Installation of sound and light alarms. Light and sound annunciator

The purpose of this article is to acquaint designers, installers and integrators of warning systems, sound systems, public address systems with the basic principles and features of electroacoustic calculation. The main attention in this article is paid to the peculiarities of the arrangement of voice annunciators (loudspeakers) in closed protected premises.

One of the main tasks to be solved in the process of electro-acoustic calculation performed at the initial stage of designing fire warning systems - SOUE is the task of selecting and arranging voice annunciators (hereinafter referred to as loudspeakers). Loudspeakers can be installed both in open areas and in closed (protected) premises. The purpose of this article is to propose and justify options for the optimal placement of voice annunciators (hereinafter referred to as loudspeakers) in closed (protected) premises.

In enclosed spaces, it is recommended to install internal loudspeakers, as the most optimal in terms of parameters and quality. Depending on the configuration of the room, these can be ceiling or wall types. Proper placement of loudspeakers allows you to ensure even distribution of sound in the room, therefore, to achieve good intelligibility. If we talk about sound quality, it will be determined mainly by the quality of the selected speakers. So, for example, when using ceiling loudspeakers, it must be taken into account that the sound wave from the loudspeaker propagates perpendicular to the floor, therefore, the sounded area at the height of the listeners' ears is a circle, the radius of which is taken equal to the difference between the height of the installation (mounting) of the loudspeaker and the distance to the mark 1.5 m from the floor (according to regulatory documentation). In most tasks for calculating ceiling acoustics, sound waves are identified with geometric rays, while the directivity pattern (DN) of the loudspeaker determines the parameters (angles) of a right-angled triangle, therefore, to calculate the radius of a circle (leg of a triangle), the Pythagorean theorem is sufficient. For uniform sounding of the room, the loudspeakers should be installed so that the resulting areas touch or slightly overlap each other. In the simplest case, the required number of loudspeakers is obtained from the ratio of the sounded area to the area sounded by one loudspeaker.

One of the main parameters that needs to be determined in the calculations is the Loudspeaker Chain Spacing. It will be determined by the size of the room, the height of the loudspeakers and their directivity pattern (SPD).

When arranging wall-mounted loudspeakers in corridors along one wall, the recommended spacing is:

• excluding reflections from walls:

  (Spread spacing, m) = (Corridor width, m) x 2

• taking into account reflections from the walls:

  (Spread spacing, m) = (Corridor width, m) x 4

When arranging wall-mounted loudspeakers in rectangular rooms on two walls in a checkerboard pattern, the spacing step is:

When placing wall-mounted loudspeakers in a rectangular room on two walls, the spacing step is:

Primary requirements

Here is the main requirement of regulatory documentation (ND):

The number of sound and speech (loudspeakers) fire alarms, their placement and power must ensure the sound level in all places of permanent or temporary stay of people in accordance with the norms of this set of rules.

Installation of loudspeakers and other voice annunciators (loudspeakers) in protected premises should exclude concentration and uneven distribution of reflected sound.

Voice annunciators (loudspeakers) should be located in such a way that at any point of the protected object where it is required to alert people about a fire, the intelligibility of the transmitted speech information is ensured.

The design of warning systems is accompanied by the performance of an electro-acoustic calculation (EA). The consequence of a competent EAR is optimization - minimization of technical means, improving the quality of perception. The quality of perception, in turn, is characterized by sound comfort for background music and intelligibility for speech messages. The criterion for the correctness of the EAR is the requirements of regulatory documentation (RD), which can be conditionally divided into:

• requirements for a voice annunciator (loudspeaker);
• requirements for the levels of sound signals;
• requirements for the placement of voice annunciators (loudspeakers).

It should be noted that the RD sets out only the necessary (minimum) requirements, while sufficient (maximum) requirements are provided by the availability of competent methods, and in their absence, by the literacy and responsibility of the designer.

Speaker Requirements

The following requirements are set out. Sounders must provide a sound pressure level such that:

The sound signals of the SOUE provided a total sound level (the sound level of constant noise together with all the signals produced by the annunciators) of at least 75 dBA at a distance of 3 m from the annunciator, but not more than 120 dBA at any point of the protected premises.

This paragraph contains two requirements - the requirement for minimum and maximum sound pressure.

Minimum sound pressure

The loudspeaker must provide a (minimum) sound level at a distance of 1 m from the geometric center:

Maximum sound pressure

Let's give the definition of the calculated point:

The calculated point (RT) is the place of possible (probable) location of people, the most critical in terms of position and distance from the sound source (loudspeaker). The RT is selected on the design plane - an (imaginary) plane drawn parallel to the floor at a height of 1.5m.

Requirement for audio signal levels

The basic requirement for the (necessary) sound signal level is set out in the RD:

Sound signals of the SOUE should provide a sound level of at least 15 dBA above the permissible sound level of constant noise in the protected room. Sound level measurement should be carried out at a distance of 1.5 m from the floor level.

