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Published byGerald O’Connor’ Modified over 9 years ago
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ADT490 TroubleShooting Device Failures
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2 Introduction ‣ Many problems are external to FAS ‣ Many are device problems
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3 Detection Circuit - Short ‣ 0 V across circuit terminals ‣ Increase in current or decrease in voltage -> Alarm 3
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4 Detection Circuit - Short ‣ Smoke Detector circuits have more current to operate the Smoke Detectors ‣ Smoke Detectors must be compatible with FACP ‣ No difference to Fire Alarm Control Panel: ‣ Short through Device -> Alarm ‣ Short between devices -> False Alarm ‣ Maximum current through current limiting resistors 4
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5 Detector Compatibility ‣ Sufficiently filtered ‣ Enough current to latch the circuit ‣ Below the foldback level ‣ circuit shut down ‣ device reset ‣ Tested to all FACP operating voltages ‣ Costly Test 5
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6 Wire to Wire Short ‣ False Alarm - determine after dvices have been eliminated 6
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7 Wire to Wire Short ‣ Supervisory latches - until panel reset 7
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8 Manual Station Operation ‣ mechanically operated electrical switch ‣ spring loaded push button or toggle ‣ second is key switch ‣ must be connected to circuit ‣ increase the current 8
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9 Manual Station - No Operation ‣ Improper screw connect - found during Tests ‣ wire twisted together under one screw ‣ comes loose over time 9
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10 Connections - Proper & Improper 10
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11 Open Identified ‣ Station tested but does not go into alarm 11
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12 Open Identified ‣ Wire insulation under screw - due to haste 12
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13 Device Not Connected ‣ Make connections later - never done ‣ Found during monthly or Annual test 13
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14 Wire Break ‣ When cut - scored to much -> wiggles and breaks 14
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15 Types of Manual Stations 15
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16 Station Problems ‣ Switch out of adjustment ‣ self-wiping switch may grime up in dirty spaces ‣ too much current through switch may damage contact - check station specifications ‣ bridge contacts to test - if alarm -> replace 16
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17 Station Problems ‣ corrosion on soldered lugs - check for dull cold solder 17
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18 Stations 18
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19 Alarm Operation ‣ First check the Stations ‣ Fire Department to find cause of alarm ‣ Reset station after advised by FD ‣ See next slide -> same voltage and current 19
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20 Any Difference? 20
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21 Manual Station Checklist (p. 15) 21
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22 Correct Connections ‣ Wire fully engaged? 22
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23 Heat Detectors 23
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24 Smoke Detectors 24
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25 Smoke Detectors - Damaged 25
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26 Fire Detector Checklist (p. 20) 26
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27 Sprinkler Flow Devices ‣ Direction? ‣ Vane or Pressure ‣ Pneumatic delay or retard up to 55 seconds ‣ Tamper connection -> should cause Trouble ‣ locating problem is easier - only one device ‣ may still require Boolean search 27
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28 Sprinkler Flow Devices 28
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29 Flow Switch Checklist (p. 22) 29
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30 Supervisory Devices (p. 24) 30
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31 Polarized Bells ‣ Contact can be carbonated - 12 to 150 mA ‣ Single stroke - on wrong circuit ‣ striker alignment? 31
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32 Signal / Notification Circuits ‣ Signal circuit terminals - Alarm or Supervisory? ‣ Bell connected in reverse ‣ Circuit voltage 2 to 24 volts supervisory ‣ Current limiting fuse or breaker 32
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33 Signal / Notification Circuits 33 Signal / Notification Circuits
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34 Other Polarized devices ‣ Horns, Strobes, & Electronic Horns ‣ Star Strobe - up to 1.25 A 34
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35 Unsupervised Aspects ‣ Placement - not interior components 35
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36 Polarized Signal Checklist (p. 28) 36
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37 Speakers 37
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38 Speaker Checklist (p. 30) 38
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39 Telephone Handsets ‣ low level signal -. 50 mV ‣ Wiring often twisted & shielded ‣ hook-switch controls the supervisory current 39
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40 Telephone Handsets 40
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41 Telephone Handsets Circuits 41
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42 Telephone Checklist (p. 32) 42
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43 General Fault Checklist (p. 33) 43
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44 Battery Faults 44
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45 Battery & Charger Checklist (p. 34) 45
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46 Power Supply Faults 46
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47 Power Supply Checklist (p. 35) 47
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48 End of Presentation
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