Fire alarm system - basic knowledge

Fire alarm systems are one of the important systems in construction projects in particular and projects in general. Fire alarm systems are directly and indirectly related to the health and lives of many people.

The fire alarm system is one of the first criteria for authorities to consider whether the project should be put into use or not. Therefore, understanding fire alarm systems is essential knowledge for everyone.

1. Concepts: Automatic fire alarm system is a system of equipment that automatically detects and notifies fire locations (according to Vietnamese standard TCVN 5738-2001). Automatic fire alarm system includes: Fire alarm center, fire detectors (bell, light, push button combination) and other peripheral devices..

2. Mission: Depending on the fire prevention scenario, building architecture and intended use; number, type of users... fire alarm system includes the following tasks:

- Automatically emit alarm signals, indicators and control signals of peripheral devices of the automatic fire alarm system to perform a specific task.

- Automatically detect fire quickly, accurately and promptly in the area the system is protecting. - Transmit fire notification signals to fire prevention agencies or other emergency response organizations.

- Automatic fire alarm systems can also turn off power, control air handling equipment, or other special operations (elevators, fire doors...).

- In particular, with an automatic fire alarm system using a smoke detector, it also has the more important task of ''warning'', that is, detecting and reporting impending fires and smoldering fires without flames. fire.

3. Nguyên lý hoạt động:

The operating process of the fire alarm system is a closed process. When there is a fire phenomenon (such as a sudden increase in temperature, the appearance of smoke or sparks), input devices (detectors, emergency switches) receive signals and transmit information to the fire. Fire alarm center incident. Here the center will process the information received, determine the location of the fire (through zones) and transmit information to output devices (auxiliary display panels, bells, whistles, lights), These devices will emit sound and light signals to help people recognize the area where the fire is occurring and take timely action.

4. Classification: Fire alarm systems are divided into 2 types:

- Conventional fire alarm system: Conventional fire alarm cabinets range in size from 1 - 60 channels. Each Zone can be 1 room or many rooms close together. Each Zone needs its own signal line, so the number of wires to the fire alarm center is large. Some fire alarm panels allow expansion of zone capacity while others do not, which limits their usefulness when a facility wants to expand.

- Addressable fire alarm system: The point capacity (address) of an addressable system is determined by the number of loops, also known as its signaling circuits (SLC - Signaling Line Circuits). Each loop can accommodate over 100 addressable devices, depending on the manufacturer, providing power, communications and monitoring of all devices connected to it. Fire alarm system - basic knowledge