Placement Requirements

The main requirement for the placement of loudspeakers is set out in the RD:

Installation of loudspeakers and other voice annunciators (loudspeakers) in protected premises should exclude concentration and uneven distribution of reflected sound.

Voice annunciators (loudspeakers) should be located in such a way that at any point of the protected object where it is required to alert people about a fire, the intelligibility of the transmitted speech information is ensured.

Taking into account the basic characteristics of loudspeakers

According to , the arrangement of loudspeakers is part of the organizational measures performed in the design of the SOUE and is called electro-acoustic calculation. The most relevant is not just the placement, but the optimal placement of loudspeakers, which allows minimizing the amount of calculated resources (time) and material resources.

Ways of arranging loudspeakers are closely related to their design features. The most generalized is the following classification:

• by execution;
• by design features;
• by characteristics;
• according to the method of matching with the amplifier.

Accounting for the type and design features of loudspeakers

By design, loudspeakers can be divided into internal and external. A characteristic feature of the internal design is the IP protection class. For internal loudspeakers, IP-41 is sufficient, for external loudspeakers - not lower than IP-54. For premises, primarily for the sake of economy, internal loudspeakers are used.

Depending on the tasks to be solved, loudspeakers of various designs can be used. So, for example, depending on the configuration of the room, ceiling-mounted or wall-mounted loudspeakers can be used. For scoring open areas, horn loudspeakers are used, due to their characteristics, protection class, high degree of sound directivity, high efficiency.

The specifics of accounting for the main parameters of loudspeakers

To implement a competent placement of loudspeakers, we need the following characteristics (basic parameters) of the loudspeaker:

Loudspeaker Sound Pressure Calculation

Loudspeaker loudness cannot be measured directly, so in practice it is expressed in terms of sound pressure levels, measured in decibels, dB.

The sound pressure of a loudspeaker is determined both by its sensitivity and by the electrical power supplied to its input:

Speaker sensitivity P 0 , dB (loudspeaker sensitivity is sometimes called SPL from English. SPL - Sound Pressure Level) - the sound pressure level measured on the working axis of the loudspeaker, at a distance of 1 m from the working center at a frequency of 1 kHz at a power of 1 W.

Loudspeaker power

There are several main types of power:

Loudspeaker Rated Power– electrical power at which the nonlinear distortion of the loudspeaker does not exceed the required values.

Loudspeaker power rating- is defined as the highest electrical power at which the loudspeaker can work satisfactorily for a long time on a real sound signal without thermal and mechanical damage.

Sinusoidal power is the maximum sinusoidal power at which the loudspeaker must operate for 1 hour with a real music signal without suffering physical damage (cf. maximum sinusoidal power).

In general, the value specified by the loudspeaker manufacturer should be used as the power parameter.

Basic calculations

Sound pressure reduction with distance

To calculate the sound pressure level at the calculated point, it remains to determine one more important parameter - the magnitude of the decrease in sound pressure depending on the distance - divergence, Р 20 , dB. Depending on where the loudspeaker is installed - indoors or outdoors, different formulas (approaches) are used.

Calculation of sound pressure level in RT

Knowing the parameters of the loudspeaker - its sensitivity - P 0, dB, the input sound power P W, W, and the distance to the RT, r, m, we calculate the sound pressure level L 1 , dB, developed by it in the RT:

Sound pressure in the RT with simultaneous operation of n loudspeakers:

Effective Range Calculation

The effective sound range of the loudspeaker is the distance from the loudspeaker to the point where the sound pressure does not exceed the value of (LN+15) dB:

Effective sound range (loudspeaker) D, m, can be calculated:

Working with Templates

Let's divide all loudspeakers into three main classes, differing in the direction of emission of sound energy.

Ceiling– loudspeakers, the sound energy of which is directed perpendicular to the calculated plane (floor) [Sound energy is directed along the working axis of the loudspeaker].

wall– loudspeakers whose sound energy is parallel to the calculated plane (floor).

Horn- loudspeakers, the sound energy of which is directed at a certain angle to the calculated plane (floor).

Under patterns we will understand the geometric area, which is the projection of the sound field of the loudspeaker onto the calculation plane:

• for ceiling speakers a circle;
• for wall - sector;
• for horn - ellipse.

The loudspeaker is a wideband device. For the lower frequency of the regulatory range f=200Hz, the loudspeaker can be considered as a sound emitter of a spherical wave. As the frequency increases, the speaker pattern begins to narrow and concentrate inside the spherical cone with the opening angle [Angle between the generatrix of the spherical cone (coverage angle)], determined by the value of the SRP. This representation does not fully correspond to the established practice, according to which the sound field at the loudspeaker output is usually approximated by a semi-ellipse. In it is shown that for (statistically average) SDN=90 0 the quantitative estimates for the cone and ellipse are the same.

