INFRA-RED FLAME DETECTION 123 S200+ SERIES TRIPLE IR FLAME DETECTORS USER MANUAL S200+ USER MANUAL INDEX PAGE A) INTRODUCTION 1 1. 1 Flame Detection Operation 1 3. B) Introduction 2.
General Construction 4 PRODUCT APPLICATION 5 1. C) Application 5 2. Benefits of the S200+ Series 6 8 Introduction 8 2. Electrical Characteristics 8 3. Mechanical Characteristics 13 4. Environmental 16 5. Operation 17 6. Performance Characteristics 22 7. Design of System 30 8. D) SYSTEM DESIGN INFORMATION 1. Approvals and Compliance with Standards nd Patents 31 INSTALLATION 38 1. General 38 2. Mounting a Detector 38 3. E) Detector Wiring 40 4. Initial Wiring Check 55 57 1. System Checks 57 2. F) COMMISSIONING Connecting and Commissioning the Detectors 57 64 1. G) MAINTENANCE 64 General ORDERING INFORMATION APPENDIX 1 CONNECTING S241+ AS A CURRENT SOURCE DEVICE 66 67 SECTION A 1. INTRODUCTION INTRODUCTION The S200+ range of triple IR flame detectors comprises five flame detector variants. The detectors share the same flame detection circuitry, optics and main mechanical housing.
Each variant is available as an Intrinsically Safe (i) or Flameproof (f) version except the S261+ which is available only in the Flameproof version. The five variants are: VARIANT Conventional 2-Wire Interface 4-20mA Current Loop Interface Analogue Addressable Loop Interface Relay Interface MX Digital Interface INTRINSICALLY SAFE S231i+ S241i+ S251i+ S271i+ FLAMEPROOF S231f+ S241f+ S251f+ S261f+ S271f+ The S200+ Advanced Flame Detector offers a major improvement in both flame detection capability and immunity to blackbody radiation.
The S200+ is available in intrinsically safe and flameproof models except for the S261f+ which is available only as a flameproof version. In particular, the range incorporates models for conventional detection circuits (S231i+, S231f+), models for connection to 4-20 mA current loop (S241i+, S241f+), models for connection to Thorn Security Minerva analogue addressable systems (S251i+, S251f+), a flameproof model with relay outputs (S261f+) and models for connection to Minerva MX Digital systems (S271i+, S271f+).
The output of the S241+ provides a truly analogue current output and the S251+ and S271+ provide an additional level of signalling to indicate a pre-alarm condition. The detectors have been tested by LPCB to EN 54 : Part 10 and have been classified as Class 1 flame detectors on the 50m and 25m range settings and as Class 3 on the 12m range setting. For marine applications, the detectors have been tested to Lloyd’s Register Test Specification Number 1 (2002). Environmental Category ENV1, 2, 3 and 5 and to DNV Certification Notes No. 2. 4 (April 2001). 2.
FLAME DETECTION OPERATION The S200+ detectors analyse radiant energy at three different wavelengths and as such offer the full benefits of the triple IR flame detector. The detector uses a well proven, flame detection technique. This is based on monitoring for modulated infra-red radiation in the 4. 3? m waveband corresponding to CO2 emission. It incorporates Thorn Security patented techniques for improved rejection of solar energy by using a combination of two 4. 3? m filters for Gaussian noise rejection by averaging the output signal of two separate sensor elements.
Three different alarm delays of 3s, 6s and 12s are provided in all versions of the S200+. 2. 1 BLACKBODY REJECTION The S200+ implements a new concept for eliminating nuisance alarms from modulated blackbody sources. The new design incorporates a novel optical filter(1) which enables a single electronic infra-red sensor to measure the radiated energy present in two separate wavebands placed on either side of the flame detection waveband, at 3. 8? m and 4. 8? m respectively (see Fig A-1).
The signal obtained from this ‘guard’ channel is cross-correlated with the signal from the flame detection channel to provide an accurate prediction of the non-flame energy present in the flame detection waveband. This prediction is independent of the temperature of the radiation source, allowing the S200+ to provide blackbody rejection over a wide range of source temperatures. (1) Patented (see Section C, 8. 4). 1 Fig. A-1 shows the amount of energy given by a ‘hot’ object (blackbody) as viewed in the electromagnetic spectrum. This curve has a peak which moves further to the left with higher temperature objects.
