Automatic Fire Alarm System Design
Our design bureau has developed working documentation for an Automatic Fire Alarm System for a shopping center.
AFAS System Functions
The Automatic Fire Alarm System design is performed within the framework of major renovation of a shopping and entertainment center. The center is located in the region.
System Layout Solutions
The project involves major renovation of the shopping center. Premises to be equipped with fire alarm system include common areas, tenant spaces, service and technical rooms, and utility rooms.
Design solutions for the Automatic Fire Alarm System. The system is an engineering structure of fire protection ensuring people safety in case of fire. The main task is timely detection of fire sources at early stages and generating signals to control related engineering systems according to set algorithms.
Automatic Fire Alarm System
The system generates signals for ventilation shutdown and smoke extraction activation, controls installation control cabinets. Various types of premises in the renovated building are equipped with the system. According to requirements, the system network covers all room types.
The system in this project extends the existing shopping center installation, with main equipment located on the first floor. Connecting the designed system to the existing one ensures signal transmission throughout the facility during fire in the renovated area.
The project involves using existing equipment and expanding the structure by installing additional fire panels. Existing control equipment relocation is planned. Demolition of equipment, existing cable lines, detectors and relay blocks in renovation area is also planned, along with design of new installations.
During roof reinforcement period, demolition of existing alarm system elements in that area is required.
For normal operation during this period, the contractor must consider compensation measures.
Fire Alarm System
The system is organized using latest generation fire panels. The main part includes unified fire panel network, central server and automated workstations.
Various type fire detectors are provided for early fire factor detection, including:
- Addressable spot smoke detectors
- Addressable manual call points
Interface modules are used for valve control, elevator recall signals, transmission to related systems, monitoring related installations and building elements. Smoke detectors activate when smoke appears in premises, enabling early fire detection.
Equipment placement considers detector area duplication redundancy. Loop reserve is provided for possible tenant structure expansion and additional reserve for future equipment reconfiguration.
Detector placement follows fire safety codes. Horizontal and vertical distance from detectors to lighting fixtures must be at least 0.5m.
Spot smoke detector placement considers air flows in protected premises, with at least 1m distance from ventilation openings. If future tenant renovations block access to above-ceiling detectors, remote optical indicators must be connected.
Access to above-ceiling detectors for maintenance is through inspection hatches.
Manual call points are installed for staff fire signal transmission. Call points are placed on evacuation routes near building exits. Installation height ensures control element at 1.5m from floor level. No objects should block access to manual call points. Call points connect to upper-level loops.
Manual call points are also installed near fire hydrants and transmit fire alarm signals. Control and monitoring of related engineering installations is performed through control modules.
Implementation Solutions
Signal transmission for general ventilation shutdown during fire is performed using control modules. Single-channel monitoring modules provide input switch position monitoring.
Fire water supply and extinguishing system status monitoring is performed using single-channel and dual-channel monitoring modules.
Fire and smoke damper control is performed zone-wise using single-contact control modules. Damper position monitoring uses dual-channel monitoring modules.
Functional interaction between alarm and fire systems is ensured using dual-channel control and monitoring modules. Modules transmit activation signals and monitor system status, including backup power status and line faults.
Single-contact control modules transmit signals to disconnectors for tenant entrance area notification. This module enables night system testing.
Wall-mounted addressable visual indicators are installed in ventilation chambers as duplicate fire notification in high-noise areas.
System Integration
Automation system and fire alarm system interaction is organized using control and monitoring modules. Fire signal transmission for smoke extraction systems, valve control signals, and monitoring of control panel parameters is performed.
Elevator control during fire is performed using single-channel control modules.
Escalator control uses dual-channel control and monitoring modules. Fire curtains are installed near escalators. Curtains lower during fire via single-channel control modules. Lowering signal follows specific algorithm without delays. Curtain purpose is to prevent smoke spread to upper levels.