Estimation of the effective area sounded by loudspeakers of various types can be associated with the problem of finding the area formed by the intersection of a given spherical cone with the working plane. Let's use the well-known geometric representation, according to which the result of the intersection of a plane and a cone at different angles are various elliptical surfaces - a hyperbola, a parabola, an ellipse and a circle, Fig.1.

Hyperbola is obtained as a result of the intersection of a cone and a plane intersecting one of its generators.

Parabola is obtained as a result of the intersection of a cone and a plane parallel to one of its generators.

Ellipse is obtained as a result of the intersection of a cone and a plane intersecting both of its generators.

A circle is obtained as a result of the intersection of a cone and a plane parallel to its base.

Definition 1

The effective area sounded by the loudspeaker is the area on the working plane within which the sound pressure remains within the limits determined by the loudspeaker radiation pattern.

Let us calculate the effective areas sounded by different types of loudspeakers.

Loudspeaker placement

The problem of optimal placement of loudspeakers can be related to the results obtained in the previous chapter. Let's give a definition:

Definition 2

Loudspeakers must be placed in such a way that any potential design point must fall within the limits covered by the radiation pattern of the nearest loudspeaker.

In the previous section, we got three basic geometric shapes [Which we will later use as tracing paper (figures) to fill (uniformly cover) the surface] - a circle, a sector and an ellipse. The placement problem can be reduced to a uniform coverage [Cf. the problem of “tiling” the surface in mathematics] of the entire working plane.

Accounting for reflections

In practice, the placement of loudspeakers is carried out taking into account reflections from surfaces [Accounting for reflections is very relevant. It should be noted that the so-called. direct sound (sound energy received by the listener in the first 50ms) consists of 80% reflected energy (the so-called primary reflections), and the clarity of perception (which, by the way, as well as intelligibility is not taken into account in the standards) directly depends on the share of the direct diffusion energy of an enclosed space. Within the framework of the elementary EDA (see the previous chapter), it is proposed to take into account no more than one reflection (cf.)].

We will take into account reflections based on the geometric ray theory, in which sound energy is identified with a geometric ray reflected from the surface at the same angle and in the same plane, Fig.2.

When it hits a surface, some of the sound energy is lost. The proportion of absorbed sound energy P abs, dB, can be determined by knowing the absorption coefficient K abs of the surface:

When considering reflections, it is necessary to check the following boundary condition, Fig. 2:

If condition (8) is met, the placement of the loudspeakers can be carried out taking into account reflections.

Most surfaces such as parquet, laminate, wood, concrete practically do not absorb [So, for example, for wooden sheathing at a frequency of 4 kHz, K absorption = 0.11, P absorption = 0.5 dB]. In further examples of speaker placement, as a simplification, we will assume that the sound energy is completely reflected from the surface.

Critical Speaker Spacing

From Fig. 3 it can be seen that the sound in the RT comes from 2 loudspeakers. Knowing the speed of sound in air v=340m/s and the delay time t=0.05s, it is easy to obtain the critical distance Rcr, m, at which the echo becomes possible: Rcr = vt = 340*0.05=17m, where v is speed of sound propagation in air (340m/s).

From Fig.3, the path difference should be:

Depending on the directivity of the loudspeakers and their SDN, the spacing step can be determined geometrically:

Room classification

We will consider two main types of premises:

• corridors;
• rectangular rooms.

By corridors we mean narrow extended rooms with ratios of length a (m) and width b (m): a/b≥4.

Rooms with a/b ratios

Let's divide the rooms into the following groups:

• corridors with low ceilings (height h ≤ 4m);
• corridors with high (h > 4m) ceilings;
• corridors are narrow (b ≤ 3m);
• wide corridors (b > 3m and h ≤ 6m);
• medium rectangular rooms (b > 6m and b ≤ 12m);
• voluminous rectangular rooms (b> 12m).

Comment:

To determine the numerical value of the proposed coefficients (b, h), the average value of the effective sounding range D (m) was used, which for P db =95dB, VL=60dB, will be ~ 10m and SRP=90 0 .

How speakers are placed, with or without reflections, is determined by two factors:

• ceiling height (with high ceilings, the reflection effect can be ignored);
• type of reflective surface.

Corridors with low or high ceilings

The concepts of “low / high” ceilings will be considered in relation to the ways in which ceiling speakers are placed.

When placing loudspeakers on low ceilings, it is desirable to take into account reflections from the floor. In this case, the following criterion is used to determine the numerical value of the speaker spacing:

The sound energy emitted by the ceiling loudspeaker should 'finish' to the floor and, reflected from it, to the 'calculated plane'.

When placing loudspeakers on high ceilings, reflections from the floor can be ignored or criterion (8) must be checked.

Narrow or wide corridors

The concept of “narrow / wide” corridors will be considered in relation to the methods of placing both ceiling and wall speakers. In both cases, we will have to take into account reflections from the floor or walls.

