Lab #7

Topic: Control and protection equipment for automation circuits.

Job Title: The study of the device and the operation of signal equipment.

Objective:

1. Study the device, principle of operation and technical parameters of alarm devices.

2. Learn to determine the parameters of alarm devices.

Acquired Skills and Skills:

1. Learn to assemble electrical circuits involving alarm devices.

General information

To ensure the normal operation of any devices, it is necessary to promptly and reliably inform the operating personnel about the status, operating modes and positions of individual mechanisms, drives, assemblies, about the progress of the technological process and the state of its parameters, about reaching the minimum and maximum allowable values ​​of the measured and controlled values ​​of the control object, about the danger of breakdowns, accidents, about reaching the specified or limit values ​​of operating parameters. To perform these functions, various devices and devices for light, sound and visual signaling are used.

Types of alarm

Depending on the purpose, the following alarm systems are distinguished: information (positions), warning, emergency.

Position signaling informs maintenance personnel about the status and position of electrical apparatus and circuits. Position signaling is performed for mechanisms that have two or more operating positions. The most common are two structures for constructing signaling circuits for the position (state) of technological mechanisms:

signaling schemes combined with control schemes;

· signaling schemes with independent power control schemes for a group of technological mechanisms of one or different purposes.

Signaling schemes combined with control schemes, as a rule, are carried out if the useful area of ​​\u200b\u200bboards and consoles allows the use of signaling equipment without limiting its size and allowing direct power supply from control circuits. The signaling of the position (state) of technological mechanisms in such circuits can be carried out by one or two light signals.

For example, the electric motor is on or off, good or bad, etc. Such an alarm is usually carried out using auxiliary contacts of magnetic starters and alarm lamps switched on through them, or alarm lamps switched on in parallel with the magnetic starter coil. It should be noted that both methods of signaling the operation of electric motors are indirect, so the possibility of receiving false signals is not excluded. So, for example, a magnetic starter can turn on, close its power and blocking contacts, and the electric motor will not start as a result of a phase failure or any other reason. If the thermal protection does not disconnect the electric motor from the network, the operator will see a signal that the motor is running, while in reality it may not work. A direct signal about the operation of the electric motor could be a signal from the speed relay (speed control device - UKS) of the rotation of the electric motor. However, this leads to a complication and increase in the cost of the circuit, therefore, in practice, indirect signaling methods are used. If we take into account that the probability of occurrence of the discrepancy described above (lack of rotation of the electric motor when the magnetic starter is turned on) is very small, then the admissibility of using indirect signaling schemes will become obvious. Signaling the positions of gates, dampers, etc. is made from limit switches and devices (devices) designed to perform the same functions. The limit switch is triggered at certain positions of gates, dampers, gate valves, etc. Alarm devices are switched on directly via limit switches or intermediate relays.

Warning signal notifies about the upcoming start-up of an automatic production line or an automated unit, ensuring the safety of work, and also informs the maintenance personnel about the deviation of the controlled values ​​from the set values. With centralized control of units, installations, production lines, etc. the operator does not see the result of his influence on the machines and judges their inclusion by light signals and devices. To prevent injuries to people in the room, an audible signal (siren, etc.) is given during the centralized start-up of the machines. To prevent cars from starting without a warning signal, special schemes are used.

Alarm informs about the shutdowns of the most important objects, or the deviation of the technological process from the specified course, that the controlled value has reached the maximum allowable value. An alarm requires immediate operator intervention; it will sound until the operator corrects the abnormal behavior.

Warning and emergency alarms, designed to alert maintenance personnel about a violation of the normal course of the process, are carried out by a steady or flashing light and are usually accompanied by an audible signal. The most common signaling schemes with a central sound signal pickup. They make it possible to receive a new sound signal before opening the contacts that caused the previous signal to appear.

Depending on the method of filing, the signaling is divided into light (signal lamps and displays), sound (sirens, beeps and calls) and visual.

When performing an alarm, as a rule, a combination of sound signals, sound and light signals, use of various signal colors, flashing, burning and extinguishing states, etc. The form of the alarm depends on where it is used. The nature of the production facility also affects the choice of one or another type of alarm (the presence of production noise, dust, the removal of machines from control panels, the size of the room, etc.) When signaling, the choice of one or another color characterizing the normal mode of operation is determined in each specific case based on the conditions of control, signaling control and features of the technological process. The normal position of the mechanisms, as a rule, is indicated by a green color, an emergency condition or a stop - red, a warning - yellow.

