Receiving and control device (PPK): overview, purpose

Today, the need to equip an apartment building or a public building with an automatic fire alarm system is no longer in doubt. Such installations consist of a whole complex of devices and devices for various purposes, the main task of which is to detect ignition in the early stage of a fire. The core of such a system is the fire alarm control panel, abbreviated PPKP.

Main functions

By definition, PPC is a device for receiving signals from detectors, their power, notifying personnel through sound and light annunciators, transmitting notifications to the monitoring station, forming a starting pulse for control devices. Thus, the basic functions of the receiving-control device:

• Arming and disarming;
• Reception and analysis of signals from sensors;
• Control of the condition of loops;
• Power supply of current-consuming detectors;
• Light and sound notification of operational personnel;
• Transmission of plant status notifications to the central monitoring station;
• Starting devices or control circuits for engineering equipment, fire fighting, warning.

Classification

The receiving-control device is classified according to the following characteristics:

• Information capacity;
• Informative;
• A method for monitoring detectors;
• Type of communication channels.

Information capacity is characterized by the number of fire plumes that can serve the device. By this feature, the devices are divided into:

• Up to 8 loops - small capacity;
• From 9 to 64 loops - the average capacity;
• More than 64 loops - large capacity.

Informative characterizes the number of notifications issued by the device, such as "Fire", "Warning", "Fault" and others. Devices can be:

• Low information content - up to 8 notices;
• Average informativeness - from 9 to 16 notifications;
• Great informativeness - more than 16 notices.

By way of control, address and analog systems are identified. In address systems, each detector is equipped with a microprocessor that communicates its status to the controller via a digital link. In the analog system, the sensor changes its resistance depending on the state, the receiving and monitoring device captures this change.

By the types of communication channels, automatic fire alarm systems are divided into wired and radio channels.

Analog radial systems

Traditionally, receiving and monitoring devices with analog radial stubs are used. In each loop of such a device, several detectors can be installed to protect different rooms. When any detector is triggered, the resistance of the loop drops, and the PPCT generates an alarm signal. At the same time, it is impossible to determine the exact place of ignition, the state of the whole loop is fixed. Therefore, the number of detectors in the loop is limited to 15-20 pieces, and the number of rooms protected by one loop is 10 (within a single storey). The status of each loop is indicated by the color of the glow and the flashing of the LED indicator.

Such receiving and monitoring devices are issued in the form of complete modules that perform all the functions provided by the norms. The main advantage of such devices is the ease of installation, adjustment and operation. To ensure uninterrupted power supply, they are equipped with built-in redundant power sources with a battery.

As a rule, devices with radial stubs are produced by a ruler, depending on the information capacity. For example, the popular reception-control device Granit is available on 2, 3, 4, 5, 8, 12, 16, 24 loops. Such a model range makes it possible to use instruments on objects of various sizes.

Address signaling

Address systems are gradually replacing the analog, replacing them not only on large, but on medium and small objects. The main difference of such a system is the redistribution of signal processing functions. The measurement of fire factors (temperature, smoke, flame brightness), their digitization and analysis are performed in a fire detector. For this purpose, the address sensors are equipped with a microprocessor, working according to a certain algorithm. The processor not only controls the fire factor, but also analyzes its state, for example, dustiness, temperature, etc.

The receiving and monitoring device exchanges data with detectors via a digital communication line, using noise-protected protocols, which virtually eliminates the possibility of an error. In the digital line, each detector is assigned its own unique address, which allows to accurately determine the location of the device that was triggered. The presence of a microprocessor allows individual adjustment of each sensor, taking into account its dustiness, conditions in the protected room, operating mode.

The use of digital infrastructure allows the design of expandable and territorially separated structures of almost unlimited scope. For digital systems, it is important that the line of equipment from the same manufacturer contains the full range of necessary instruments. For example, the fire alarm "Bolid" includes detectors, controllers, control devices, power supplies and other equipment.

Control lines

To control the notification, engineering equipment, transmission of notices to the monitoring station, the control and monitoring devices are equipped with a set of relay contacts. As a rule, their number is from three to five in non-addressable PPKP. Increasing the control circuits is done by installing additional relay cards. In address systems, the number of outputs is increased by connecting additional modules and expanding the possibilities that fire alarms solve.

"Bolid" produces a line of signal-starting and control-starting blocks, allowing to control any engineering systems. To control the warning, blocking general ventilation, fire extinguishing, etc., output contacts must be used to ensure line monitoring for an open and short circuit. The presence of such relay outputs is separately prescribed in the passport of the device.

Fire and security alarm systems

Security devices in their functions are similar to firefighters. Often, the fire alarm system is combined with a security alarm. To control such a system, the fire alarm control and fire alarm device (PPKOP) is used. The difference of this device lies in the versatility of its trains: they allow connecting both fire detectors and security detectors .

When programming each loop is assigned a certain tactic of protection: fire smoke, security, alarm, etc. Most modern devices are equipped with just such universal loops. For example, the popular reception-control device "Signal-20" has 20 universal loops.

Power supply

Automatic fire alarm is a system that must work continuously, 365 days a year. Therefore, the reception and control fire and security device is provided with electricity in the first category of reliability. Not everywhere the power supply network is provided with this category, therefore, redundant power supplies are used to power the fire protection devices. They install batteries that support the operation of the system in the absence of main power. The battery capacity should be sufficient for autonomous operation within 24 hours in standby mode and 1 hour in alarm mode.