For wall speakers

To determine the numerical value of the spacing of the wall loudspeakers in the case of reflections, we will use the following criterion:

The sound energy emitted by the wall speaker should “finish off” to the opposite wall and, reflected from it, to the wall on which the speaker is installed.

When placing loudspeakers in wide corridors, reflections from walls can be ignored or criterion (8) must be checked.

For ceiling speakers

To clarify the meaning of narrow/wide corridors in the case of ceiling loudspeakers, consider the concept of a loudspeaker chain.

Figure 4 shows a wide corridor containing two chains of ceiling speakers.

The number of chains, K c, pcs, will be determined from the ratio:

Consider examples of loudspeaker placement for different types of premises (cases) and the conditions for determining the spacing W, m.

Ceiling speaker placement

Placement of ceiling speakers in corridors with high ceilings without taking into account reflections from the floor

Placement of ceiling loudspeakers in corridors with high ceilings without taking into account reflections [As noted above, due to the height of the ceilings or the presence of reflective surfaces] from the floor, should be carried out in steps, Fig. 5:

With SDN=90 0, R=h–1.5:

Test condition 1

The loudspeaker, taking into account the SDN, must reach the working plane.

With SDN=90 0:

Placement of ceiling speakers in corridors with low ceilings, taking into account reflections from the floor

It is permissible to place ceiling loudspeakers in corridors with low (less than 4m) ceilings, taking into account reflections (from the floor) in increments, Fig. 6:

Arrangement of wall-mounted loudspeakers placed along one wall, ignoring reflections

Placement of wall loudspeakers in (wide, over ~3 m) corridors, with placement along one wall, without taking into account reflections, should be carried out with a step W = 2R:

where ShK is the width of the corridor, Fig.7.

With SDN=90°, R=ShK we have W=2ShK.

Test condition 3

Effective range, for arbitrary SDN:

For SRP= 90°:

Let us write down the criterion for determining the effective range, taking into account the installation height of the loudspeaker, H, m. For an arbitrary SRP:

Arrangement of wall-mounted loudspeakers placed along one wall, taking into account reflections

Arrangement of wall loudspeakers in (narrow, up to ~3 m) corridors, with placement along one wall, taking into account reflections, it is permissible to carry out with a step W=4R, where R is calculated by formula (16), Fig.8.

With SDN=90°, R=ShK we have W=4ShK.

Test condition 4

The loudspeaker, taking into account the SDN, should finish twice to the opposite wall, taking into account the SDN.

Effective range, for arbitrary SDN:

For SRP= 90°, excluding absorption:

Considering the installation height, see formula (18).

Placement of wall-mounted loudspeakers in rectangular rooms, staggered along two opposite walls

The placement of wall-mounted loudspeakers in medium rectangular rooms, with the possibility of placement along two opposite walls, is desirable to be carried out in a checkerboard pattern with a step of W = 2R:

where b is the width of the room, Fig.9.

With SDN=90°, R= b we have W=2b.

Test condition 5

The loudspeaker, taking into account the SDN, should reach the opposite wall.

Effective range, for arbitrary SDN:

For SRP= 90°:

Arrangement of wall-mounted loudspeakers in rectangular rooms, placed along two opposite walls

Wall loudspeakers in rectangular rooms of a large area can be placed on opposite walls, in any order with a step determined by half the distance to the opposite wall, b / 2 (m) W = 2R.

Where b is the width of the room, Fig.10.

With SDN=90°, R= b we have W=b.

Test condition 6

The loudspeaker, taking into account the SDN, should penetrate half the distance to the opposite wall, Fig. 10.

Effective range, for arbitrary SDN:

For SRP= 90°:

The installation height is taken into account similarly to formula (18).

Placement of loudspeakers in rooms with a complex configuration

The placement of loudspeakers in rooms with a complex configuration is carried out as follows. The sounded (designed) room is analyzed, divided into separate sections, for each of which the appropriate arrangement scheme is selected, from the above. The main task, in this case, is reduced to the optimal docking of individual sections.

Literature

1. Code of Rules SP-3-13130-2009 of 2009 “Fire safety requirements for sound and voice warning and evacuation management”.
2. Kochnov O.V. “Peculiarities of designing warning systems” (Murom, publishing house Kovalgin, 2012).
3. Kochnov O.V. “Design of warning systems” (Tver 2016, Volume 1).

The light and sound annunciator is able to become a convenient means of transmitting light and in the event of emergencies in buildings of various types and purposes. Light and sound type annunciators provide timely signals about the beginning of an evacuation, remaining active throughout the day, operating from a standard electrical network.

Applications

Various models and modifications of light and sound annunciators are actively used to ensure security at industrial facilities, in retail establishments, entertainment and public areas.

Each device must necessarily correspond to the features and purpose of the room in which it is installed. Usually, a suitable light and sound annunciator is selected based on the level of noise that exists in the room. The type of activity of the people who are in it is also taken into account.