Light signaling carried out with the help of various signal fittings: scoreboards, banners, semaphores and luminous mnemonic circuits placed on consoles and control panels. Using signal lamps and fittings with caps of different colors, it is possible to communicate the necessary information by changing the operating mode of the lamp: the light signal can be reproduced by a steady or flashing light, as well as by the glow of lamps with incomplete incandescence.

In addition to lamps for light signaling, LEDs are widely used, which have a wide variety of designs and glow in different colors when a small electric current flows through them.

Light signaling using lamps is a simple and reliable means of notification. Signal lamps installed in special fittings are used to signal the operation of machines and units, the presence of voltage in the mains and control panel, etc. For reliable operation of lamps, they are usually switched on through additional resistances that reduce incandescence. Signal lamps are closed with glass caps (lenses) of various colors, in accordance with the color of the lens, the signal can have one or another meaning. For example, green color is normal state, yellow color is warning signal, red color is emergency state, white color is various production signals.

The combination of several light signals forms a light board, its capabilities are much wider than a signal lamp. An inscription can be applied to the glass, which is clearly visible when the display is turned on. In this way, entire commands are transmitted. Structurally, the board differs from the usual signal fittings in its external design.

Sound alarm. In some cases (especially for emergencies), light signaling is not enough to quickly alert the maintenance personnel. To do this, use the sound signaling equipment (bells, buzzers and sirens) included in the signal contacts circuit of the control circuit. Deactivation of the audible alarm is usually done manually after appropriate measures have been taken. Some schemes provide for automatic deactivation of the sound alarm after appropriate switching in the control circuits or from a special time relay.

Sound alarm devices are simple in design and reliable. They are used to draw the attention of service personnel to changes occurring in controlled systems, and to call personnel to a specific location. Sound equipment includes: loud ringers used for warning signaling about the remote start-up of flow production systems or their sections, as well as beeps, howlers and sirens for emergency signaling about stopping machines and mechanisms, about dangerous overflow of bunkers and other violations of the technological process.

As sound alarm devices, ordinary electric bells, loud bells, and signal sirens are used. To obtain weak sound signals, buzzer elements used in communication technology can be used.

The choice of the type of sound signaling equipment is made taking into account the importance of the objects, the size and nature of the premises and the conditions of service.

Visual alarm. In some cases, the signaling can be performed using special indicator blinker relays that change their state when a current of a certain value flows through their coil. Return to the initial state is carried out manually by cocking the pointer rotation mechanism or by pressing the pointer button (depending on the design of the relay).

Combined alarm. In addition to those listed, combined signaling devices are used in practice, for example, bells with a built-in signal lamp.

To ensure a high level of security at real estate, special electronic systems are used. These include burglar and fire alarms.

In order not to install two independent alarms, which would require large financial costs, an integrated OPS system was developed, what it is and how it is used will be discussed below.

OPS is a fire and burglar alarm, which are combined in one multifunctional system.

The advantage of such complexes is that they have a single software and hardware module that controls the operation of all security and fire sensors, as well as external systems and devices that maintain security at the facility.

Modern security and fire alarms can be part of:

1. automatic fire extinguishing systems;
2. smoke protection;
3. integrated security systems;
4. access control systems.

The purpose of the OPS

In accordance with the GOST 26342-84 standard, the main task that a security and fire alarm system must solve is to receive alarm signals from sensors, process them, then transmit an alarm signal to the security and fire services consoles, and also provide users with information about an attempt to enter the premises or about fire.

Purpose of means of the security and fire and disturbing alarm system:

• support of the round-the-clock control of the territory of the protected object;
• detection of fires at the earliest stages;
• accurate determination of the place of penetration to the object or the beginning of a fire;
• providing security and fire services, as well as property owners with information about a burglary attempt or the start of a fire;
• management of warning devices, autonomous fire extinguishing, smoke removal, personnel evacuation;
• automatic self-diagnosis of security and fire sensors, as well as executive systems;
• support for full alarm functionality when powered by redundant power supplies.