The amount of energy seen between 3. 8? m and 4. 8? m can be approximated to a linear function. Thus, a measurement of the energy at these two wavelengths provides information to calculate with sufficient accuracy the level of blackbody radiation at the intermediate flame detection wavelength of 4. 3? m. The energy due to the emission from hot carbon dioxide given by a flame is superimposed on that from any blackbody in the detector field of view without adding any significant emissions at 3. 8? m or 4. 8? m, thus enabling proper segregation between non-flame signals and flame signals.
Because a large fire will possibly produce a large amount of black smoke which will behave like a blackbody and may weaken the carbon dioxide peak, signals greater than a pre-determined upper limit will be classed as a fire. The use of an optical processing technique, as opposed to the use of two separate electronic sensors for the guard channel, improves the overall reliability of the detector by reducing the number of components and eliminating the need for complex calibration procedures during manufacture. TEMPERATURE MOVEMENT FLAME ENERGY HOT BLACKBODY
COLD BLACKBODY 3. 8? m 4. 3? m 4. 8? m WAVELENGTH Fig. A-1 Radiation from Objects 2. 2 DETECTION RANGE The S200+ range can detect on axis a fully developed 0. 1m2 n-heptane or petrol pan fire at up to 50m and the same fire up to 25m on the 25m setting. A 12m setting is also available. 2 2. 3 DETECTION OF FLAME IN THE PRESENCE OF BLACKBODY RADIATION The ability of the detector to determine accurately the amount of non-flame radiation received at any one time by the flame detection channel allows a variable alarm threshold to be determined (see Fig. A-2).
This threshold is positioned so as to minimise the possibility of a false alarm due to the presence of modulated blackbody sources of different temperature and intensity. FLAME ENERGY ALARM THRESHOLD FLAME SIGNALS BLACKBODY SIGNALS CROSS-CORRELATED ENERGY Fig. A-2 2. 4 Signal Processing DETECTOR CONDITION SIGNALLING The S200+ incorporates two different colour light emitting diodes, red for Alarm and yellow for Fault. By using different flashing rates for the yellow (Fault) LED, separate indication of detector (electronic) fault and ‘dirty’ window (optical integrity monitoring) is provided.
The yellow LED is not fitted to the S251+ and S271+ detectors. The S241+ provides an analogue output current, in the range 4-20mA, proportional to the flame detection signal. The S251+ provides two pre-set current values to signal alarm and pre-alarm conditions. Pre-set currents, in the range 0-4mA, are used to separately signal detector (electronic) fault and ‘dirty’ window for both detector types. The S271+ shows the same signalling conditions as the S251+ but instead of the units being in mA, they are signalled digitally using the MX protocol. 3 3. GENERAL CONSTRUCTION Fig. A-3 shows a general view of a complete detector.
Fig. A-3 S200+ Detector – General View The detector is of robust construction to allow its use in harsh environments. The detector comprises a two-part stainless steel enclosure. The front section of the enclosure contains the encapsulated electro-optical assembly which is connected to the terminal board on the rear section by a small cableform. A sapphire window is fitted in the front of the housing. The window allows infra-red radiation to fall on the sensors, the LED alarm and fault indicators are visible through the window. The front section of the enclosure is attached to the rear section by four captive screws.
A seal provided between the front and rear sections ensures protection to IP66 and IP67. Two 20mm cable entries are provided at the bottom. All electrical connections are made to three 4-way terminal blocks (four 4-way terminal blocks for the S261f+). The detector may be fitted directly to a suitable surface or an optional adjustable mounting bracket may be used. A stainless steel guard is fitted to the ‘flameproof’ versions to protect the integrity of the window (shown in Fig. A-3). Until the end of 2004, the detectors had two cable entries at the bottom and one at the top.
The detector design has been changed to remove the top cable entry due to problems with water ingress where the top cable entry has not been sealed properly during installation. 4 SECTION B – PRODUCT APPLICATION 1. APPLICATION 1. 1 GENERAL The detectors are intended for the protection of high-risk areas in which accidental fires are likely to result in flaming combustion with the production of carbon dioxide. Typical materials in this type of risk are: a) Flammable liquids, including petroleum products, alcohol, and glycol etc. b) Flammable gases including methane. c) Paper, wood and packing materials. ) Coal. e) Plastics. These substances ignite readily and burn rapidly, producing flame, often accompanied by large volumes of dark smoke. Note: The detectors are not designed to respond to flames emanating from fuels which do not contain carbon eg, hydrogen, ammonia, metals, and should not be used for such risks without satisfactory fire testing. The S200+ series, by virtue of their construction and rejection of spurious radiation, are suitable for use both indoors or outdoors in a wide range of applications. Note: 1. 2 The detectors must be mounted to a rigid support which will not move in windy conditions.