Operation features

Before installing a light and sound annunciator, it is necessary to determine the mode in which it should work. This can be a general, simplified or special mode of operation. The latter option is most often used at security posts and in medical institutions, in control rooms, when the fire alarm system is under the control of specially trained personnel.

In the standard mode, the sirens work in public, residential and rented premises. To ensure comprehensive security, several devices are mounted on opposite walls, connected to an alarm system and operate from a conventional power supply.

Mounting

The light and sound annunciator (220V) can be connected to the security system either by soldering or by the standard, default screw method. Connection of input and output wires by means of the siren terminals is carried out by their duplication.

The operation of the siren in standby mode involves installation, in which communication control is performed by connecting wires to the end element. Typically, such an element is a resistor with a diode. When installing sirens, external connection of diodes is unacceptable.

Types of sirens

If we talk about the possibilities of operation and design differences, then there are:

• external type of annunciators that provide security in open areas;
• indoor sirens, widely used for indoor use.

Regardless of the type, a device such as a light and sound annunciator can be installed at facilities with fire and security alarms, not only to give light and sound signals during the evacuation of people, but also, if it is necessary to give certain signals to personnel.

Standard and combined models

Despite the relatively limited functionality, which is dictated by the purpose of standard sirens, at present there is a sufficient number of various modifications of devices for this purpose. Modified annunciators are designed for use in the most innovative integrated security systems and modern fire alarms.

Among the main advantages that distinguish the light and sound combined siren, it is worth highlighting the modern design, the availability of conditions for installation both outside and inside the premises, as well as the possibility of issuing sound and light signals simultaneously. This, in turn, becomes extremely important for ensuring safety at sites with a high level of noise and smoke in the premises.

Light and sound annunciator: price

The cost of light and sound annunciators of domestic production refers to the average price range. The price of the simplest models varies from 70 to 150 rubles. The cost of combined and modified devices can reach 350 rubles, which is fully consistent with their functionality.

Naturally, the same light and sound annunciator may differ in different prices depending on the pricing policy of a particular retail chain. However, for most consumers, the price of domestic and imported devices is still more than acceptable. Therefore, such security systems are available to the widest range of interested buyers.

Light and sound annunciator "Mayak"

If we talk about the most popular models available to the domestic consumer, then light and sound devices of the Mayak brand come out on top here. Today, such relatively inexpensive, really reliable, functional and durable systems are widely used in domestic industrial, commercial, entertainment, exhibition, and public facilities. If necessary, fire alarm systems in residential premises can be equipped with Mayak brand annunciators.

Lighthouse annunciators do an excellent job with their main task - notifying people about an emergency situation with the help of signals that can simultaneously affect a person's vision and hearing. The devices of the brand "Mayak" cope with this task perfectly, which is confirmed by practice and numerous reviews of specialists.

In the event of an emergency, devices of this category light up with a bright pulsating light, which illuminates a special alarm or direction indicator. The light signal is accompanied by a loud, clearly audible sound siren in conditions of increased noise. Currently, such annunciators are in demand not only if it is necessary to ensure security at enterprises, but also among individuals.

However, giving preference to light and sound annunciators of the Mayak brand, you need to understand that for their effective operation it is necessary to select the correct type of device that corresponds to the features of the existing alarm system. It is also necessary to pre-calculate their sufficient number, starting from the conditions and features of the room. Therefore, the choice of annunciators should be approached wisely, preferably relying on the advice and opinions of experienced professionals.

Modern warning systems are complexes of equipment, the correct operation of which makes it possible to guarantee the timely supply of alarming information and the organization of an effective process of evacuating people. Depending on the characteristics of the object, warning systems can be quite simple and built using a minimum number of devices, or they can be a complex and multi-component set of equipment. However, regardless of the complexity and type of SOUE, the installation of annunciators is an integral part of any warning system. According to the requirements of SP 3.13130.2009, the installation of sound annunciators is mandatory for, installation of light annunciators -. And this is quite justified, because fairly simple and low-cost annunciators can effectively convey information about a fire and indicate the nearest evacuation routes, and therefore save people's health and lives. There are many more standards for installing fire alarms. , prescribed in the regulatory documents and must be observed. All these requirements, as well as the key features of each type of annunciators, will be considered further.

Most often, the installation of sound annunciators is carried out in structurally simple buildings belonging to the first type of SOUE, or in separate rooms of buildings with the SOUE system of types 2-5, which do not imply the possibility of permanent residence of people. As a rule, in such cases, there is no need for additional devices and the purpose of the system is to give an audible signal informing about the need to immediately leave the premises. It is possible to ensure the correct operation of the sound notification only by observing all the rules and current regulations for the installation of sound annunciators.

