Types of fire alarm systems (security and fire alarms). Types of fire alarm systems (security and fire alarms) Types of fire systems

Public, commercial and industrial buildings with a large area and complex layout can be equipped with several types of fire safety systems. As a rule, their joint use is planned at the design stage.

If a fire occurs, the fire automatics switches over some functions of the access control system, turning off the locking devices and unlocking all doors located on the escape route. The elevators located in the building descend to the first floor and are blocked there with the doors open.

A comprehensive fire safety system for a building may consist of the following subsystems:

• Fire alarm;
• Alerts and ;
• Automatic fire extinguishing;
• Smoke removal and air pressurization (also functions as a ventilation shutdown).

The following types of fire alarms are currently used:

Threshold - the simplest and does not require additional settings. Each detector has a threshold value set at the factory by the manufacturer. The topology of constructing such a system is radial-beam. Up to 30 detectors can be attached to each beam. The installation can determine the presence of a fire in a controlled area, but not its exact location.

The only advantages of this system are the acceptable cost of equipment and further operation;

Flaws:

• Long response time;
• There is no centralized control over the functioning of sensors;
• Installation materials are wasted uneconomically on laying cable networks.

Targeted survey. The control panel of such a system sends a signal to the detectors at certain intervals in order to determine their current status. The following signals are used:

• Norm;
• fire;
• lack of connection to the sensor;
• detector malfunction.

Advantages of an addressable fire alarm system:

• Optimal combination of price and quality;
• Sufficiently high information content of the received signals;
• Ability to control the functioning of fire detectors;

The main disadvantage is that the fire occurs at a fairly late stage of development.

Addressable analogue is currently the most advanced fire alarm system. The main difference from previous systems is that the decision to sound an alarm is made by the central control panel, based on an analysis of the aggregate information from several types of detectors. This eliminates the possibility of false positives. Advantages of an addressable analogue fire alarm system:

• A ring (loop) structure is used, which significantly saves the amount of cable during installation;
• Scalability - you can expand several control sectors without significant financial investments;
• It is allowed to use a simple two-core wire;
• Availability of service functions:
• Issuing warnings about the need for sensor maintenance (cleaning, replacement);
• Maintaining an electronic log of events;
• Possibility of manual or automatic shutdown of some zones;
• Use of more advanced algorithms that prevent most false positives;
• Compatible with most utility systems;

Disadvantages are the rather high cost of the equipment and the complexity of its installation and further operation.

Warning and evacuation system

This installation works in tight integration with the fire alarm system. As a rule, it is aimed at a complex effect - light and sound. carried out using a siren, which transmits a modulated sound signal or text messages. Flashing beacons located along the entire route are used as light signals.

The main design differences in automatic fire extinguishing systems depend on the type of extinguishing agent that is used. There are the following types of automatic fire extinguishing systems.

Vodyanoye

As a rule, it consists of a pipeline system with shut-off valves, a pumping station connected to a centralized fire or domestic water supply network and a reserve water tank. There are deluge installations in which the pipeline is unfilled. Activation of such installations is carried out manually or by command from a fire detector. The main advantage is the ability to use in rooms with negative temperatures. Automatic fire extinguishing sprinkler systems are distinguished by the fact that water arrives directly in the pipeline under pressure. Water spray sprinklers have heat-sensitive locks that are destroyed by ambient temperature. Extinguishing the source of fire is carried out directly in the combustion zone, in contrast to deluge installations that flood the entire controlled area with water.

One of the varieties is dry-filled sprinkler systems for automatic fire extinguishing, in the pipelines of which there is air pressure, which is activated after the destruction of the thermal lock.

Water fire extinguishing installations with finely dispersed water. Modern highly efficient fire extinguishing systems are more similar in principle to deluge installations. After activation, water is sprayed through special nozzles throughout the room where they are installed. To increase the effectiveness of fire extinguishing, special chemical reagents are often added to the water.

