evacuating people without panic. That is, such a model not only notifies in time about the start of a fire, but automatically opens entrance doors, turnstiles, turns off ventilation.
How the integrated circuit works:
- as soon as the signal arrives at the control panel, the ventilation is turned off and smoke removal is turned on instead;
- the facility is completely disconnected from power supply, except for fire extinguishing and alarm systems;
- lighting (emergency) and light indication are turned on;
- an alert is turned on;
- emergency exits open.
These are small-sized devices that monitor ambient air parameters. Today manufacturers offer a fairly wide model range, which differ from each other not only appearance And overall dimensions, but also the principle of operation, the type of controlled environmental parameter and methods of transmitting information data to the prefabricated control panel.
According to the principle of operation, fire detectors are divided into passive and active. The first ones work only to trigger, the second ones not only trigger, but also control environmental parameters. The latter, as the threat increases (fire spread, temperature increases), transmit different signals to the remote control in terms of power level and intensity.
The second type of division of sensors is the control of different parameters. There are five positions here:
- smoke,
- temperature or thermal
- flame control,
- water leaks,
- gas leaks (carbon carbon or natural gas).
Smoke ones are most often used, because smoke is the very first sign of a fire, which spreads most quickly throughout the internal spaces of the object.
How does a smoke detector work?
Controls smoke in rooms. That is, if a certain concentration of a smoke screen suddenly appears inside the object in any part of it, the device will immediately work, sending a signal to the remote control.
The sensor is based on an optical operating principle. It consists of a photocell, a chamber with air is installed in front of it, and behind it an LED is mounted, which sends a beam of light to the photocell through a chamber with air. If the amount of smoke inside the room increases, the light beam begins to dissipate. That is, less light energy reaches the photocell. This is the reason for the trigger.
Rules for installing smoke and heat detectors
In paragraph No. 13 from SP 5.13.130.2009 there is a table numbered 13.3, which shows the installation dimensions of smoke sensors.
| Ceiling height, m | Controlled area, m² | Distances between: | |
| sensors | sensors and walls | ||
| up to 3.5 | up to 85 | 9 | 4,5 |
| 3,5-6 | 70 | 8,5 | 4 |
| 6-10 | 65 | 8 | 4 |
| 10-12 | 55 | 7,5 | 3,5 |
Table 13.5 clearly shows the distances between thermal sensors and between them and walls. Here is the table.
The consumer market offers the buyer various systems alarms that can be equipped country house, cottage, apartment or provide protection garden territory. Equipment for burglar and fire alarms, depending on the type, can be purchased separately, but there are also devices combining two types of systems - security and fire.
Technical means are designed to provide owners with information indicating the condition of controlled objects, save data, and also convert the received alarm message into sound and light signals.
A characteristic feature of security and fire alarm devices is their classification, which provides for the division of detectors according to the following parameters:
- according to their intended purpose (place of application);
- according to the operating principle of the device;
- by the number of detection zones;
- by type of controlled and protected areas;
- by the maximum range of the detection system;
- on structural manufacturing;
- according to the method of electrical power supply to devices.
In addition to classifying detectors by parameters, security and fire alarm divided into three types, which differ from each other in the location of the sensors.
- One-border. Carries out control along the perimeter of the house or along the perimeter of individual premises. Controls doors, windows, technical entrances.
- Double border. Performs all the functions of the one-line system, and also monitors the approaches to the building and the condition of the territory adjacent to the site.
- Multi-border. Functionally it combines the two previous security systems, but additionally monitors individual valuable items inside the house, garage or workshop.
The operation of a multi-border notification system can be ensured from one or several interconnected or independent autonomous points. The alarm system of various protected objects, objects and territories can be switched on and off independently of each other.
Regarding the place of application
The choice of equipment largely depends on the location of its application. According to their purpose, OPS can be characterized by several types:
- apartment alarm;
- alarm system for the cottage;
- alarm for country house;
- alarm for personal plot and areas adjacent to the house.
An owner who wants to install an alarm system for security purposes at home or the surrounding area should be well aware that as design developments become more complex, costs increase for the operation of security systems, and the cost of devices also increases.
For apartment
To protect apartments in multi-storey residential buildings, they are mainly used single border notification systems, which control the premises along the entire perimeter, including the entrance doors and windows of the apartment.
The equipment supplied by the manufacturers includes:
- system unit;
- remote control;
- motion sensor;
- bracket for mounting the sensor;
- sensors that respond to the opening of windows and doors;
- sensor batteries;
- power adapter;
- sound detector;
- GSM antenna;
- instructions.
Security alarms for apartments can be additionally equipped with various types of sensors that respond to broken glass, the presence of smoke or gas in the room, as well as sensors that respond to vibration or flooding.
For a cottage
Private cottage security is provided two-border or multi-border systems alerts. For external security of an object, you will need from 6 to 12 sensors and a four-zone monitoring and signal receiving device.