Standards for installing sound alarms

1. The sound pressure level at any point in the room should not exceed 120 dBA, but be at least 75 dBA at a distance of 3 m from the siren. When the sound level decreases, a person in the building may not hear the alarm signal, while exceeding the norm leads to a deafening effect and the creation of unnecessary panic during evacuation.

2. The sound level of the warning signal generated at a level of 1.5 m from the floor must exceed the value of the permissible constant noise level by at least 15 dBA. This item allows you to install sounders, taking into account the differences in noise pollution of various buildings and premises.

3. In rooms intended for sleeping, the sound level is measured at the level of the head of a lying person and should be at least 70 dBA and exceed the constant noise level by 15 dBA.

4. Installation of sound annunciators must be carried out taking into account the uniform distribution of sound over the entire area. The concentration of sound at one point and insufficient scoring of others is unacceptable.

5. Annunciators must be fixed exclusively to non-combustible capital structures, because in the event of a fire, combustible walls and ceilings can ignite or collapse along with the annunciators installed on them. Naturally, in this case, the operation of the warning system will be disrupted.

6. Installation of sounders on the wall must be carried out in such a way that the distance from the top of the device to the ceiling is at least 0.15 m, and to the floor - more than 2.3 m. There is a lot of controversy on this point, because the ceiling level declared at the design stage is not always matches the final one. And here the question arises - what to do if the ceiling height is less than 2.45 m and it is simply impossible to provide the necessary installation height for sounders? The answer is very simple - to mount the sirens on the ceiling, while ensuring reliable fastening to a non-combustible base (main ceiling).

Light annunciators in one form or another can be seen in almost any building. These can be simple light annunciators used in combination with sound notification, as well as various light panels with inscriptions or arrows. The installation of light annunciators "EXIT" is mandatory for all types of SOUE (except for the first), light signs for the direction of movement - for SOUE types 4 and 5. Also, in warning systems, special displays are often used to inform about the start of gas and powder fire extinguishing installations and the need to urgently leave the premises. Naturally, the installation of light signs does not solve the problem of warning in general, however, it allows people to focus on the presence of a threat and effectively organize evacuation, directing everyone to the evacuation exits.

Norms of installation of light annunciators

1. Light annunciators must be installed at a height of at least 2 m. This condition guarantees excellent visibility of the device and minimal risk of damage due to accidental mechanical impact.

2. Installation of light indicators "EXIT" is carried out directly above the emergency exits leading outside or to a safe area of ​​the building.

3. The installation of light indicators of the direction of movement is mandatory in corridors longer than 50 m (interval up to 25 m), in places where corridors turn, as well as in all smoke-free stairwells. Additional installation locations are determined by the design organization based on the planning decisions of the building and possible evacuation scenarios.

4. During the stay of people in any auditoriums and demonstration halls, the light indicators "EXIT" installed in them must be turned on.

This type of annunciator combines the capabilities of light and sound annunciators and, as a rule, is used to reduce the amount of equipment and cable routes in order to simplify and reduce the cost of the system. So, if the noise level in the room exceeds 95 dBA or people in it are in noise-protective equipment, SP 3.13130.2009 regulates the combination of light and sound annunciators. In this case, the most appropriate would be the installation of light and sound annunciators. For small premises in which it is necessary to combine light and sound notification, the most appropriate solution would be to install the light and sound annunciator "EXIT" (board). Thus, it is possible to reduce the amount of equipment and cable products, while maintaining all the functionality of the system.

Order the installation of sirens

All work on the installation of sirens must be carried out exclusively by certified specialists with experience in carrying out such work and all the necessary permits. in our company, you will receive high-quality advice, a miscalculation of the cost of work and any additional information, and you will also be able to order high-quality installation and connection of sirens.

The first light and sound annunciators in fire and security alarm systems were used separately. It was associated with the low development of electronic technology and the previous legislation.

Now, in an effort to convey an alarming message to everyone, regardless of their physical characteristics, they began to use a combined light and sound annunciator. They are arranged in such a way that the area of ​​effect covers the entire zone of control.

Advantages and disadvantages of light and sound signaling

Sound and light alarms are installed in public places to warn of a fire and other emergencies. This is necessary to reliably draw people's attention to the incident.

When combining the siren in one device, the cost of the device is reduced, one housing is required instead of two.

If wireless devices are used, then the savings are greater, one battery is required. In addition, less materials (cable, fasteners), labor costs for installation work are used.

The advantage is that do-it-yourself light and sound alarms are very easy to do. It is enough to use a light and sound detector in conjunction with an autonomous motion sensor.

The result is a simple, cheap alarm that will scare off intruders with light and sound, notify security about unauthorized entry to the facility.

Simplicity is good within a small object. When ensuring the protection of large buildings, such a system is unsuitable; multi-zone security systems with an accurate definition of the scene of the incident are needed here.

Application area

Light and sound alarm is an integral element of any security system. In accordance with the law, all premises are equipped with fire detectors and warning devices.