Foam

Deluge systems can serve as automatic foam fire extinguishing installations. If the difference is that a foaming agent is added to the water tank. There are several gradations of foam expansion, depending on its density, which can be used to eliminate fires of liquid flammable substances or electrical installations.

The operating principle is as follows. Foam, being lighter than water and most liquid flammable substances, spreads over their surface, preventing the access of oxygen to the combustion zone.

Gas

Gas fire extinguishing systems are separate modules connected by an electric cable. Activation is carried out from the control panel after the evacuation of personnel. Yes, effective use requires that the room have a certain level of tightness. It is used primarily to extinguish fires in server rooms, data centers, libraries and archives, storerooms, museums or art galleries. The main advantage is the impossibility of causing material damage by fire extinguishing means and the ability to extinguish fire in operating electrical installations. powders have different characteristics of a fire extinguishing agent, which can be used to extinguish fires in premises of any type. The widespread distribution of powder automatic fire extinguishing systems is hampered by the following factors:

1. Low penetrating ability of the powder;
2. Difficulty breathing and reduced visibility in the fire extinguishing zone;
3. It is very labor intensive to clean up after the fire has been extinguished.

Aerosol

Mainly used as individual elements or elements combined into one structural network. It is recommended for use as autonomous fire extinguishing systems in cottages, country houses, and summer cottages.

They can be used not only permanently indoors, but also in transport in the engine compartments of railway trains, sea vessels or large cars.

Smoke removal units

They are divided according to the method of functioning. Passive installations consist of partitions installed to block ventilation ducts. Active smoke removal systems use special electric motors and exhaust hoods to study indoor smoke and reduce oxygen concentrations. Moreover, for this purpose both your own ventilation shafts and the ducts of the ventilation and air conditioning system can be used.

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 of 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.

The requirements for a non-addressed system are 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. They install alarms in buildings with a larger area, more than 1000 m2. 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). They 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 Fire Safety Authorities, as well as maintaining automatic fire alarms. The time to carry out the work is no more than a month (depending on the area of ​​the structure).

Carrying out work:

1. Laying cables according to system requirements.
2. Installation of low-current networks.
3. Installation, connection of touch sensors.
4. Installation of the control panel (at the customer’s request in the specified room).
5. Uninterruptible power supply connection.
6. 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:

1. Checking the correct operation of individual elements and the entire complex.
2. Adjusting APS settings.
3. Repairing damage.
4. Repair and maintenance of power transmission connections.
5. Carrying out preventive work.

Automatic fire alarm is a complex warning system. 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.

All key types of fire alarms are designed for the sole purpose of transmitting information about the occurrence of a fire to the fire department as quickly as possible. Improved systems are capable of remotely activating initially configured fire extinguishers, signaling the start of evacuation of people, and notifying auxiliary control centers about a fire.

The article was prepared with the support of the site https://www.nva-center.ru/ Security services from private security companies - “NVA-Center”.

Modern fire alarm system, regardless of its size and type, consists of the following components:

• Detectors are a special class of sensitive detectors needed to detect a fire by analyzing environmental characteristics, such as smoke, increased temperature;
• receiving and control devices are necessary for collecting and analyzing information obtained by sensors;
• executive-peripheral devices – insulation monitoring, sirens, control panels, relays.

Central control elements may also be included, such as fixed panels, computers with special software.

Detectors

Smoke sensors react to the formation of exhaust gases or combustion products in the controlled area. False alarms occur when moisture or dust gets into them.

Thermal devices detect changes in temperature in a particular room; they are integral and threshold. The latter are adjusted to a specific temperature range, upon reaching which a signal is triggered. The integral type works out the rate of temperature change; it is triggered when this indicator increases.

Fire detector

Gas types of fire alarm sensors analyze the chemical composition of the air; if components specific to smoldering or burning are detected, an alarm is triggered. The devices do not react to moisture and dust, are highly efficient, and are usually installed in ventilation.

