Flame Detector User Manual
Contents
1. with the DIL switch will energise and the contact between terminals 7 and 8 will close If 24Vdc is applied to terminals 3 and 4 or terminal 3 is linked to terminal 1 the detector will perform a self test It does this by causing internal optical test sources to simulate the behaviour of flames and the detector will alarm Fig 12 Portable Flame Detector Test Unit Service amp Repairs Servicing of the fire protection system should be carried out by competent persons familiar with this type of system or as recommended by the local regulations in force 11 Alternatively a portable flame sensor test unit is available to generate simulated flame behaviour and test the detector a few metres in front of the detector See Fig 12 Finally provided it is safe to do so carry out a flame test using a flickering flame source such as a portable Bunsen burner See Fig 13 A still non flickering flame will not produce a response from the detector Fig 13 Portable Bunsen Burner Only the manufacturer or equivalent authorised body may carry out repairs to the flame detectors In practical terms this means that flame detector may be repaired only at the manufacturers factory Flame Detector Refer to note 3 Fig9 4 Wire Connection Diagram Two pair cable also see note 1 Control Unit Interface Supplied by others 24Vdc Normal Break supply to reset if detector set to latch2. 0 0 Medium 4s 1 0 Fast 2s 0 1 Faster response times reduce the optical interference immunity Very Fast 1s 1 1 Sensitivity See EN 54 10 Low Class 3 High Class 1 rd Table 2 Connection Terminal Descriptions Factory settings Table 3 DIL Switch Settings
3. 0 4m in order to be detected at 40metres In a rectangular room the distance from the flame detector to the fire is calculated by the formula Maximum distance V L2 W2 H2 In the example shown in fig 1 the room in which the flame detector is to be installed measures 20m x 10m x 5m the maximum distance from the detector to the flame will therefore be Maximum distance V 202 102 52 22 9m Fig 1 Calculation of distance from detector to flame Field of View The flame detector has a field of view of approximately 90 as shown in the diagram below Fig 2 Conical field of view of the flame detector Centre line of detector 0 4m flame seen at 40 0 1m flame seen at 25m Detector Fig 3 Detector Field of View Plot The flame detector should be positioned at the perimeter of the room pointing directly at the anticipated flame or at the centre of the area to be protected If the detector cannot see the whole of the area to be protected one or more additional detectors may be required The flame detector is not affected by normal light sources but should be positioned so that sunlight does not fall directly onto the viewing window Detector Window Contamination It is important to keep the detector window clean and checks should be carried out at regular intervals determine locally according to the type and degree of contamination encountered to ensure optimal performance of the flame det
4. 4 20mA systems amp relays 8mA 28mA 1 1 1 1 Fire control panels Table 4 Detector Supply amp Alarm Currents If the detector supply current falls below the normal quiescent current consumption then a fault is present This could be simply an open circuit cable fault or a fault within the detector possibly due to the detector being taken over its rated temperature Detectors can be connected in parallel increasing the overall quiescent current required The alarm current signal will remain the same with the additional quiescent current drawn from other detectors Theory of Operation The detector responds to low frequency 1 to 15 Hz flickering IR radiation emitted from flames during combustion IR flame flicker techniques enable the sensor to operate through a layer of oil dust water vapour or ice Most IR flame sensors respond to 4 3um light emitted by hydrocarbon flames By responding to 1 0 to 2 7um light emitted by every fire all flickering flames can be detected Gas fires not visible to the naked eye e g hydrogen may also be detected Signal Processing The detector views the flame at particular optical wavelengths The more differing optical wavelength signals available the better the detector is at discriminating between flames and false optical sources So although IR IR and UV IR detectors can detect similar sized flames at the same distances the UV IR detector will Flame i Optics The dual IR an
5. Cover removed Electrical Connections mcs remem meen ce cm Cc IR Optics Supply ON Green Fire Red Test Yellow UV Optics Option DIL Switch Connection Terminals IR optical flame sensors amp filters Steady if detector functioning correctly Indicates a FIRE detected Indicates detector in test mode UV optical flame sensor if fitted Select detector functions The flame detector has eight connection terminals as show in Fig 5 Removing the front cover of the flame detector accesses the connections The cable is passed through the gland holes in the base of the detector Closes if flames detected Normally closed N C when powered oe e Qoo IN IN R R 24Vdc Supply Input Test Input FLAME N O Relay RL1 Fig 5 Electrical Connection Terminals FAULT N C Relay RL2 Connection Terminal Descriptions Terminal No Mnemonic Function 1 IN Power Supply V IN is the power supply input to the flame detector and is normally 24Vdc with respect to terminal 2 The current consumption of detector can be monitored to determine the detector status Fault Normal Pre alarm Fire If the detector is in latching mode then this supply line must be broken in order to reset the detector A thermal fuse within the detector will blow and break the IN connection if the detector operating temperature is exceeded Power Suppl