Shopping, entertainment centers, sports facilities, office buildings, museums, theaters have alarm systems, fire fighting devices. No school or hospital is put into operation without a fire alert.

When servicing large buildings with a huge number of rooms, in addition to all kinds of sensors, devices are required that notify a person about an emergency. The most dangerous fire on the ship.

Therefore, all sea and river vessels are also equipped with light and sound warning and fire fighting systems.

Mining, chemical, oil refineries are required to install light and sound alarms.

The principle of operation of the light and sound detector

The essence of the light and sound annunciator is to create a sound of a certain tone and volume, which warns others about a fire or unauthorized access to a protected area. As an additional element, a light detector is used, duplicating the siren with bright flashes.

The device is switched on by a simple connection to the supply voltage through an electronic or relay key, which can be opened from the control panel.

When using an addressable device, the siren and light flashes are triggered by the control unit of the siren upon command from the central console via cable or radio channel.

Design

Depending on the installation location of the device, the detectors are wall-mounted or ceiling-mounted, indoor or outdoor. The body shape is usually rectangular or round.

Super bright LEDs or lamps are used as light sources. The sound signaling device is made on the basis of a piezoelectric transducer or an electrodynamic device.

The case is made of metal, polycarbonate or other plastic, depending on the operating conditions.

To protect against opening, a special contact of unauthorized access is provided. Holes are provided for fastening and entry of power and control cables.

Features of installation of the sound detector

The installation of the siren depends on its type, installation location, and housing type. If a wireless device is used, then it is enough to fix the base of the device, and the remaining elements will be located on the board under the cover.

With a wired power and control circuit, cables will have to be laid in channels or outdoor installation. For street laying, it is better to use corrugated metal pipes.

To protect against atmospheric precipitation, the sirens must be placed under the visor. In large rooms, the devices are positioned in such a way as to ensure visibility and audibility in all areas.

TOP-5 models of sound detectors

System Sensor is the world's leading manufacturer of security and fire alarm devices.

Its products of high quality and reliability, awarded with many prizes, are produced at factories in eight countries of the world, including Russia.

The combined (light and sound) devices CWSS-RB-W7 among the sirens produced by the company have the best price / quality ratio.

The device is powered by DC voltage from 12 to 29 volts. Siren creates acoustic pressure up to 109 dB.

The wide radiation pattern of the light emitter, excellent optics allow you to install the device in any position, regardless of the spatial orientation.

The device provides 32 tones and a red flash.

It has a degree of protection of the housing IP65, which allows outdoor use at temperatures of -25 +70 ⁰С, air humidity up to 96%.

The company "Electrotechnics and Automation" produces a whole line of light, sound and combined annunciators. The Mayak-12-K model is popular.

This is an all-weather device operating at temperatures of -50 +55 ⁰С.

The siren creates an acoustic pressure of 105 dB, consumes 20 mA, as well as the light block.

The device is made in a metal case 2 cm thick.

Mounted on the wall, in the case of outdoor installation, it is necessary to provide a visor to protect against direct rainfall.

It is powered by DC voltage of 12 V, there is a modification for 24 V. The device has a 1-year warranty, a low price, and is in demand.

Light and sound alarm 220 V "Biya-S" is produced by the company "Spetsavtomatika".

The device generates an acoustic pressure of 85 dB and can operate in alarm mode for up to 24 hours. Powered by alternating voltage 220 volts 50 Hz.

The role of the light emitter is performed by an electric lamp with a power of 25 watts. An electrodynamic unit acts as a sound annunciator, it operates at temperatures of -40 +50 ⁰С, air humidity up to 98%.

The manufacturer gives a 2.5 year warranty. The service life is 10 years. Protection against opening is provided.

The company "Spetspribor" produces light and sound annunciators in an explosion-proof housing. They are used in mines, chemical industries and other enterprises of a similar level of danger.

The devices have a metal case in IP67 performance and a siren with a sound pressure of 105 dB. They are powered by a constant voltage of 12 or 24 volts.

Combined annunciator VS-07e-I 12-24 by Eridan is designed to work in the chemical, oil and gas and oil refining industries. Acoustic emitter produces 100 dB, powered by 12/24 volts.

The body is made of aluminum, the cables are enclosed in metal corrugated pipes. It is operated at temperatures of -55 +70 ⁰С.

Conclusion

Fans of making alarms with their own hands should take into account when searching and buying on the Internet that an annunciator and a surface sound detector, for example, Harp IO 329-3, are fundamentally different devices.

The first one informs people about the fire, violation of the security regime, after the second one discovers the fact of this incident.

The burglar sound detector is a glass break detector, and the exit light annunciator is a panel with a corresponding inscription and backlight.

In order not to be confused, be sure to read the technical specifications before ordering equipment.

Video: Light and sound fire alarm

Timely informing about the outbreak of a fire helps to effectively carry out the evacuation of people and begin prompt measures to eliminate the source of fire. This is especially true for buildings in which a significant number of people live or work. For these purposes, alerts are used.

