Classification of security and fire systems by types and types can be made according to a number of various parameters. The most obvious one is purpose. There are three large groups here:
TYPES OF SECURITY ALARMS
Included security systems can also be used Various types sensors, which are wired and wireless, differ in the way they detect intrusion and process the signal. The principles of constructing security systems may vary depending on their purpose: for a house and cottage, apartment, various objects organizational and legal forms
An elementary option is an alarm system consisting of one motion sensor with a built-in GSM module. Despite its apparent simplicity, this type of security is quite reliable and is well suited for protecting small country houses.
In general, the security alarm system uses several types of detectors, which are classified according to their purpose and principle of operation. To ensure reliable security, sensors are used to monitor:
- opening windows and doors;
- breaking of glazed surfaces;
- breach of walls, partitions and ceilings.
The listed equipment is used to protect the perimeter of the premises. In addition, there is a group of sensors that detect movement inside or on the approaches to the object. The selection of specific types of detectors is made taking into account individual characteristics object to be protected.
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. Prevent fire - here the main task posed to fire safety services. And today it can be solved simply - a fire alarm.
In order to promptly detect the first signs of fire, it is necessary special devices, they are also sensors that react 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, making 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 the varieties of systems fire alarm several, then they work according to different principles. For example, threshold sensors poll each sensor individually 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 types of systems fire alarm, 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, 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.
The addressable system differs from the threshold system 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 special devices are installed, which are called control panels (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 the lineup, 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 smokers are most often used, because smoke is the very first sign of a fire, which spreads most quickly throughout internal spaces 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 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 according to 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 factors external environment(smoke, temperature, etc.);
- control panel– a device that collects and processes information received from detectors;
- sound and light alarms (sirens, displays, lamps).
Besides, in automatic systems Centralized monitoring and control devices can be used. 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 specially installed software. 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 of 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 security alarm loops having a ring structure to ensure the operability of the system in the event 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 of an emergency situation at the facility.
TYPES OF FIRE ALARMS
On this 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 operating principle 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 automatic fire alarm is widely used to control similar premises general purpose: 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, since it carries out whole line 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 an emergency situation involving a 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 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 fire safety standards.
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.
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The installation of fire alarms in schools is mandatory in accordance with the requirements of 123-FZ. Absence, improper condition or non-compliance with standards is not only an administrative, but also a criminal offense. Taking into account the specifics of operation, special requirements are imposed on fire alarms used in schools:
- high sensitivity of the equipment and comprehensive testing of all factors for identifying the source of fire;
- the control panel must be located in a room with limited access;
- cables connecting the control panel and detectors must be in heat-resistant insulation that does not emit carcinogenic or toxic substances during operation or thermal exposure.
Specifics of the fire alarm system at school
Premises should be equipped with hybrid sensors that monitor several parameters at once, or with several sensors that monitor air composition (the appearance of smoke or carbon dioxide), temperature (threshold value and dynamics of change), and the presence of infrared radiation (radiant energy from an open flame). Detectors must be installed both in the main premises and in technical, utility and basement areas.
Gasket cable networks must be implemented in a closed way using grooves or boxes located out of direct reach. This will not only prevent students from damaging cables, but will also allow the system to monitor the situation during a fire, transmitting relevant information.
It is allowed to use only addressable or addressable-analog systems, which can not only detect the very fact of a fire, but also determine its location. At the same time, the use of addressable analogue systems is preferable, since they are more reliable and fully comply with the fire safety requirements for the protection class for schools and preschool educational institutions.
UNITEST development and production systems
- "MINITRONIK A32" for schools from 50 to 5 thousand square meters. m.
- "MINITRONIK A32M" for schools from 50 to 10 thousand square meters. m.
School fire alarm maintenance
The regulations for maintaining fire alarm systems in schools include the following work:
- external examination to identify possible damage housings;
- checking the functioning of detectors, control panel and software in complex;
- if necessary, adjust settings and sensitivity of detectors;
- Cleaning equipment first smoke detectors(once every 3 months);
- checking the power supply, measuring battery parameters, replacing them if necessary.