This is to avoid false alarms due to detector movement modulating radiation from hot bodies at the edge of the field of view. Avoid mounting detectors where they are subject to high levels of vibration. USE IN HAZARDOUS ATMOSPHERES The S200i+ series detectors are ATEX/IECEx certified intrinsically safe, and are classified E Ex/ Ex ia IIC T5 or T4 (-40°C ? Ta ? +80°C). In an intrinsically safe system the detectors are suitable for use in hazardous zones 0, 1 and 2 where group IIC gases and vapours are present in explosive concentrations. See Section 8. 1 for full details. The S200f+ series detectors are ATEX certified ‘flameproof’.
They are classified E Ex d IIC T6 or T5 (-20°C ? Ta ? +80°C) and are suitable for use in hazardous areas zones 1 and 2. The S200f+ detectors are also IECEx certified flameproof. They are classified Ex d IIC T6 or T5 (-20? C ? Ta ? +60? C) and are certified for use in hazardous areas zone 1 and zone 2. See Section 8. 2. 5 1. 3 USE IN NON-HAZARDOUS AREAS In non hazardous ares it is recommended the following detectors are fitted: S231i+, S241i+ and S251i+ without a barrier. These detectors are electrically the same as the f+ versions. They are less expensive and have a wider field of view as they do not require the window guard.
S261f+ (has no intrinsically safe version available). S271f+ Do not fit the S271i+ as for this detector the MX communications is optimised for use with an IS barrier. Its performance without a barrier is not characterised. Note: 1. 4 The S271i+ will not communicate without the EXI800 and barrier fitted. FEATURES • • • • • • • • • • • • • • • • 2. A self-test facility is incorporated to test a number of characteristics, including the cleanliness of the window. The self-test may be initiated remotely. Switch selectable range settings. Switch selectable time to alarm settings.
Operational range up to 50m, fuel dependent. Remote control of range. S271+ has fast detection using MX interrupt facility. Remote control of delay, range and remote test on S271+. Completely solar blind. Very low quiescent power consumption. High sensitivity to hydrocarbon fire in oily environments. Rugged stainless steel 316 housing and mounting bracket. Flexible mounting and angular adjustment. Ease of installation. Connection for remote LED. Selectable latching/non-latching alarm output (not S251+/S271+). Selectable latching/non-latching fault output (not S251+/S271+). BENEFITS OF THE S200+ SERIES
Infra-red flame detectors offer certain benefits over detectors working in the visible or ultra-violet regions of the spectrum. For example they are: • • 6 Highly sensitive to flame thus increasing probability of early detection of hydrocarbon fires. Not greatly affected by window contamination by dirt and oil deposits thus decreasing maintenance frequency leading to operating cost reduction. • • Able to see flames through smoke, and able to see flames through high densities of solvent vapours thus increasing the probability of early detection of hydrocarbon fires over other (ultra-violet) detectors in the same conditions.
Several detectors on a single 2-wire conventional or analog addressable circuit. The S200+ series have all the above benefits and additionally are: • • • • Completely “solar-blind” in normal conditions, thus, eliminating false alarms due to direct or indirect sunlight. Insensitive to electric arcs thus eliminating false alarms from welding operations. Insensitive to artificial light sources. See Section C (6. 4) for more details on false alarm performance. Sealed to IP66 and IP67 (when suitable cable glands and sealant are used) ensuring long term reliability in harsh environments. 7
SECTION C – SYSTEM DESIGN INFORMATION 1. INTRODUCTION The electrical, mechanical, environmental characteristics and the performance of the S200+ series flame detectors, must be taken into account when designing a system which uses these detectors. This information is given below, together with guidance on detector siting. 2. ELECTRICAL CHARACTERISTICS 2. 1 S231i+/S231f+ The S231i+/231f+ detectors are two-wire devices, designed to operate on any typical conventional fire detection control equipment providing a regulated 20V dc current monitoring loop, including controllers manufactured by Thorn Security.