Access control door unlocking for free evacuation uses single-channel control modules installed near access control blocks. Modules transmit door unlocking signals zone-wise. Design considers that the system follows existing facility fire alarm algorithm. Two-level 'Fire Alarm' mode activation is implemented.
Level 1 - pre-alarm, initiated by single detector activation. Level 2 - 'Fire Alarm', initiated by at least two fire detectors in same fire zone activated by AND logic.
Level 1 event cancels when Level 2 occurs in same smoke extraction zone. Level 2 signals in different building parts activate Level 2 algorithm for each part.
If no cancel signal within 4 minutes, evacuation message transmits automatically. After danger confirmation and evacuation decision, evacuation message transmits. Evacuation cancellation is prohibited after activation.
Each tenant connects to separate fire alarm loop using fire-resistant boxes, enabling loop reorganization without losing system functionality. Lower-level loops allow tenant equipment modifications during renovations.
System Reserve
Design provides component base reserve:
- Uninterruptible power supply reserve at least 30%
- Cable product reserve at least 25%
- Tray fill reserve at least 30%
- Addressable capacity reserve at least 15%
Equipment and Cable Route Installation
Spot detectors mount to horizontal room surfaces on ceiling slabs. If ceiling mounting impossible, detectors install on walls and partitions not lower than 0.3m from ceiling. Manual call points install on evacuation routes near building exits at 1.5m height from floor level. Objects blocking access must be absent within 0.75m. Illumination at call point locations must be at least 50 lux.
Fire alarm loops use fire-resistant cable. Power cables and industrial interface cables are also used.
Fire alarm loops must be laid 0.5m from parallel power cables, crossing at 90 degrees. Closer placement is allowed with electromagnetic interference shielding. Distance reduction to 0.25m is permitted for unshielded cables near single lighting wires and control cables.
Cables lay in smooth and corrugated PVC conduits and cable trays. Wall penetrations use embedded conduits. Cable passages through walls and ceilings must be sealed with fire-resistant materials.
Cable laying follows cable support standards. Different support types are used for tray routes and open cable laying. Cable passages through walls and floors use steel pipe segments.
Horizontal and vertical cable channels have fire spread protection. Cable passages through fire-rated structures have fire resistance not lower than structure ratings.
Cable line marking tags with cable information must be installed at least every 50m, at both sides of floor and wall passages, and at equipment entries. After installation, technical means are marked with protected room names and device purposes.
All connection design work, physical connections, programming and configuration are performed during shopping center non-operating hours. Safety equipment non-functioning during operating hours is unacceptable. After installation, system technical means are marked with protected room names and device purposes.
To minimize existing platform downtime, system integration should occur only after all line elements and newly designed cable segments installation. Device downtime should be minimal, with programming and function setup during night hours. System operation must be restored before center opening.
Power Supply and Grounding
According to fire safety codes, fire automation power consumers belong to first reliability category.
Backup power sources maintain system operation for 30 hours in standby mode and 1 hour in Alarm mode.
For personnel protection against electric shock, protective grounding of metal elements must be performed according to electrical codes.
All installation work must be performed according to designed documentation and regulatory acts by licensed companies. Installation and commissioning must be performed by qualified personnel.
Function programming must follow system documentation and control matrix, fully complying with fire algorithm requirements.
Secondary Power Source Calculation
For uninterrupted power supply, additional power sources must be provided according to standards requiring at least 30 hours standby and 60 minutes alarm operation.
To meet requirements, each fire panel requires four lead-acid batteries.
Equipment Current Calculation and Justification
Total power consumption of panel and built-in modules in inactive state is approximately 0.86Ah.
- 30-hour calculation: 0.86Ah × 30h × 1.2 = 31Ah
- 1-hour alarm calculation: 1Ah × 1h × 1.2 = 1.2Ah
- Total required: 31Ah + 1.2Ah = 32.2Ah (with 20% reserve)
- Equipment comparison: 34Ah > 32.2Ah - Requirements met
Installation
Battery connection uses series pairs with parallel connection between pairs, using power cable with minimum 2.5mm² cross-section.