An automatic fire alarm (AFS) is installed in the premises for safety and timely notification of a fire. The complex not only notifies, but also turns on fire extinguishing installations. The alarm system is installed without fail - the requirement is provided for by law and acts of the Ministry of Emergency Situations. Buildings and structures are inspected by a fire safety officer and after that an APS is installed.
The requirements standards for an automatic fire alarm system are minimal: timely detection and notification of fire. Automatic fire alarms allow you to quickly evacuate people and avoid large losses material assets.
Fire extinguishing is carried out by other installations (fire extinguishing installation). It is also possible to use APS in combination with video surveillance (OPS - fire and security alarm).
Fire alarm consists of complex technical elements:
- touch sensors;
- cable routes;
- control panel.
Types of systems
An automatic fire alarm uses sensors to transmit information to the control panel, which indicates where the fire has occurred. The types of alarms are varied and depend on the requirements (for example, on the area of the object).
Types of APS:
- address;
- non-addressed;
- addressable analog.
Requirements for not address system minimal (the area of the structure is small). They install alarms at small objects, since the touch sensors are combined into a common loop. If one of the sensors is triggered, the alarm system informs about the fire with a general signal. It is impossible to determine which sensor was triggered - the loop number is indicated.
The requirements for the address system are broader. Install alarm systems in buildings with larger area, more than 1000 m. Touch sensors transmit information about the fire to the control panel and indicate the number. That is, you can determine which sensor was triggered (and not the loop). If one of the sensors is triggered, the alarm system informs about the fire with general and individual signals.
The requirements for analogue addressable systems are also extensive (the construction area is more than 1000 m). Install alarm systems in buildings with a large area and without cable routes. The principle of information transfer between the sensor and the control panel is telemetric. The control panel, based on data received from sensors, notifies about the occurrence of a fire.
There are also several types of sensors:
- smoke - react to the presence of smoke in the air;
- thermal – notify about temperature changes;
- light - react to light fluctuations;
- combined - turn on the system in the presence of smoke and temperature changes;
- multi-sensory and manual.
Preparing for installation
System installation begins with design drawings. The project examines the basic requirements for fire safety standards, GOSTs, and also takes into account the installation and operating principles of electrical equipment.
The plan drawings are done by a qualified engineer. The specialist inspects and marks the structure, taking into account the characteristics of the building. The engineer first identifies areas where the risk of fire is greatest. After this, drawings are drawn up.
So, the basic requirements for starting the installation:
- creating a project for installing an automatic fire alarm system (the plan not only helps with installation, but is also provided to the Ministry of Emergency Situations);
- calculate the duration of APS operation in offline mode;
- lay cable routes;
- it is necessary to take into account the properties and specifications of APS materials;
- identification of the most dangerous areas for fire;
- it is necessary to take into account the installation of equipment for supplying electricity to the APS system.
Installation
Various organizations are involved in installation of the system. Their work includes drawing up a project, purchasing and installing materials, obtaining a license from the authorities Fire safety, and Maintenance automatic fire alarm. The time to carry out the work is no more than a month (depending on the area of the structure).
Carrying out work:
- Laying cables according to system requirements.
- Installation of low-current networks.
- Installation, connection of touch sensors.
- Installation of the control panel (at the customer’s request in the specified room).
- Connection uninterruptible power supply electricity.
- Turning on and testing the APS.
System Maintenance
APS requires monthly maintenance. Typically, such services are provided by the same structure that installed the alarm system. The pricing policy for the service depends on the type of automatic fire alarm.
Maintenance service requirements:
- Checking the correct operation of individual elements and the entire complex.
- Adjusting APS settings.
- Repairing damage.
- Repair and maintenance of power transmission connections.
- Carrying out preventive work.
Automatic fire alarm – a complex system alerts. The complex is installed at the request of the Fire Safety Authorities. Installation and maintenance are carried out by various organizations. The cost of services varies depending on the type of alarm. The system not only guarantees the safety of material assets, but also of human lives.