Compatibility should be assessed using the technical data below and it is recommended that evaluation tests are carried out prior to siting and installation. The quiescent current drain is very small and the alarm condition is signalled by a large increase in current demand. Resetting is achieved by removing the supply voltage for a period greater than 0. 5 seconds. 2. 1. 1 COMPATIBILITY WITH OTHER THORN SECURITY CONVENTIONAL DETECTORS The connection of Thorn Security’s plug-in conventional detectors, ie M300 and M600 ranges, in the same circuit as S231+ flame detectors is not generally recommended.
S231+ flame detectors may be connected in the same circuit as S131/S161 type detectors. The number of S231+ detectors per zone should be assessed taking account of good engineering principles, controller characteristics and cable parameters. As a guide, most controllers will permit 4 S231+ units per zone. We do no recommend exceeding 6 x s231+ units per zone. Note: 1) S161 flame detectors may be connected in flameproof circuits and can, therefore, be connected with S231f+ flame detectors. 2) If detectors are mixed, then an S231+ detector must be the last detector n the zone or a fault condition on an S231+ detector will not be signalled to the controller. 2. 1. 2 TECHNICAL DATA Supply Voltage: Quiescent Current: Alarm Current: Alarm Output Mode: Reset Time/Voltage: 8 15V to 28V. (Voltage at the detector when not in alarm). 350? A (typical). 33mA (typical) at 24V source, supplied via 330 ohms. 38mA (typical) with remote LED fitted. 18mA (typical) with MTL 5061 barrier fitted. See Fig. C-1. Operation must be restricted to the safe area shown by use of external resistance if necessary. Supply must be reduced to less than 2V for greater than 0. 5 seconds. Stabilisation time after eset/ power up: Equivalent Inductance: Equivalent Capacitance: 60 seconds (typical) to 90 seconds (maximum). 0mH. 1. 5nF. Note: 1) The maximum number of detectors that may be connected to a zone circuit is 6 (see 2. 1. 1). 2) The alarm currents shown above include current through a 4k7 end-of-line resistor. 3) In general, it is not possible to use a remote indicator on detectors which are supplied via a shunt barrier safety diode or galvanic isolator. 4) Where a remote LED is used, a 33 ohm resistor should be fitted in series with it to limit the current through the LED to approximately 30mA. 80
REMOTE LED FITTED WITH SERIES 33OHM RESISTOR TOTAL CURRENT IN ALARM (mA) 70 60 50 40 SAFE OPERATING AREA 30 NO REMOTE LED 20 10 0 2 4 6 8 10 12 14 16 18 20 22 24 VOLTAGE AT DETECTOR (V) NOTE: 4k7 END-OF-LINE RESISTOR FITTED Fig. C-1 2. 2 Load Characteristics in Alarm S241i+/S241f+ The S241i+/S241f+ detectors provide a 4-20mA current sink output, suitable for standard programmable logic controllers. 2. 2. 1 TECHNICAL DATA Supply Voltage: 15V to 28V (Voltage at the detector). Quiescent Current: 350? A (typical), excluding signalling current. 9 Supply Current in Alarm: 12mA (typical), at 24V supply. 0mA (typical), with remote LED fitted. 10mA (typical), with 600 ohm barrier. 12mA (typical), with 600 ohm barrier + remote LED. Alarm Output Mode: 4-20mA CURRENT SINK. (See Appendix 1 for S241+ wired as a current source output). Signalling Currents: DISCRETE SIGNALLING (OLD SYSTEM) CONDITION AFD CURRENT TYP. (mA) Fault Normal Alarm 1. 5 4. 5 17. 0 Table 1: S241+ Discrete Signalling (Old System) CONTINUOUSLY VARIABLE SIGNALLING (NEW SYSTEM) CONDITION AFD CURRENT TYP. (mA) Non Window Fault Window Fault Normal Flame Sensing 0. 0 2. 0 4. 0 5. 7 to 17. 0* Table 2: S241+ Continuously Variable Signalling (New System) * See Para 5. for Sensitivity (Range) Selection Note: The signalling mode is selected by means of a DIL switch, see section E 2. 1. In both discrete and continuously variable signalling the alarm LED will come on when a 4-20mA output exceeds 17. 0mA. Reset Time/Voltage: Supply must be reduced to less than 2V for greater than 0. 5 seconds. Stabilisation Time after reset /power up: 60 seconds (typical) to 90 seconds (maximum). Equivalent Inductance: 0mH. Equivalent Capacitance: 1. 5nF. Note: An external 33 ohm resistor should be fitted in series with a remote LED. S241+ is designed with a 4-20mA current sink output.