OPS classification

Fire and security alarm systems have their own classification, which includes three categories.

address

This security and fire alarm system is designed to monitor large and medium-sized facilities, protecting them from robbery and fire.

Such alarms allow you to determine the exact location of the start of a fire or penetration.

This feature is associated with the ability of the sensors used to transmit to the central console, in addition to the alarm signal, also data on which of the sensors and in which loop worked.

Thanks to this, it is possible to accurately determine a dangerous place, which will allow timely liquidation of a fire or neutralize intruders.

Non-targeted

This type of security and fire alarm system is designed to protect small-scale objects.

Its difference from the previous system is that it allows you to determine only the number of the loop, the sensor of which transmitted an alarm signal. To determine the exact place where the danger is detected, this type of system does not allow.

Addressable analog

Fire and security alarms of this class are among the most highly efficient and reliable systems that continuously monitor the protected object by analyzing various telemetric information: air temperature, presence of smoke, strong mechanical vibrations, sound waves, etc.

The main difference from all previous OPS is that the decision to notify a hazard at the facility is made by the central processor based on the analysis of a set of indicators obtained from different sensors and sensors installed at the facility.

This type of security and fire alarm system is a complex electronic complex, which is characterized by high accuracy in determining the places of danger and practically does not have false positives.

In addition, this type of alarm provides for the constant receipt of information from the sensors about the controlled parameter, so if a sensor breaks down, this can be instantly found out through a visual notification of the alarm control panel.

Standard set of OPS

A fire and security alarm of any of the listed types incorporates a certain set of devices that ensure its functionality.

The main ones include:

1. detectors (security and fire sensors);
2. reception and control console;
3. hazard warning devices and systems;
4. communication lines between sensors and the console, as well as between the console and sirens (can be radio channel, wired loop, GSM or GPRS);
5. backup power system (this can be a battery, a gasoline / diesel generator, thanks to which the alarm system functions continuously);
6. peripheral executive devices;
7. specialized software for signaling operation control.

The sensors that are equipped with a fire and security alarm system, depending on the technology for detecting penetration into an object or the presence of a fire, are divided into the following categories:

• ultrasonic;
• infrared (passive or active);
• magnetic contact;
• radio wave;
• vibration;
• acoustic;
• light;
• combined action.

Depending on the specific tasks for which security and fire systems are designed, they may also include other types of sensors that allow you to control the parameters of the environment.

These can be sensors that control air temperature and humidity, gas and water leakage, etc.

Their use will significantly expand the purpose of automatic fire alarms, providing them with functions that are typical for systems such as "smart home".

There are many types of sensors that are equipped with security systems.

Among those used by fire alarms, the following should be highlighted:

1. smoke - determine the presence of smoke in the room (depending on the sensor used, they can be photoelectric, ionization, differential, aspiration, optoelectronic, radioisotope);
2. temperature (thermal) - fix the temperature rise above the set threshold (they can be differential, absolute, linear thermal cable, multipoint);
3. flame sensors - determine the presence of open flames (the fire alarm system can have ultraviolet, infrared, optoelectronic and multi-range);
4. gas sensors - detect the presence of a certain concentration of gas in the air (they can be semiconductor, electrochemical, optoelectronic, thermal wave, thermometric);
5. multi-sensor sensors - this type of device can detect a fire by several parameters, the number of which is determined by the number of sensors in the sensor.

Standard functionality

Regardless of model and manufacturer, every fire and burglar alarm should provide a standard feature set that includes:

• detection of fires in the early stages;
• determination of the moment of penetration to the object;
• detection of gas or water leaks in the premises;
• determination of temperature increase above the norm, as well as the appearance of smoke;
• transmission of an alarm signal to the consoles of security and fire services;
• activation of warning and alarm systems;
• management of stationary smoke removal and fire extinguishing systems;
• management of the process of evacuation of people from the facility.

From what is presented above, we can conclude that even the basic functions that the fire alarm system has will effectively protect the object from fire and robbery.

Features of the design and installation of fire alarm systems

In order for the security and fire alarms to function effectively, it is important to correctly design it and subsequently perform the installation of all functional elements with high quality.

