Laboratory Title: FIRE ALARM SYSTEM (SMOKE DETECTOR AND HEAT DETECTOR)

1.1 Objectives

The objective of the exercise is to identify the difference of each device in fire alarm system in terms of it function and operation.

1.2 Introduction

In this laboratory activities student will be able to learn on the fire alarm system used in the building.

1.3 Theoretical Background

Fire fighting systems are required to meet the needs of tackling small fires and to prevent fire from spreading in a building. All fire alarm system basically operates on the same principle. If the detector detects smoke or heat, or fire alarm were triggered by glass breaking, then the alarm sounders operate to warn others in the building that there might be a fire and need to evacuate. For the system that protects property, it is likely that additional fire alarm signals will incorporate remote equipment that would alert the

fire brigade in the central station. Fire alarm systems are wired and can be broken down into three categories, Conventional, Addressable Analog and Addressable. In Conventional Fire Alarm System, the number of points of call or a few points call and detector are wired to the Fire Alarm Control Panel in each zone, where usually a person will wire the circuit each floor or fire compartment. Fire Alarm Control Panel will have a number of lighting zones. The reason for the zone is to provide a rough location of where the fire occurred and each zone is controlled by the number of Zone Control Panel. Control Panel will be wired to a minimum of two sounder circuits that might contain bells, electronic sounders or other audible device. Each circuit will have a final line device used for monitoring purposes.

2.1 Apparatus

Fire alarm trainer will be provided in this laboratory activity

2.2 Procedures

Procedure for testing fire alarm system, smoke and heat detector:

I. Switch on the Main Switch of the Fire Alarm Training Unit.II. .Activate the test key provided at the breakglass III. Open the magnetic contact. IV. Open the cover of the motion sensor and create the

movement in front of the sensor. V. Apply heat by using hair dryer on the heat sensor. VI. Apply smoke by using smoke tester on the smoke sensor.

VII. Push the emergency/panic button. VIII. Switch off the Main Switch of the training unit.

3.1 Discussion

3.1.1 Explain the basic principle for each of the components in the fire alarm trainer

The basic principle for each component in the fire alarm trainer;I. Break Glass and Test Key: This is a manual type of fire alarm system. The component is

manually operated which mean that it is press, the alarm would go off.II. Magnetic Contact: This is also a manual type alarm system. The alarm will go off when the

contact between the magnet is cut off by sliding the magnetic contact.III. Motion Sensor: It is an automatic type of fire alarm system. To operate the device , you need to

open the cover and create movement in front of the sensor. When the motion sensor senses motion, the alarm will go off.

IV. Heat Sensor: This is also an automatic type of fire alarm system. The alarm will go off when the temperature within the heat sensor reaches a certain degree which is 58 degree Celsius (most common fixed temperature)

V. Smoke Detector: Also an automatic alarm system. In the smoke detector , there are light rays going in a straight line uninterrupted . When smoke is present, which follows brown principle enter the smoke detector, some of the light rays interrupted and converged into the light sensor which wil trigger the alarm

VI. Emergency/Panic Button: This is manual type of alarm system. This button is situated at the fire alarm control. To activate the alarm, you simply push the button.

3.1.2 Differentiate between the ionization and visible smoke detector heads

An ionization smoke detector head have a small amount of radioactive material between two electrically charged plates, which ionizes the air and causes current to flow between the plates. When smoke enters the chamber, it disrupts the flow of ions, thus reducing the flow of current and activating the alarm.

A visible smoke detector head  aim a light source into a sensing chamber at an angle away from the sensor. Smoke enters the chamber, reflecting light onto the light sensor; triggering the alarm.

3.2 Conclusion

There are mainly two types of fire alarm system which are automatic and manual . For Automatic,we have motion sensor,smoke detector and heat detector. On the other hand, for manual we have break glass, magnetic contact and emergency/panic button. We have discussed the function and operation of each component in 3.1.1

4.1 Referrences

Alias, S., Hassan, S. H. A, et al (2011). Building Services. Laboratory Manual. Universiti Teknologi MARA Pulau Pinang.

5.0 Appendices

5.1 Smoke Detector

5.2 System Control Unit