However, it can be wired as a current source device with limitations. See Appendix 1 for details. 10 2. 3 S251i+/S251f+ The S251i+/251f+ detectors are analogue addressable devices which are designed to operate with the Minerva range of analogue addressable fire control equipment currently manufactured by Thorn Security Limited. 2. 3. 1 TECHNICAL DATA The maximum number of detectors that may be connected to a Minerva system loop is 50. The maximum number of detectors that may be connected to each barrier in a Hazardous Area circuit is 10. Average current consumption: 350? A Stabilisation Time after eset /power up: 60 seconds (typical) to 90 seconds (maximum). S251+ analogue addressable signalling currents: DISCRETE SIGNALLING (OLD SYSTEM) CONDITION AFD CURRENT TYP. (mA) MINERVA MEASUREMENT (mA) MINERVA LIMITS (mA) Fault Normal Alarm 0. 75 2. 25 9. 0 1. 5 4. 5 18. 0 0 to 3. 0 3. 0 to 10. 4 16. 2 minimum Table 3: S251+ Discrete Signalling (Old System) ENHANCED SIGNALLING MODE CONDITION AFD CURRENT TYP. (mA) MINERVA MEASUREMENT (mA) MINERVA LIMITS (mA) Non Window Fault Window Fault Normal Pre-Alarm Alarm 0 1. 5 3. 0 7. 0 9. 0 0 3. 0 6. 0 14. 0 18. 0 0 to 2. 0 2. 0 to 4. 0 4. 0 to 12. 12. 0 to 16. 0 16. 0 minimum Table 4: S251+ Enhanced Signalling (New System) Note: 1) The signalling mode is selected by means of a DIL switch, see Section E 2. 1, Table 3. 2) ‘Remote Range’ and ‘Self Test’ selection is not available for the S251i+ when used with a shunt diode safety barrier. CAUTION: IF USING AN S251+ WORKING IN THE ENHANCED SIGNALLING MODE TO REPLACE AN S251, THE S251+ MUST BE CONFIGURED IN ‘CONSYS’ VERSION 12. 0 OR LATER. 11 2. 4 S261f+ The S261+ is only provided in a ‘flameproof’ version. The S261f+ provides a relay interface for alarm and fault conditions. 2. 4. 1
TECHNICAL DATA Supply Voltage: Fault relay: Alarm relay: Quiescent Current: Alarm Current: Fault Current: Reset Time/Voltage: Stabilisation Time after reset /power up: 15V to 28V. (Voltage at the detector). Normally closed, opens under fault conditions. Normally open, closes under alarm conditions. 11mA. (typical) at 28V supply. 30mA. (typical) at 28V supply. 37mA. (typical) at 28V supply with remote LED fitted. 350? A. (typical). Supply must be reduced to less than 2V for greater than 0. 5 seconds. 60 seconds (typical) to 90 seconds (maximum). Note: 1) The relay contacts are rated 2A at 28V dc. ) An external 33 ohm resistor should be fitted in series with the remote LED. 2. 5 S271i+/S271f+ The S271+ is designed to operate with the Minerva MX range of digital addressable fire control equipment currently manufactured by Thorn Security Limited. 2. 5. 1 TECHNICAL DATA For the Maximum number of S271i+ detectors and maximum cable length connected to the MX Intrinsically Safe loop, refer to document 17A-02-ISLOOP MX Intrinsically Safe System – Loop Loading Calculation. Stabilisation Time after reset /power up: 60 seconds (typical) to 90 seconds (maximum). The average current consumption is 500?