The main points to be considered when designing an OPS system include:

1. choice of structure and type of system used;
2. determination of the number of security and fire sensors of a certain type;
3. analysis of the need to place additional functional sensors and sensors at the facility;
4. selection of the type and characteristics of the communication line through which communication will be carried out between the central console, detectors and actuators;
5. selection of the receiving and control console, which should control the operation of the alarm and communicate with the fire and security service consoles (the console must be compatible with the consoles);
6. determination of the optimal sources of autonomous power supply, thanks to which the security and fire alarm system will function without interruption.

In the design process, it is also important to consider the possibility of expanding the alarm functionality in the future. In such a case, the alarm system can be easily upgraded by adding new sensors or warning devices without the need for significant reworking of an already functioning system.

Conclusion

A modern security and fire alarm system is exactly the security tool that will protect the facility from both “uninvited guests” and a possible fire.

Today, there are a large number of both ready-made kits and individual devices, with the help of which an optimal fire alarm system for a particular object can be built.

In order for the fire safety system being created to always function correctly and be able to help in case of trouble, you should entrust the installation of such systems to professional companies.

They will competently draw up a project, select the appropriate equipment and perform its installation and configuration. Subsequently, the client will have a multifunctional and fail-safe fire and security alarm.

Video: Fire and security alarm

Varieties (types) of security alarm systems

The main task of burglar alarm systems is to timely notify the owners of the premises or law enforcement agencies about an attempt to illegally enter the territory of the premises under protection.

This goal is achieved only if the premises are properly equipped with modern and high-tech alarm systems. These alarm systems can be autonomous, and then their main purpose is to scare off the offender and notify others about an attempted unauthorized entry into the protected area using a sound siren. But a much greater effect will be achieved if the alarm system is brought to a centralized control panel of a non-departmental security or a security company. Usually distinguish the following types of security alarms.

Autonomous alarm system

When using it, the territory of the room is equipped with special sensors, sound sirens, as well as strobe flashes. All these devices are connected to a common control panel. In case of penetration into the territory of the protected premises, one or another sensor is triggered. The signal is transmitted to the control panel, which activates warning devices (sirens and light flashes). Activation and deactivation of an autonomous alarm system is usually performed from the keypad or using a key fob.

GSM alarm system

When using this type of security alarm, special sensors and a GSM module are installed on the territory of the protected facility. The system is also managed using the control panel. If the sensor is triggered, then such a system starts transmitting alarm signals in the form of SMS or voice messages to the mobile phones of responsible persons. This type of security system is also initiated using a key fob or keypad.

Phone line alarm

As in other types of systems, the protected area is equipped with special sensors, and a communication unit and a control panel. When an alarm signal is received and the system is triggered, a special module is activated, which starts sending voice messages to the phone numbers programmed in it. Enabling and deactivating the alarm system is carried out using the keypad or a special key fob.

Alarm system with output to the security console

The room is equipped with sensors and a communication module that are connected to the control panel. When one of the sensors is triggered, the signal from the control panel will be sent to the centralized security console. Telephone lines, radio frequency channels, or GSM lines can be used as channels for communication with the security console. In order to increase reliability, it is possible to use several of the listed data transmission methods together. Arming and disarming the alarm system is carried out autonomously with confirmation of the action to the operator of the security console.

In modern conditions, more and more owners of city apartments are installing fire alarm system, and the owners of suburban real estate consider the presence of such a system an indispensable condition for normal living. Types of security alarms may differ only slightly, since the operation of such systems is organized according to the same principle. The basis of the security system is a device to which, with the help of special lines (loops) various types of sensors are connected. Each sensor type responds to a specific event. This could be broken window glass or smoke in the room.

Wired and wireless security systems

All security and fire systems are organized according to the general principle. Sensors are triggered by a specific event, this causes the control device to switch from standby mode to alarm mode. The alarm mode, in turn, is accompanied by a certain action. This may be turning on a siren or transmitting a signal about unauthorized entry into a protected area into a security structure. The device can be programmed to perform actions according to a given algorithm.

Sensors

Types of alarm systems imply the mandatory use of different types of sensors. The simplest sensors in design are magnetic contact devices, consisting of a permanent magnet and a sealed contact. These sensors block all doors and windows. The sensor is installed in such a way that when the door is closed, the magnetic field keeps the contact closed. When a door or window is opened, the magnet moves away from the contact and the circuit opens.

