Fire Protection System Operation Algorithm
Our design department has completed work on drawings for the automatic fire protection system in a commercial organization building.
Automatic Fire System Operation
Comprehensive Fire Protection Functions and Algorithms Description
Automated Fire Protection System is a complex of technical means for fire prevention, detection, notification and extinguishing, ensuring people safety during fire and automatic blocking of fire safety systems, life support engineering devices and technological equipment according to set algorithms.
Automated fire protection includes the following systems:
- Automatic Fire Alarm
- Alarm and Safe Evacuation Control
- Automatic Sprinkler Fire Extinguishing combined with internal fire water supply
- Gas Fire Extinguishing
- Smoke Protection Ventilation
All listed systems are united into a single complex integrated with other installations responsible for life support, security, safety and building dispatch control.
The Automated System ensures execution of main functions and principles:
- Fire source location detection by automatic alarm means
- Automatic evacuation system control
- Automatic activation monitoring and equipment control for water and gas fire extinguishing
- General ventilation and air conditioning shutdown with fire damper closing
- Elevator recall to first floor with door opening
- Smoke protection ventilation activation
- Information transmission about fire damper status, air pressurization and smoke extraction, technical system status and cable lines, fire water supply valve positions
Visual and audio signaling:
- About fire occurrence with location identification
- About technical protection means malfunctions
- About sequential activation of smoke control dampers and fire dampers
Visual signaling:
- During short circuits or breaks in power and control circuits
- About fire audio signaling deactivation
Fire and automatic extinguishing activation signals differ in tone from malfunction signals. Capability for fire signal transmission to Emergency Services Dispatch Center is provided.
Fire System Structure and Main Technical Solutions
The system is built on certified equipment using modular principle, has distributed structure and capability to control newly installed equipment with at least 20% reserve. Automatic system consists of station, software-hardware complex, smoke sensors, input-output interface modules. All modules are powered from alarm loops. All loops have at least 25% reserve for new equipment connection.
All organization premises equipped with fire protection and space above suspended ceilings are protected by addressable analog smoke detectors according to requirements. Remote indicators are used to display status of detectors located above suspended ceilings.
Loops are executed with fire-resistant communication cable with copper conductors, double insulation, with cross-section diameter corresponding to technical specifications for detectors. Loop laying in protected premises is done in PVC conduits separately from all lighting cables and wires.
Automatic system functions:
- Recognition of dual detector activation in one loop
- False alarm protection through automatic detector reset
- Addressable analog detector connection
- Dust and smoke level measurement with graphical statistics display
- Statistics collection for safety improvement measures and maintenance organization
- Visual display of detector and device locations on floor plans, most smoke-affected detectors, daily/monthly/annual statistics
- Scenario programming for smoke protection systems, fire notification, general ventilation during fire
Along with system detectors for fire signal formation, the following are used:
- Pressure alarms on control valves
- Position sensors on valves
According to standards, shut-off devices on pipeline inputs to pumps provide visual and automatic control of their position (Closed/Open).
Fire Alarm Operation Algorithm Description
According to the project, when one automatic detector activates, the system generates "Attention" signal. When at least two automatic detectors or one manual call point activate - "Fire" signal is generated. In premises with single automatic detector, "Fire" signal is generated with time delay and detector status re-check.
When fire alarm or extinguishing system activates through interface modules, the system generates control signals for fire protection and engineering systems:
- Smoke extraction and air pressurization fan activation
- Smoke extraction and pressurization damper opening in fire zone
- Fire damper closing
- General ventilation fan shutdown
- Corresponding fire notification zone activation
- Fire signal transmission to building dispatch system
- Elevator recall to first floor with door opening
- Evacuation route door unlocking in access control system
The algorithm provides automatic smoke extraction fan start from smoke and manual detectors, flow alarms and position sensors, remote start from control station, and local start from ventilation chambers. System receives activation signals from smoke protection fans and damper positions.
In premises protected by automatic gas extinguishing, local automatic fire alarm is provided, triggering gas extinguishing. Gas extinguishing activation signal is transmitted to fire protection system. Remote gas extinguishing start from control post is also provided.
Automatic Fire Alarm Operation Algorithm
In standby mode, the panel constantly monitors for fire factors in protected premises and loop integrity with detectors.
Algorithm Type A. When one smoke detector activates on any floor:
- Displays "ATTENTION" signal with loop zone number, detector and room number
- Transmits "ATTENTION" signal to workstation
- Sends signal to shutdown supply and exhaust general ventilation fans
- Simultaneously closes fire dampers on ducts crossing fire barriers
- Provides information about complete damper closure with location address
Algorithm Type B. When two smoke detectors in one loop or manual call point activate:
- Displays "FIRE" signal with location details
- Shuts down general ventilation fans
- Closes fire dampers on barrier-crossing ducts
- Provides complete damper closure information
- Transmits "FIRE" signal to workstation
- Activates notification in corresponding zone
- Recalls elevators to first floor with door locking in open position
- Unlocks evacuation route doors in access control system
Algorithm Type C. When two smoke or manual detectors activate in smoke extraction zones:
- Displays "FIRE" signal with smoke extraction zone details
- Activates corresponding smoke extraction fans
- Simultaneously opens smoke extraction dampers in specific zone
- Closes fire dampers on barrier-crossing ducts
- Provides complete damper closure and opening information
- Activates notification in corresponding zone
- Recalls elevators to first floor
- Unlocks evacuation route doors
- Starts fire station
When control valve and flow alarm activate in sprinkler system, the panel performs functions from points B and C. During loop breaks, visual-audio malfunction signaling activates at station and control post.