Light detects spectrum fluctuations characteristic of flames. They operate in the ultraviolet spectrum.

Combined sensors combine the functions of smoke and heat. Moreover, experts working in the field of fire warning emphasize that heat detectors respond more quickly in critical situations.

Reception and control devices

Reasons for their classification:

1. By appointment - security and fire fighters, managers, firefighters.
2. According to the specifics of communication - radio channel, wired.
3. According to climatic characteristics - for cold and warm rooms.
4. When connecting an auxiliary power source – external, built-in.
5. According to the level of information content – ​​2, 5, more than 5 available types of messages.
6. According to the design of the train - loop, radial.
7. By the number of loops (this indicator characterizes the information capacity) - up to 5, up to 20, up to 100, respectively, low-informative, medium and high-informative.
8. According to the method of activating the standby mode - group, individual, combined.
9. Specialized devices intended for installation in hazardous areas are placed in a separate segment.

These are the main control components of fire alarm systems; they monitor the status of the loops, receive data from detectors and transmit them to the central control panel. Systems designed to operate in stand-alone mode also control automatic extinguishing and smoke extraction.

Peripheral actuators

Here they highlight:

• relay modules are responsible for providing functionality in automatic mode;
• remote controls;
• sound and light annunciators are necessary to notify people of an emergency;
• insulation control – designed to maintain system functionality in the event of a short circuit.

With a comprehensive design of the fire alarm system, all types of executive peripheral devices are connected to the control and receiving link and equipped with a separate housing.

The notification can be light and sound, speech, sound - the type depends on the height of the ceilings, the number of floors and rooms, and the area of ​​the building. Mandatory components are illuminated signs illustrating exit routes.

Types of security and fire alarms (FS)

Currently, 3 types of fire alarm systems are being actively implemented at facilities - non-addressable, addressable, and addressable-analogue. They differ in the operating principle and the specific installation in the building.

Unaddressed

They are distinguished by their simplicity of design; the devices activate certain algorithms in accordance with the signals received from the detectors. Inexpensive signaling devices with a primitive circuit are usually used here; they recognize the conditions of fire, open circuit, and short circuit. Budget devices require a large number of cables during installation; the latter are usually placed in metal conduits and hidden in the walls.

Address

The receiving and control equipment receives information from all sensors distributed in the serviced premises; they read the characteristics of the surrounding space. Control devices analyze the dynamics of changes in these parameters, on the basis of which a conclusion can be made about the occurrence of a fire - an appropriate signal is given.

A characteristic feature of the system is the fact that the fire alarm signal does not arise as a result of the operation of a separate sensor, but is a consequence of the analysis of the receiving and control equipment (the latter takes into account information from all detectors). Each alarm device has its own address, which is involved in the data exchange protocol, so control devices accurately identify dangerous areas and quickly respond to a threat.

Addressable analog

This is the most optimal and common solution. Their main difference from addressless alarms is that to process information and make decisions about the occurrence of an emergency situation, it is not the detector itself that is used, but a receiving and control circuit. The latter is necessary to perform the following functions:

• continuous receipt of information from sensors;
• data processing;
• comparison of the obtained data with the declared threshold values;
• sounding the signal based on information received from different types of detectors.

As a result, the number of false alarms is minimized, the exact location of the fire is identified, and the signal is sent without a time delay.

What to choose depending on the room?

According to generally accepted regulatory documentation, the priority of equipping an object with a fire alarm is determined first, depending on its type and purpose.

Types of premises in accordance with the need for security guards:

Selection of fire safety sensors according to the type of room:

When choosing a fire alarm system, it is important to contact a competent specialist: industry requirements are constantly becoming more stringent, so only a professional, taking into account the features of the facility, can design the safest possible scheme.

The first stage of classification of alarm systems is by purpose. The most famous:

• security;
• fire department;
• automotive.

Security fire alarm (FS) is designed to detect factors that can lead to property damage or threaten the life and health of people.