In some cases, a burglar alarm is allowed, made only on contact sensors, but the reliability of such a system will, of course, be very low. It is also not recommended to use only infrared passive sensors without blocking entrance doors and windows.

To block the internal volume of the room, sensors are used that respond to the thermal (infrared) radiation of a physical object. Such sensors have a certain length of the detection zone, as well as a capture angle. Any movement of a physical object in the sensor's sensitivity zone will be immediately recorded. Radio wave sensors work on a similar principle, only they record the movement of an object using the microwave location method. The burglar alarm can also include sensors that respond to the sound of breaking glass, sensors that detect attempts to break walls or dig, but they are used much less frequently. All types of security and fire alarms include special sensors that respond to exceeding a certain temperature threshold - thermal sensors and sensors that respond to smoke in the room.

wires

Installation of fire and security alarm systems is carried out using a special wire, which ensures high reliability of wire lines. Wireless security systems are currently gaining more and more popularity. This is due to the fact that the cost of such devices is available to anyone, and installation does not require the involvement of specialists and you can connect and set up such an alarm yourself.

Each sensor included in the wireless system is equipped with a tiny transmitter at a frequency of approximately 400 MHz with a communication range with the base unit up to 50 meters. A compact battery or an accumulator can be used for power.

Of course, this only applies to home systems. The professional type of security alarm, which includes hundreds of sensors, is organized according to a more complex principle. Such systems can use the S2000M control panel for 2048 zones, and the security and fire alarm itself is organized according to the analog address principle.

A modern universal alarm system, organized using various types of sensors and with connected warning devices, is quite reliable and is designed for continuous and continuous operation. You can easily install a wireless alarm yourself, but you should not refuse to consult with a specialist. This will help to avoid possible errors during self-installation and configuration.

Any burglar alarm, regardless of the device and type of alert signal, is designed to inform the user about unauthorized entry into the facility.

Detection of the presence of an undesirable person in the building is provided by the installation of sensors, and the notification system can be centralized or autonomous.

The system can transmit intrusion notifications in two ways - by sound and / or by means of light signals.

In the first case, it is necessary to use sound annunciators (sirens, bells, and so on), in the second - light (LEDs or lamps).

In modern devices, instead of lamps and bells, more reliable and durable signaling devices on semiconductors or piezoelectric emitters are used. Such devices, among other things, are characterized by smaller dimensions and the possibility of fine tuning.

Other required outline elements include:

• intrusion or presence sensors;
• reception and control panels and devices (PKP);
• event data transmission equipment.

Information about intrusion into the protected object can be transmitted remotely, to the centralized security console or the owner's mobile phone. If this possibility is not provided (or the option is not used), we are talking about an autonomous burglar alarm system.

The latter option is extremely inefficient in operation and is not recommended for use. Its arrangement is justified only in the case of permanent presence of the controlling person in close proximity to the protected object.

Transmission of an intrusion signal to an object can be carried out in two ways - wired or wireless. Wired systems transmit relevant information over a dedicated or busy telephone line, depending on the owner's capabilities and proposed installation options.

The advantage of this type of signaling is a high-quality, guaranteed stable direct and feedback connection with the monitoring console, the possibility of constant monitoring of the communication channel.

Wireless alarms use the network of any cellular operator or a dedicated radio channel. When using GSM alarms, the most important thing is to ensure continuous monitoring of the presence of communication. Otherwise, it cannot be ruled out that information about the intruder simply will not be brought to the attention of the operator of the security console or the owner of the premises in time.

You can verify the availability of communication by receiving a signal from the protected object or by sending a request from the centralized protection console and receiving the system's response. Using the second option is more expensive, since it requires the presence of a transmitter and receiver in the GSM module. In addition, it is necessary to have a bidirectional communication channel.

The connection check can only be discrete: this means that the request is sent at more or less short, but still finite, intervals of time. The shorter these intervals, the more reliable the burglar alarm.

OPERATING PRINCIPLE OF THE ALARM

Of practical interest to the owner of the protected object is the object part of the alarm system installed in the building or premises.