Automatic Fire Extinguishing System Composition
The extinguishing system for protected premises represents stationary installations designed for rapid automatic fire extinguishing and localization before fire department arrival.
The installation consists of:
- Water sprinkler control units
- Water supply
- Pump station - complete installations based on pumps and control cabinet
- Jockey pump with hydropneumatic tank
- Automatic water supplies located on upper technical floors
- Pipeline network
- Flow switches for fire signal transmission
- Sprinkler heads
Control units are located in extinguishing pump room. On each floor, flow sensors are installed for addressable fire location determination. Control units are equipped with paired pressure alarms for activation signal transmission and ventilation shutdown/smoke protection activation.
Simultaneously with water supply, fire signal is automatically transmitted to duty personnel. Installation activation occurs automatically when sprinkler head activates. Water extinguishing activation signal transmission to automatic system is performed from pressure alarms on control unit piping and flow switches. Activation signals are received at the station.
Signals about pump group status and operation are also received at the panel. Signals about pump group status are transmitted to automation and dispatch structure. During fire or installation malfunction, visual and audio signaling activates on system panel in dispatch room and visual signaling on control cabinet panel.
Internal Fire Water Supply Purpose
Designed structures are equipped with internal fire water supply system combined with sprinkler extinguishing. It is an integral element of building fire protection.
In standby mode, internal fire water supply is under pressure ensuring constant readiness. During minor leakage or pipeline damage causing pressure drop, pressure switch sensor activates. Impulse from pressure switch is sent to control unit, activating jockey pump which maintains pressure in supply pipeline. If pressure drop is minor, upon reaching required pressure, pressure switch contacts open, jockey pump deactivates and system returns to standby mode.
During fire, when valve is opened, water is drawn from pipeline circuit causing pressure drop. During pressure drop, signal from pressure gauges on supply pipeline starts working pump. If working pump fails to reach operational mode, backup pump automatically activates from pressure gauge on supply pipeline. System operational mode control is performed by pressure switch sensors.
Extinguishing pump control:
- Remote manual - from valve position sensors and duty personnel console
- Local - from pump control cabinet buttons
Pump drive power is supplied through automatic transfer switch.
Fire Installation Power Supply
System power supply is provided according to first reliability category from two independent sources with automatic transfer switch between them, ensuring technical means operation for 24 hours in standby mode plus 3 hours operation in alarm mode during complete voltage loss. Technical means power is provided from separate panels directly fed from main distribution board.
Grounding must be performed strictly according to operation instructions. For operational safety, protective grounding from building main distribution board or group panels must be provided.
Alarm and Evacuation Control Functions
The alarm and evacuation control system is designed for timely people notification about fire, broadcasting informational, service and emergency messages, and assisting safe building evacuation. This technological platform meets following technical requirements:
- Activates from command signal generated by automatic system
- Operates during time necessary for complete people evacuation
- Audio signals provide sound level at least 75 dBA at 3 meters distance, but not exceeding 120 dBA in any protected area
- Audio signals provide sound level at least 15 dBA above permanent noise level
- Voice devices reproduce normally audible frequencies from 200 to 5000 Hz
The system has following functional features:
- Complete and maximally uniform sound coverage of all facility areas
- Maximum possible speech intelligibility
- Zone configuration with independent broadcasting capability
- High reliability degree
- Integration with automatic fire alarm
The installation includes following main elements: central device, power amplifier panels, signal sources and peripheral equipment - acoustic modules, sound loops. Main system elements are subdivided into three groups:
- System equipment - central device and power amplifier set united in common data network
- Peripheral equipment - speakers, sound paths, monitoring and fault detection devices
- Signal sources - microphone console and digital recorder with recorded messages
Gas Fire Extinguishing Engineering System
According to requirements, following premises must be protected by automatic extinguishing installations:
- Machine rooms
- Electrical rooms directly affecting computing equipment operation
- Cross-connection and apparatus rooms affecting computing equipment operation
Protected premises have no permanently open openings. Main fire load type is IT equipment and cables. Used extinguishing agent must not cause technical means failure and must not be aggressive to personnel and materials. For operational gas extinguishing agent removal after fire extinguishing, gas extraction system is used in protected premises.
Fire Protection Installation Operation Description
Electrical control of extinguishing installation provides organization fire protection through following functions:
- Automatic start
- Deactivation and automatic mode restoration
- Power supply from built-in battery during main power loss
- Extinguishing start circuit integrity monitoring, warning alarm activation
- Visual and audio signaling panel monitoring and control
- Command impulse formation for fire damper closing and air conditioning shutdown
- Command impulse formation for gas extraction system activation after installation operation
Command signals for engineering network control during fire are formed from corresponding outputs of fire protection device executive relay blocks. Extinguishing installation start with subsequent agent supply is performed:
- In automatic start mode, upon receiving fire signal from at least two smoke detectors in protected premises
- Remote start from start button on manual call point at protected premises entrance, and from control panel in facility security room