6. RL2 Fault or Pre alarm Relay RL2 This volt free contact is normally closed N C if the detector has no faults and the supply voltage between terminals IN and IN is the correct value If the detector mode is changed see DIL switch settings this relay can be de energised to reduce the detector current consumption Alternatively RL2 can be set to provide a pre alarm fire signal The normal contact state can be changed state by moving the link on JP2 in the rear of the detector Maximum relay contact ratings Power 3W Current 0 25Amp Voltage 30Vdc Resistive loads only Selectable Functions DIL Switch Settings Relay RL2 Function 1 2 RL2 off No fault relay For lowest detector current consumption 0 0 RL2 off or UV pre alarm flame or electrical sparks detected 1 0 RL2 energised on IR pre alarm 0 1 RL2 detector fault relay Energised if detector powered and no faults 1 1 Detector Supply Current Detector Status see Output Mode below 3 4 Low current mode 3mA 9mA RL1 Only 8mA 14mA RL1 amp RL2 0 0 Two wire current signalling only No relays operating 4 20mA 4 20mA 1 0 Two wire current signalling 8 20mA 8 20mA and both relays operating 0 1 Two wire current signalling 8 28mA and both relays operating 1 1 Output Mode Proportional analogue supply current Non latching fire alarm signalling Step change supply current Latching fire alarm signalling a Response Time 6 7 Slowest 8s
7. Information in this guide is given in good faith but the manufacturer cannot be held responsible This document is FD User Manual 2003 Issue 1 for any omissions or errors The company reserves the right to change the specifications of products at any time and without prior notice 12 Flame Detector User Manual General Description The flame detector is designed for use where open flaming fires may be expected It responds to the light emitted from flames during combustion The detector discriminates between flames and other light sources by responding only to particular optical wavelengths and flame flicker frequencies This enables the detector to avoided false alarms due to such factors as flicking sunlight Electrical Considerations The flame detector can be connected in many different electrical configurations depending on the application The detector requires a 24Vdc 14Vmin to 30Vmax supply to operate The detector can be connected as a two wire loop powered device increasing its supply current to signal that a flame has been detected See Fig 8 The supply connections to the detector are polarity sensitive Also available are volt free contacts from two internal relays RL1 Fire and RL2 Fault or pre alarm Using the relay contacts connected in a four wire configuration the detector status can be signalled back to control equipment See Fig 9 Removing the detector front cover provides accesses the detector terminals and co
8. Zone Refer to note 2 NOTE 2 R To indicate fire to control unit or interface E g 470R NOTE 3 EOL End of line device required by some control units This is required to monitor the cable to the detectors and prevent fault indications on the control unit The circuit shown above enables the flame detectors to interface with most type of fire alarm control systems The fire relay RL1 is used to switch the required alarm load R to generate a fire alarm signal An end of line device EOL mounted in the last detector provides the system with the ability to monitor the detector fault relay RL2 and the integrity of the interconnecting cables Installation It is important that the detectors are installed in such a way that all terminals and connections are protected to at least IP20 with the detector cover fitted The earth bonding terminals are provided for Fig 10 Stainless Steel Adjustable Mount 10 convenience where continuity of a cable sheath or similar if required Adjustable mounting brackets and weather shields are available as shown below Fig 11 Stainless Steel Weather Shield In fact the flame detector will detect fires at distances of up to 40 metres but the flame size at such distances needs to be proportionally greater in order to be sure of reliable detection Thus the yellow flickering flame that can be detected at 25m provided that its size is not less than 0 1m will have to be
9. d triple IR IR photoelectric detectors responding to neighbouring IR wavelengths enable it to discriminate between flames and spurious sources of IR radiation The combination of filters and signal processing allows the sensor to be used with little risk of false alarms in difficult situations characterised by factors such as flickering sunlight give the greatest optical false signal immunity as it has the most diverse selection of optical wavelengths The detector processes the optical signal information to determine if a flame is in view This is achieved by comparing the signals with known flame characteristics stored within the detector Flame Detector Terminals Signal Input Output Processing Interface Fig 7 Block Diagram of the Detector Signal Processing If the detector has interpreted the optical signals as a fire then it produces the required output responses This will be in the form of supply current changes and the illumination of the red fire LED The fire relay will also change state if required The detector is constantly checking itself to ensure it is performing correctly If a fault occurs the detector supply current will reduce the fault relay will de energise and the green supply LED will no longer illuminate constantly Detector Interior FLAME DETECTOR SENSITIVITY TOEN 54 10 LOW CLASS 3 HIGH CLASS 1 BEZLER 6903 GCS KS SSCS Fig 4 Detector with Front