To protect cottages, door magnetic contact sensors, single-frequency and dual-frequency sensors that respond to broken glass, as well as various types motion sensors. To create additional lines of protection, internal security alarm sensors are used.
To eliminate the possibility of false alarms and timely detect real danger, when choosing equipment for cottage security special attention it is necessary to pay attention to external sensors that do not respond to weather conditions.
In cottages protected by devices, IR motion sensors are mainly used, which are equipped with a double PIR element and equipped with a built-in filter. This system eliminates any reaction to the presence of pets in the house.
For a country house
Due to the remoteness of the security facility from the city, difficulties may arise with the maintenance of complex engineering systems. Some owners who want to install an alarm system prefer simpler but reliable protection options, completing them required quantity external motion sensors.
Devices placed on the walls along the perimeter of the building make it possible to create protected area up to 5 meters wide, which provides early detection of an intrusion attempt and helps to take necessary measures protection.
Equipment with light external alarms, as well as sound external signals, has a deterrent effect on intruders and requires virtually no maintenance. A cable running along the walls of a building is usually hidden from prying eyes by embedding it into the wall using a construction method.
When protecting a country house, the use of internal sensors is possible at the request of the owner, as an additional protective line.
For the site
When choosing technical equipment, which will ensure the protection of the territory, must be taken into account characteristic features terrain, relief, and possible restrictions visibility.
To protect the site it is mainly used:
- Vibration protection system. Reacts to ground vibration from a person walking on it. This method of protection allows you to control an area up to 200 meters long. Response of devices to the movement of animals, passage road transport, precipitation and wind gusts at speeds up to 20 m/sec are excluded.
- Capacitive system. It is used mainly in conditions of complex perimeters or terrain. Reacts to an intruder touching the top edge of the fence.
- Radio wave system. Reacts and issues an alarm signal when a person crosses the terrain. The system is resistant to atmospheric influences, the creation of electromagnetic interference, and is not distracted by movement vehicles and animals crossing the site.
- Radio beam system. There are two types:
- single-position, emits radio waves into space, giving an alarm signal to inform about the appearance of an intruder;
- two-position, helps create an electromagnetic barrier above the soil surface. It is impossible to cross such a protected area unnoticed.
Almost all security devices are equipped with an automatic alarm mode, which, in a prescribed sequence, informs users by auto-dialing to their phone numbers.
What types of security and fire alarms are there?
Fire alarm system combines two types of systems: security and fire. Automatic fire alarms are divided into three types:
Non-addressable alarm system
Non-addressed OPS. A simple threshold system that uses detectors with two positions - “normal” and “fire”. The system is triggered when a certain parameter is exceeded above a specified threshold. This could be excess temperature or smoke levels. The loop number is recorded on the control panel security detectors, the room address and sensor number are not transmitted to the panel. It is used to protect objects and territories with a small area.
Addressable alarm system
. Used to protect objects with medium and large sizes. The system has the ability to determine points of entry into the protected area, as well as fire points, thanks to the address schemes and information exchange protocols built into the detectors. This type of fire alarm is usually installed in schools, kindergartens and other important social institutions.
Addressable analog signaling
Addressable analog OPS. This type of fire alarm systems is characterized by high efficiency, quality and reliability. The controller constantly analyzes information that continuously comes from installed sensors to the main panel. Monitors fires, sudden increases in temperature, the appearance of smoke, intrusion into the territory, etc.
Based on intrusion and fire detection technology
The alarm system is completely dependent on monitoring sensors that promptly respond to the detection of fires and intrusions into the protected area. Sensors are divided into several types, which allows you to use a variety of solutions when installing an alarm system.
Fire and security alarm systems are divided according to the types of sensors:
- ultrasonic;
- acoustic;
- vibration;
- infrared;
- magnetic contact;
- light;
- radio wave;
- combined and other systems.
The OPS can be equipped with other sensors, the types of which are difficult to list. Among the monitoring devices used in the system there are gas analyzing and smoke detectors, water leakage control sensors, multi-sensor devices that analyze a fire based on four signs, etc.
Characteristic features of wired and wireless fire alarm systems
Wired alarm involves installing a cable on the walls of a building and, as a rule, provides in advance, even before finishing begins. This method of security is considered more reliable than its wireless counterpart due to the absence of incoming radio signals that can be interrupted.
In a wired security system, you can achieve the maximum possible range of protected areas, control not only the house and territory, but also the gates, as well as the fencing of the site along the entire perimeter.
The wireless system is easy to install. Structural elements devices communicate using radio waves (signals), which are tuned to the required frequency. The wireless alarm system is mainly equipped autonomous sensors, allowing you to control the windows and doors of the house, approaches to the building on distance not exceeding 100 meters, as well as fire safety on the territory.
Upon purchase security equipment not only the features of the object are taken into account, intuition and personal experience person. In order to select the equipment correctly, it is necessary to make an accurate calculation of all the characteristics of the purchased devices, and this work can only be done by professionals.