A. The S271+ digital signalling: CONDITION Non-Window Fault Window Fault Pre-Alarm Alarm Normal DELTA OUTPUT (Bits) ?10 ?51 and ? 11 ?153 ?190 ?68 Table 5: 12 3. MECHANICAL CHARACTERISTICS 3. 6 TECHNICAL DATA Dimensions (see Fig. C-2) Height: 167mm Width: 167mm Depth: 89. 5mm max (maximum depth with flameproof guard fitted 94mm) Weight: 3. 8kg Mounting Bracket Weight: 1. 1kg Materials Enclosure: Stainless steel 316L, ANC4BFCLC to BS3146 Part 2 Window: Sapphire Mounting Bracket: Stainless steel to BS1449 Part 2 316 S16 Screws etc. exposed to the elements: Bright stainless steel 316 Electronic Module:
Encapsulated. Electrical Access: Standard M20 gland holes (two) 13 3 X FLAMEPROOF GUARD MOUNTING POSTS 4 x M8 SURFACE MOUNTING HOLES OPTICAL MONITORING REFLECTOR SAPPHIRE WINDOW 167 100 149. 3 167 76. 5 TAG LABEL 52. 5 2 X 20mm GLAND HOLES NOTE: MAXIMUM HEIGHT WITH FLAMEPROOF GUARD FITTED (94mm) Fig. C-2 S200+ Series – Overall Dimensions 14 89. 5 max ‘SEE NOTE’ 0 50 ADJUSTMENT 68. 5 RAD 4 x M8 SURFACE MOUNTING HOLES 100 22 0 149. 3 SURFACE MOUNTING DIMENSIONS 45 0 200mm CLEARANCE REQUIRED FOR FULL ADJUSTMENT Fig. C-3 Adjustable Mounting Bracket and Surface Mounting Dimensions 15 4. 4. 1 ENVIRONMENTAL GENERAL
The design and construction of the S200+ series detectors are such that they may be used over a wide range of environmental conditions. Relevant limits are given in Para 4. 2. 4. 2 4. 2. 1 TECHNICAL DATA TEMPERATURE, HUMIDITY, PROTECTION AND PRESSURE Operating temperature range For non hazardous installations: For hazardous installations using flameproof S200f+ detectors in ATEX certified applications: For hazardous installations using flameproof S200f+ detectors in IECEx applications: For hazardous installations using intrinsically safe S200i+ detectors in ATEX or IECEx applications: Storage temperature range:
Relative humidity: Enclosure protection: Normal operating atmospheric pressure: Heat radiation from sun: -40°C to +80°C (110°C for short durations) -20°C to 80°C -20°C to 60°C -40°C to 80°C -40°C to +80°C Up to 95% RH (non-condensing) Tested to IP66 and IP67* 910mbar to 1055mbar 0 to 1000Wm2 typical * Cable gland entries must be suitably sealed to achieve the required IP rating (see 3. 4 Section D). 4. 2. 2 VIBRATION AND SHOCK The S200+ series detectors are designed and tested for vibration and shock to EN54-10 (the Standard for flame detection components of automatic fire detection systems).
For marine applications, the detectors have been tested to Lloyd’s Register Test Specification Number 1 (1996) Vibration Test 1 and to DNV Certification Notes No2. 4 (May 1995) Class A. 4. 2. 3 ELECTROMAGNETIC INTERFERENCE The detector is insensitive to radio frequency interference. It has been designed and tested to the requirements of EN54-10 (the Standard for flame detection components of automatic fire detection systems) and BS EN 61000-6-3 Generic Emissions Residential Commercial and Light Industry and EN 50130-4, the generic standard for electromagnetic immunity within the European Union.
