Simplex Basic Fire Alarm System Concepts

SSimplex Fire Alarm Concepts 1987 simplex Recorder specifications oG er infwmatian were current as of pub4iiion a Sub cl change wimout notim 91 10 87 OF CONTENTS Systems Station Circuits Signal Circuits Circuitry Detection For Signal Circuits Power Supplies Power Supplies Signal Circuits Circuits Closed Station Section Systems Systems Boxes provide you with a basic understanding of fire alarm system operation At the conclusion Analyze the operation of relay controlled alarm systems during NORMAL conditions Analyze the operation of relay controlled alarm systems during ALARM conditions Analyze the operation of relay controlled alarm systems during TROUBLE conditions of trouble conditions by noting the status of components within a relay con Objective course this course you will be able to designed Recognize general fire alarm system Procedure course begins with a short definition of fire alarm systems and some extremely simple electrical circuits As you through circuitry becomes somewhat more complex but at no time does the circuitry be so complex as to overwhelm anyone with a basic knowledge of electricity course be quizzed why you were wrong before proceeding course on your understanding of the material covered Answers are given and the text following each quiz If you make a mistake on any portion of a quiz it important that you deter Don go on to new material until you are sure that you fully you have already covered material are expected advance the course at your own speed Do not rush you completed for the final competency course and feel that you have a good understanding the entire subject ask your precisely a fire alarm system anyway a fire alarm system is an electrical system designed to operate alarm signals the event of afire no mistake about it event of a fire a fire alarm system simply an electrical system designed operate alarm signals in doesn take mu ch to operate alarm signals A power supply wired to a switch and a bell will do the job Or if we something more elaborate we could use a power supply several switches and several bells as shown in fig Figure 1 provides a means of sounding horns simultaneously closing any one of three Figure 1 circuitry Describe what would happen There were an open wire at pont X There were an open wire at point Y There were an open wire at point Z How would you know if any one of these three conditions existed 1 answer to question 1 a is Closing switch 1 will cause all of the horns to sound Closing switch 2 or 3 will not cause horns to sound answer to question 1 b is Closing switches 1 or 2 will cause horns 1 and 2 to sound Closing switch 3 will cause 3 to sound answer to question 1 c is None of the horns will sound as a result of the closing of any of the switches the answe r to question 2 is The only way you will know if any of these conditions exists is by closing the three one at a time and listening to all of the horns each time a switch is closed answer to the second question points out the need for something more elaborate a simple bell ringer system fire protection After all the purpose of a fire alarm is to operate alarm signals in the event of a fire and we just that without continuously Figure 1 we can be sure that all signals will actually work when is a fire the system order to assure that signals will operate section an initiating or station the event of a fire all modern fire alarm systems are composed of three a control or an indicating or signal section station section consists of interconnected manual or automatic switches which transfer when there a fire the or visual devices which operate when there a fire and the panel section consists of interconnected consists of circuitry which interfaces between and which continually moni the condition of the station and signal section wiring station and signal sections block diagram signal sections Examine the block diagram and the schematic Then complete Figure 2 and the schematic Figure 3 show how the panel section quiz with the station VDC Ic ALARM 2 3 Figure 3 Explain what would happen if the contact in station 2 were transferred Explain what would happen if there were an open at point X prior to closing the contact of station 2 Explain what would happen if there were an open at point Y prior to closing the contact of station 2 How would you know that an open existed either the station or signal section prior to closing the contact of 2 answer to question 1 Closing the contact of station 2 applies 24 volts of DC across the coil of relay Kl This picks transferring contacts which in turn applies 24 volts of DC across the horns causing the horns to sound answer to question 2 If the wire was open at point X prior to closing the contact of station 2 relay Kl wouldn and the horns wouldn sound answer to question 3 Relay Kl would pick contacts Kl A and Kl B would transfer but only horn 1 would SOlJnd answer to question 4 You wouldn You only know that the system was defective after closing the contact of 2 far we added a control or panel section without the signal section our fire alarm protection That because our present panel section only contains other