Modern security systems are mostly automatic. They do not require human intervention to operate. You can even automate the process of taking and withdrawing. For this purpose, there is, although not everywhere, the option of arming an object on a schedule.

To be fair, it must be said that it is rarely used. Firstly, there are practically no enterprises that start and finish work exactly at the same time. Secondly, it is more convenient (more reliable) for the owner to visually check the condition of the alarm system and make sure there are no malfunctions.

Naturally, people react to sensor activation. But even here, the “smart system” is capable of independently taking certain actions. These include: automatic activation of fire extinguishing, smoke removal, warning and evacuation control in case of fire.

Automatic security and fire alarm systems are provided with uninterruptible power supply. If there is no voltage in the electrical network, it must operate in standby mode for at least 24 hours.

TYPES OF SECURITY ALARMS

Depending on the method of responding to an alarm, a security alarm can be:

• with output to the centralized security console (CSC);
• autonomous.

It is customary to classify GSM signaling as a separate category, but this is not always correct. The state of the fire alarm system can be monitored by both the central monitoring station operator and the owner of the protected facility using the GSM module. In the latter case, it will be considered autonomous, even if the owner independently responds to alarm notifications.

True, the above classification was formed when there was no cellular communication, therefore, taking into account today’s realities, it makes sense to distinguish three types of security: autonomous, with output to the security console or the owner’s mobile phone.

Regardless of the notification method, security systems can be wireless or wired based on the type of information transmission. In this case, these methods are used both for the object part and for remote communication with the console.

Types of alarm sensors.

Sensors (detectors) must be installed at the protected facility, which are used to detect attempts at entry or fires.

Obviously, sensors are divided into:

TYPES OF FIRE ALARMS

All fire protection systems are usually divided into three types:

• threshold;
• targeted survey;
• addressable analog.

The features and operating principle of each of them are described on this page. They are listed in order of increasing complexity, respectively options, including information content.

It is impossible to say which is better - it all depends on the category of the object. For a small office or store, a threshold fire system is quite suitable. For a shopping and entertainment center, it is necessary to install an ADDRESS APS.

FIRE ALARM TECHNICAL EQUIPMENT

First of all, security funds are classified according to their purpose:

• sirens;
• Power supplies.

In addition, security systems can use readers, code keypads, and other control and management tools.

Wired and wireless technologies have already been discussed. It is worth mentioning the classification of detectors by purpose. For a security alarm, these will be detection sensors:

• movements (volume);
• breaking of building structures (vibration);
• breaking of glazed surfaces (acoustic or sound);
• opening (magnetic contact).

For fire protection systems, detectors are produced that can respond to smoke (smoke), heat, and open flame.

Receiving control devices (RCDs) monitor the status of detectors and generate signals that determine their status. The main characteristics of the PCP are:

Information capacity– number of controlled loops, zones or sensors.

Information content– the number of generated notifications depending on the state of the loops. There should be at least two of them: “normal”, “alarm”. In practice, devices display information about the status of each loop. In addition to the above, notifications “armed”, “disarmed”, “fault”, etc. can be displayed.

Signal lights- these are lamps; LED modules; light indicators indicating the exit, direction of evacuation routes, etc. TO sound annunciators include sirens and loudspeakers.

For alarm systems, uninterruptible ones must be used. Their power should be 10-20% higher than the total power of the equipment connected to them.

The fire alarm system is a set of technical means united under common control. The core of the system can be a receiving control device (control panel) or a computer with special software installed.

The security system can be integrated with other security systems:

• access control (ACS);
• or smart home equipment.

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The value of fire alarms for any facility is great, because it can even be expressed in the number of lives saved. Nowadays, there are several main types of fire alarms, which are complex systems:

• threshold;
• targeted survey;
• addressable analog.

How does a threshold fire alarm work?

