Fire Alarm System

AUTOMATIC FIRE ALARM SYSTEM

  • Presented by: Yam Yeow Kiat, SCDF

OBJECTIVES

  • Identify characteristics of the Automatic Fire Alarm

  • List activated fire protection systems by the alarm

  • Explain alarm panel connectivity to the control room

  • Outline the primary purpose of automatic alarms

  • Discuss common non-compliance issues

INTRODUCTION

  • Reference: Fire Code 2018, Clause 6.3

  • Reference: CP 10: 2005 - Installation & Servicing of Electrical Fire Alarm Systems

  • Concept of Automatic Fire Alarm (Auto Alarm)

TYPES OF DETECTORS

SMOKE DETECTOR

  • Types:

    • Spot Type Detectors (Ionisation & Photoelectric)

    • Beam Type (Light transmitter & receiver)

    • Air Aspirating System (Sucks in air for analysis)

  • Purpose: Ability to detect fire in its incipient stage.

IONISATION SMOKE DETECTOR

  • Contains a radioactive source that ionises air in the chamber.

  • Function: When smoke enters, current flow decreases, triggering an alarm.

  • Suitable for early detection across various smoke-producing fires.

COMPONENTS OF SMOKE DETECTOR

  • Negative Ions

  • Positive Ions

  • Anode, Cathode

  • Radioactive material

  • Battery

OPTICAL BEAM SMOKE DETECTORS

  • Components: Emitter, Receiver, Retro-reflector

  • Blockage Detection: Unobstructed light indicates no smoke; obstructed light indicates smoke presence.

HEAT DETECTORS

PNEUMATIC (RATE-OF-RISE) HEAT DETECTOR

  • Components: Flexible diaphragm and air-filled chamber

  • Functions:

    • Non-Fire Condition: Normal diaphragm position

    • Fire Condition: Diaphragm extended due to air pressure changes.

METAL STRIP HEAT DETECTOR

  • Mechanism: Expansion of metal strip causes an alarm bell to sound.

  • Non-Fire Condition: Circuit remains open.

  • Fire Condition: Circuit closes due to metal strip expansion.

FLAME DETECTOR

  • Mimics human vision using infrared and ultraviolet detection.

  • Responds to flame signatures, sending signals to alarm panels.

  • Requires direct line of sight to the fire.

VIDEO IMAGE FIRE DETECTION SYSTEM (VIFDS)

  • Requires clear line-of-sight and backup power.

  • Suitable for large spaces; avoid uneven lighting or obstructions.

  • Recordings must be available for fire investigations (30 days storage).

FALSE ALARMS

CATEGORIES

  • (a) Unwanted alarms: Inappropriate user actions

  • (b) Equipment false alarms: Malfunction of devices

  • (c) Malicious false alarms: Intentional misuse

  • (d) False alarms with good intent: Genuine belief of fire

  • Important to record categories of false alarms for investigations.

IMMEDIATE ACTIONS FOR FALSE ALARMS

  • Identify the detector causing the alarm.

  • Determine the cause and log the category of the false alarm.

  • Record any pertinent activities leading to the alarm.

FIRE ALARM SYSTEM

PRIMARY PURPOSE

  • Enhance safety of occupants with early warnings.

  • Notify SCDF via DECAMS to enable emergency response.

SYSTEM OPERATION

  • Early fire detection minimizes damage and ensures safety.

  • Sends immediate alarms to SCDF.

  • Alerts occupants and assists in organized evacuation.

  • Facilitates identification of fire zones by firefighters.

FIRE CODE COMPLIANCE

INSTALLATION REGULATIONS

  • Fire alarm systems required in specific buildings as per clause 6.3.1.

  • Alarm sounders must meet specific sound-level criteria.

  • Visual alarms are critical for areas with hearing-impaired occupants.

ALARM DEVICE CHARACTERISTICS

  • Must provide distinguishable audible signals.

  • Alarms must sound simultaneously unless authorized otherwise.

ALARM HANDLING AND RECORDS

  • Maintain records of alarms and responses for future reference.

  • Regular checks for potential false alarms.

ADDITIONAL INSTALLATION GUIDELINES

  • Manual call points must not share zones with detectors.

  • Automatic detectors needed in specified areas.

RESIDENTIAL REQUIREMENTS

  • Fire alarms are mandated for buildings with accommodations like dormitories or boarding houses.

  • Alarm bells must cover all floors in mixed-use buildings.

ATTACHMENT 1 - TABLE 6.3A: PROVISION OF FIRE ALARMS

  • Lists requirements based on purpose group and building characteristics (height, area).

DISCUSSION

  • Evaluate how differing detection principles can affect false alarm rates.

  • Analyze pros and cons of each detection method.

THANK YOU

  • Any questions or discussions on the topics covered?