It is from its high-quality arrangement and functioning that the overall reliability of the system largely depends. The components of signaling equipment have been listed previously. Below will be discussed in more detail about the most commonly used - sensors.

The direct purpose of sensors or detectors is to detect unregulated penetration into a protected area. You can invade the room through a window or doorway, as well as through a gap made in the wall. Therefore, it is necessary to ensure the functioning of sensors that respond to all methods used by intruders.

Security alarm sensors (detectors) are used to detect:

• opening windows and doors;
• breaking through walls and ceilings;
• breaking glass structures;
• movement within the protected area.

In order for the information to be conveyed to the operator of the central console, it is necessary to convert the detected action into an electrical signal. For example, if the sensor responds to the sound of broken window glass, such a device is called acoustic (sound).

If an intruder breaks through a wall or tries to knock out a door, a vibration sensor will react to his actions, fixing blows to the building structure.

Relay contacts, digital signal generators and other modern technological solutions can be used as detector outputs. After the formation of the electrical signal, it is necessary to ensure its further processing. For this purpose, control panels and control panels are used. Further, the information is sent to the notification and transmission devices.

Signal transmission can be carried out both by wire and by means of GSM and radio channel devices. In most cases, wireless communication refers to the method of transmitting data over a radio channel.

VARIETIES OF SECURITY ALARM SYSTEMS

There are many principles for classifying the systems mentioned: by the presence or absence of a centralized security console, the types of sensors used, the use of wires and the number of communication lines.

Depending on the method of information transmission, security equipment can be:

• wired;
• wireless.

The most familiar version for the end user is wired loops. For a long time they simply had no alternatives and, although they are now recognized as obsolete, they have a number of undeniable advantages.

The first of them is increased reliability, subject to conscientious installation and ensuring the integrity of the cables connecting the individual elements. The second is the low cost of parts and installation work.

In general, a wired system is great for installation in a small room or a separate building. A prerequisite for the functioning of the circuit is regular monitoring of the condition of the connecting cables.

As the name implies, in wireless versions, to ensure the interconnection of individual elements, instead of wires, a radio signal is used, broadcast over a dedicated channel or via GSM communication. The advantage of such a system is the absence of the need for construction and installation work.

Disadvantages include significantly higher prices for the equipment used and attenuation of the transmitted signal over distance. In addition, if there are strong electromagnetic fields in the alarm coverage area, it is impossible to guarantee high-quality communication.

The best option for arranging a security alarm is to create an address system. The method is applicable for both wired and wireless options. The principle of operation of the address signaling is to assign a unique identification number to each sensor. Thus, the alarm control panel can determine exactly which detector the alarm signal came from.

The main advantages of the addressable device are the ability to connect all sensors with one communication line and the low cost of installation work. Equipment for such circuits, on the contrary, costs a little more than for conventional ones. In general, address systems are the best option for the protection of large and medium-sized objects.

When choosing a security alarm system, it is necessary to focus on the technical characteristics of the premises, the manufacturer and the financial capabilities of the owner of the facility. It is best to entrust the installation and maintenance of the system to trusted certified organizations of the appropriate direction.

AUTOMATIC ALARM SYSTEMS

Since signal transmission between the elements of any circuit occurs without human intervention, any signaling can theoretically be called automatic. Currently, intelligent systems with a much higher level of automation are being actively developed.

It is extremely important that the alarm has the option of self-testing (automatic control) of operability. Such a possibility can be implemented in addressable devices, and for its operation a software add-on is required over the hardware component.

In addition, programmable systems have the following capabilities that are not available in hardware-only systems:

• integration of individual circuits into a single complex;
• differentiation of access rights of each operator;
• creation of complex scenarios of equipment operation.

No matter how modern the burglar alarm is, it is impossible to completely eliminate the risk of false alarms and the inconveniences associated with it. However, due to the possibility of a comprehensive analysis of the factors affecting the sensors, this probability can currently be minimized.

This allows you to reduce the cost of response (departure to the scene) and additional maintenance of the system, as well as create the most comfortable working conditions for the operator.

Security complexes of foreign and domestic production are presented on the market. Among the latter, the Orion system developed by NVP Bolid can be called the most successful development.

This complex has a friendly, intuitive interface, a wide range of customizable functions and the ability to configure for specific purposes.

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