10. ector Although the IR detectors can detect flames when the window is contaminated there may be a reduction of sensitivity as shown in Table 1 Contamination steal ad of Water spray 75 Steam 75 Smoke 75 Oil film 86 Salt water film 86 Dry salt deposits 86 Table 1 IR Detector window contamination UV IR detectors are more susceptible to window contamination and must be kept clean Connection Information Control Unit Supplied by others Flame Detector Single pair cable also see note 1 24Vdc Normal Break supply to reset if detector set to latch NOTE 1 Screened cable should be used with one end of the screen connected to earth Also care should be taken not to run the detector cable next to power cables Fig 8 Basic 2 Wire Connection Diagram The simplest method of connecting the flame detector is in a 2 wire configuration as shown above With a 24Vdc supply the current i drawn by a detector detectors can be monitored to determine the detector status The DIL switches within the detector can be set to produce different current values i to suit control systems Detector Supply Current DIL Switch Setting Comment i 24Vdc Normal Alarm Quiescent Fire Current Current 1 2 3 4 3mA 9mA 0 0 0 0 Lowest power configuration RL1 only 4mA 20mA 0 0 1 0 For 4 20mA systems no relays 8mA 14mA 4 1 1 0 Lowest power configuration amp relays 8mA 20mA 4 1 0 1 For
11. nfiguration DIL switch See Fig 4 Alarm Response Modes The detector is normally configured to latch into an alarm state when a flame is detected The supply to the detector has to be broken in order to reset the detector The configuration DIL switch within the detector can be set to place the detector into a non latching mode The detector can then also produce proportional analogue current alarm signals i e 8 28mA or 4 20mA In non latching mode the detector only produces an alarm signal when a flame is in view resetting itself to normal when the flame has gone 1 Application for Flame Detectors Flame detectors are used when detection is required to be e Unaffected by convection currents draughts or wind e Tolerant of fumes vapours dust and mist e Responsive to a flame more than 25m away e Fast reacting The detector is capable of detecting the optical radiation emitted by burning material even non carbonaceous materials e g Hydrogen Numerous other potential fire sources can be detected such as Liquids e Aviation Fuels kerosene e Ethanol e Methylated Spirits e n Heptane e Paraffin e Petrol gasoline Typical applications examples are e Agriculture e Aircraft hangars e Atria e Automotive industry spray booths Solids e Coal e Cotton e Grain amp Feeds e Paper e Refuse e Wood e Coal handling plant e Engine rooms e Generator rooms e Metal fabrication e Paper manufacture Gase
12. s e Butane e Fluorine e Hydrogen e Natural Gas e Off Gas e Propane e Pharmaceutical e Power plants e Textiles e Transformer stations e Waste handling parts manufacture e Petrochemical e Woodworking Applications and Locations to Avoid e ambient temperatures above 55 C e close proximity to RF sources e exposure to severe rain and ice e large amounts of flickering reflections e large IR sources heaters burners flares e obstructions to field of view e sunlight falling directly on the detector optics e spot lighting directly on the detector optics Quantities Required and Positioning of Detectors The number of detectors required and their position depends on e the anticipated size of the flame e the distance of the flame from the detector e the angle of view of the flame detector The flame detector is designed to have a class 1 performance as defined in BS EN54 10 2002 on the high sensitivity setting That is the ability to detect an n heptane yellow fire of 0 1m or methylated spirit clear fire of 0 25m at a distance of up to 25m within 30 seconds The detector can be set to have to a lower sensitivity setting equivalent to class 3 performance Class 3 performance is defined as detecting the same size fires as for class 1 but at a distance of only 12m Functional Testing When 24Vdc power is applied to the detector the green supply on indicator LED will illuminate The fault relay RL2 if selected
13. y OV IN is the return path for the detector supply current IN is also internally connected to terminal 4 Selectable Detector Functions DIL Switch Settings DIL Switch SENSITIVITY UU hion cias 12345678 Fig 6 DIL Switch with Detector Front Cover Removed Normal factory settings shown Remote Detector Test Input V No connection to R is necessary if the detector optical and circuit test feature is not required If 24Vdc is applied to terminals 3 and 4 the detector internal optical test sources will activate to simulate a flame The detector yellow test LED will flicker to indicate an optical test is progress The detector will then alarm indicating that the test was successful Remote Detector Test Input OV No connection to R is necessary if the detector optical and circuit test feature is not required R is internally connected to terminal 2 RL1 Flame Relay RL1 This volt free contact is normally open N O and only closes when a flame has been detected If the detector is in latching mode see DIL switch settings the contact will remain closed once a flame has been detected Only when the detector supply IN is broken will the detector reset and the contact open once again The contact can be changed to a normally closed N C state by moving the link on JP1 in the rear of the detector Maximum relay contact ratings Power 3W Current 0 25Amp Voltage 30Vdc Resistive loads only
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