One of the varieties of such equipment is a light and sound annunciator, where light and sound are used to transmit an alarm signal. With its help, fire and security systems are equipped, which are responsible for the prompt evacuation of people in the event of a threat to their lives.

Main functions of the device

A light and sound annunciator is a complex electronic device that sends both visual and audible alarm signals. Almost all modern security and fire alarm systems are equipped with such devices, which are responsible for the prompt evacuation of people when the first signs of danger appear.

As a rule, sirens are installed at the following objects:

• educational and medical institutions;
• retail outlets and entertainment centers;
• catering facilities;
• hotels;
• industrial buildings and structures.

The advantage of light and sound signaling is the use of a duplicated signal to warn of danger. This allows you to attract as much attention as possible when there is a lot of smoke, or when the building is very noisy.

Often devices are placed in an explosion-proof case, which contributes to their uninterrupted operation in fire conditions. There are intrinsically safe models designed for installation in hazardous areas, and devices in the usual version.

Design features

Red and yellow light is used to signal danger in light and sound annunciators, blue and green colors can be additionally provided. The glow can be both flashing and constant. The sound mode and nature of the sound signal may also vary depending on the model of the device.

A modern light and sound annunciator consists of several modules:

• high-strength metal shell capable of resisting aggressive influences;
• a board made of reinforced glass for light informing with inscriptions “exit”, “powder leave”, “do not enter” and others (there may not be any inscriptions);
• a source of sound pulsating signals having a certain sound spectrum and a sound level of at least 85 dB;
• special connectors that make it possible to switch the wiring of the system.

The design of the light and sound annunciator is thought out in such a way that it can continue to work in the mode of extreme and aggressive influences. To prevent unauthorized openings, the device is equipped with a special access contact. There are special mounting holes and openings for power and control cables.

Installation

Due to the extensive warning coverage area, light and sound equipment is most often mounted on walls and other building structures. This allows you to achieve the greatest visual and acoustic coverage of the surrounding space.

It is important to do everything possible so that there are no obstacles in the directions of the sound waves, and the human eye can clearly perceive the inscriptions on the scoreboard or light indication in both natural and artificial lighting conditions.

The specifics of the installation of light and sound signaling equipment is influenced by its type, place of application and type of housing.

Wireless devices are more convenient in this regard: their installation includes a simple mounting of the base, while other parts are on the board under the cover. If the siren is powered by a cable, then special channels will have to be used for its installation. If the alarm is set up outdoors, it is recommended to place the wiring inside corrugated metal pipes. To ensure that the operation of the device is not affected by precipitation, protective visors are used.

Popular Models

On sale light and sound explosion-proof annunciators are presented in a wide range. Considering the fact that a person's life directly depends on their work, it is better to give preference to proven models, with an optimal price / quality ratio. The higher the protective properties of the case, the wider the capabilities of the device, the higher its price, which can reach 8-10 thousand rubles.

Mayak-12-KP

The purpose of this combined fire and security device is to alert people about the danger that has arisen by means of sound and light signals.

Assembly and maintenance work may only be carried out if there is adequate experience.

This light and sound annunciator is not intended for operation in hazardous areas. During installation, it is important to ensure reliable protection of equipment from climatic and atmospheric influences.

Mayak-12-KP has a sound pressure level of 105 dB. The disadvantages of the device is the inability to change the volume level. In cases where the signal strength is not enough, it can be amplified with a howler. The body material is steel. The siren has a compact size and modern design. It is allowed to operate the equipment in temperature conditions from -30 to +55 degrees.

Lightning-12-3

This siren looks like a sign with the word "Exit" on a red or green background. The convenience of this device lies in its ability not only to signal the start of a fire, but also to indicate the direction of evacuation. The beep volume is set to 100 dB.

The collapsible scheme makes it possible to install any inscription on the scoreboard. For the manufacture of the case, polycarbonate is used with a transparent insert in front of acrylic glass.

The correct operation of the light and sound annunciator "Lightning-12-3" is guaranteed at temperatures from -30 to +55 degrees. To simplify installation, the body of the device is provided with special holes. This allows surface mounting on the wall surface. The light source is an LED-type ruler that illuminates the scoreboard on a volumetric scale.

The device requires a 12V or 24V DC power source to function.

For switching with external sources, the siren has a special terminal block.

Visual and light warning can work in parallel or separately, the operating mode of the device is set depending on the operating conditions.

Biya-S

The light and sound type siren of the Biya brand provides an acoustic pressure level of 85 dB, and is capable of continuously sending alarm signals throughout the day.

For power supply, an alternating voltage of 220 V and 50 Hz is used, light signals are sent by an electric lamp with a power of 25 W. Sound notification is provided by an electrodynamic circuit operating at temperatures from -40 to +50 degrees and air humidity up to 98%.