This system has several sensors. Each of them is called a detector. All detectors have a preset response threshold. When it comes to a heat detector, it is triggered when a preset ambient temperature is reached. This sensor provides a corresponding signal to the fire alarm controller or processor. If the temperature has not reached this threshold, the detector will be “silent”.

IMPORTANT! A distinctive feature of this system is the radial type of signaling cable topology.

This means that from the central panel from which control is carried out, wire loops to the detectors extend in different directions. Sometimes they are called rays. As a rule, up to 20–30 detectors are included in one beam, and when one of them is triggered, the central panel can display only the number of the beam where the alarm signal passed.

• low price of equipment

Disadvantages of the system:

• it is impossible to control the performance of sensors;
• relatively low information content of signals coming from sensors

Area calculation table

How does addressable interrogation fire alarm work?

Addressable polling fire alarm differs from threshold fire alarm in the type of communication between the central panel and the detectors. The main panel in the threshold system “awaits” the signal that comes from the detector when the state to which it must respond changes. In an addressable polling system, the central panel itself, at certain intervals, “interrogates” all fire detectors one by one to find out what their status is at the moment.

Addressable interrogation fire alarm system

This fire alarm algorithm helps to monitor the status of the sensors entrusted to it. Types of signals received from the sensor:

• "Normal condition";
• “Sensor malfunction”;
• "Fire in the premises";
• "No sensor."

At the same time, fire plumes have a ring rather than a radial architecture.

Advantages of the system:

• good price-quality ratio;
• greater information content of messages received from sensors;
• precise control over the performance of detectors.

Disadvantages of the system:

• later fire detection than with a threshold system.

However, this delay is expressed in seconds, and during fire evacuation, minutes are more important.

How does an analog addressable system work?

Fire alarms are currently the most functional. They have all the advantages that distinguish the systems listed above. In addition, there are a number of its own advantages.

The main one is the type of decision-making. What is the condition at the facility is assessed by the control panel itself, but not by the detector. The main panel of this fire alarm system is a complex device that produces continuous dynamic communication with each of the connected detectors. The sensor receives and analyzes the values ​​received from the panel and compares them with the state of the room. The panel makes the final decision based on the results of processing the response from the sensors.

Let's say thermal sensors constantly send ambient temperature values ​​to the panel, and the panel itself monitors the value of this value, as well as the dynamics of its change.

This algorithm of fire alarm operation makes it possible to identify sources of fire in the early stages. This allows you to prevent damage that could be caused by fire in a timely manner.

Advantages of the system:

• early detection of flames or smoke in premises;
• savings on installation work and consumables;
• monitoring the performance of fire detectors;
• compensation of sensor sensitivity.

Disadvantages of the system:

• high cost of equipment.

Integrated Systems

If you integrate a fire alarm into a comprehensive security system for a room or building as a whole, this will bring even more successful completion of the task of evacuating people and extinguishing fires.

When installing a fire alarm, it makes sense to integrate it into other security systems of the facility. For example, in a security circuit. This is especially important in order to ensure a quick response to a fire message, or to a signal received from fire alarm sensors. This way, you can organize a calm, without panic, evacuation of company personnel, not only by warning about a fire, but also by opening all the doors and turnstiles for unhindered access of people to the street. This way, it is possible to provide favorable conditions for eliminating any emergency situation that arises at the facility.

Integrated Systems

As soon as a fire is reported, the following actions are performed in the area where the fire is detected:

• standard ventilation is turned off;
• the smoke removal system starts working instead;
• the power supply to the facility is turned off, excluding the alarm system and fire extinguishing systems;
• emergency lighting is activated.
• the light indication is turned on, indicating the routes and exits for personnel evacuation;
• emergency exits for evacuation are unlocked;
• The warning system turns on.

It turns out that the integrated fire alarm system becomes an integral part of the entire security system of the building. With such integration, issues of interaction between all subsystems present in the building must be resolved. And most importantly, it is possible to avoid panic among the people in the room, which is very important for organizing a quick and safe evacuation.