Purpose:

The Addressable Automatic Fire Detection and Automated Voice Alarm System is a critical communication infrastructure in multistoried buildings during fire emergencies. It aims to detect fire and smoke, automatically alert occupants to take appropriate actions for their safety and property protection, and facilitate communication between occupants and rescue support staff.

System Overview and Components:

The system consists of main components such as smoke and heat sensors, manual call points, speakers, beacon lights, and the Control Panel. These components are connected using a 2-core cable. The Control Panel is located in the ground floor control room, while strategically positioned speakers and detection devices enable effective fire detection and communication throughout the building.

SMOKE DETECTOR ( NXPCFS112):

A photoelectric smoke detector is a type of smoke detector that utilizes photoelectric sensing technology to detect smoke within a specific area, providing early fire warnings by monitoring smoke particles in the air. Here’s a breakdown of its operation:

1. Photoelectric Sensing Principle:

• Components: The detector features a light source, typically an LED, and a light sensor (photo detector) within a sensing chamber.

• Normal Conditions: Under normal conditions, the light beam does not directly reach the photo detector.
• Smoke Presence: When smoke enters the sensing chamber, it scatters or reflects the light beam towards the photo detector.
• Alarm Trigger: The photo detector senses the increased amount of scattered or reflected light. When the detected light exceeds a certain threshold, the alarm is activated.

HEAT DETECTOR ( NXPCFS114):

A heat detector is a fire detection device that responds to changes in temperature rather than smoke. It is specifically designed to detect heat within a particular area, making it suitable for environments where traditional smoke detectors might not be effective.

How Spot-Type Heat Detectors Work:

1. Temperature Sensing:

1. • Thermal Sensing Element: Heat detectors use a thermal sensing element to monitor temperature changes in the surrounding environment.
   • Response Mechanism: They are configured to react to either a fixed temperature threshold or a rate-of-rise in temperature.

2. Fixed-Temperature Heat Detectors:

1. • Activation Point: These detectors are set to activate when the temperature reaches a pre-determined level, such as 135°F (57°C) or 190°F (88°C).
   • Trigger Mechanism: If the ambient temperature reaches or exceeds this set point, the detector triggers an alarm.

3. Rate-of-Rise Heat Detectors:

1. • Rapid Temperature Increase: These detectors are designed to respond to a rapid increase in temperature over a short period.
   • Measurement: They monitor the rate of temperature change rather than a fixed temperature level.
   • Activation: If the temperature rises too quickly (e.g., 15°F to 20°F per minute), the detector activates the alarm.

Heat detectors are commonly used in environments where smoke detectors might be prone to false alarms, such as kitchens, garages, and industrial settings.

MULTI-SENSOR ( NXPCFS115):

A multi-sensor combines both smoke and thermal sensing technologies in a single device, enhancing fire detection capabilities.

• Smoke Sensor: Detects the presence of smoke within the surveillance area. When smoke reaches the predetermined alarm threshold, it triggers an alarm signal to the fire panel for a prompt response.
• Thermal Sensor: Monitors the temperature within the same area, detecting sudden increases or abnormal temperature levels.

Note:

Multi-sensors, which incorporate both smoke and thermal sensors, should be used in locations where both smoke and temperature monitoring are necessary. This approach helps optimize the number of devices required for effective fire detection.