The detectors have been tested to the product family standard for fire alarm systems, EN50130-4. Tests have proved the operation in field strengths of 10V/m at frequencies from 150kHz to 2000MHz with amplitude and pulse modulation, when installed in accordance with this manual. For Marine applications the detectors, have been tested to Lloyd’s Register Test Specification Number 1 (1996) E. M. I. Immunity for Electronic products and to DNV Certification Notes No. 2. 4 (May 1995) Electromagnetic Compatibility Tests. To comply with the above standards, ferrite tubes must be fitted to the detector base as shown in Fig. D3, Page 40. 16 4. 2. 4
IONISING RADIATION The S200+ series, like other infra-red detectors, is insensitive to X-rays and gamma radiation as used in non-destructive testing. The detector will operate normally and will not false alarm when exposed to this type of radiation although long term exposure to high radiation levels may lead to permanent damage. 4. 2. 5 CORROSION The detector is able to withstand the effects of corrosion conditioning with sulphur dioxide (SO2) concentration as specified in EN54-10. For Marine applications the detectors have been tested to Lloyd’s Register Test Specification Number 1 (1996) Salt Mist test and to DNV Certification Notes No. . 4 (May 1995) Salt Mist Test. 5. OPERATION 5. 1 ALARM INDICATION A red LED is visible through the front window which gives the same indication for the S231+, S241+ and S261+ variants. Illumination indicates an alarm. The S251+ (analogue addressable variant) and the S271+ (digital addressable variant) indicate in the same manner as the other variants, but the LED is driven by the controller. In normal conditions the LED is pulsed at two second intervals for the S251+ and 5 seconds for the S271+. Continuous illumination indicates an alarm under control of the Minerva controller. 5. 2 ALARM SIGNALLING
The detectors signal an alarm condition as follows: • • • • • S231+ – Increase in current drawn from supply, see Fig. C-1. S241+ – Current drawn on the loop will be between 5. 7-17. 0mA. (A single value between 16. 0-19. 0mA is drawn for the S241 compatible mode). S251+ – Returned current will be between 8. 3 and 9. 7mA. A pre-alarm function is also available which returns a current value between 6. 5 and 7. 5mA. The latter is not available for the S251 compatible mode. S261+ – Alarm relay will close. S271+ – Returned values will be ? 190 bits. A Pre-alarm function is also available which returns values of ? 153 bits.
The S231+, S241+ and S261+ may be set as alarm latching or non-latching. When the S241+ is operated in the Continuously Variable Signalling mode, the alarm latching function is inoperative. The S251+/S271+ have only the non-latching mode. In the non-latching mode, if the alarm source is removed for greater than 5 seconds, then the detector will stop indicating an alarm. In the latching mode the controller must be reset to remove the alarm condition. Note: The use of an S231i+ in a non-latching mode is generally possible when the detector is connected after a shunt diode safety barrier but evaluation tests are recommended. 7 5. 3 FAULT INDICATION For the S231+, S241+ and S261+ variants the yellow LED will flash indicating a fault. Different flashing rates are used to indicate different faults, as follows: • • Window obscuration: 0. 5Hz Detector fault: 2. 0Hz The S251+/S271+ will not provide a local indication for a fault, instead the fault indication will be displayed on the controller. 5. 4 FAULT SIGNALLING The detectors signal a fault condition as follows: S231+ – Open circuit fault band ie, the EOL resistor is made open circuit.
The faulty detector puts 4 pulses of total width 45ms and level 55mA on the line which is detected by the S231+ connected at the end of the zone. This detector open circuits the EOL resistor. Note: The end detector in the zone must be an S231+ with the EOL fitted as it is this device which will signal a fault, the faulty detector will indicate with a flashing yellow LED. • • • • S241+ – Current drawn on the loop will be as follows: • 0. 0 to 0. 5mA for a detector fault • 1. 8 to 2. 2mA for a window fault • 1. 3 to 1. 7mA for any fault in the S241 compatible mode S251+ – Analogue returned current will be as follows: • 0. 0 to 0. mA for a detector fault • 1. 3 to 1. 7mA for a window fault • 0. 65 to 0. 85mA for any fault in the S251 compatible mode S261+ – Fault relay will open S271+ – Digital returned values will be as follows: • between ? 51 and ? 11 bits for a window fault • ? 10 for a non-window fault The S231+/S241+/S261+ detectors may be selected as fault latching or non-latching. In the nonlatching mode, the fault condition will be cancelled up to 80 seconds after the fault has been removed. The S251+/S271+ have only the non-latching mode. 18 5. 5 SENSITIVITY (RANGE) SELECTION The range is switch selectable on a 6-way DIL (4-way S271+) switch (S1, Fig.
C-4) on the backbox terminal PCB. The following nominal ranges are available: • • • • Extended range. (50 metres) Normal range. (25 metres) Reduced range (12. 5 metres) 6m (S251f+ and S271f+ only) These ranges are for an n-heptane fire in a 0. 1m2 pan located on the main axis of the detector field of view. With the S241+ set to Continuously Variable Signalling mode (see Section E 2. 1), the nominal ranges above correspond to an alarm threshold set to 17mA. Laboratory tests indicate that setting the alarm thresholds at 9 and 15mA (as opposed to 17mA) will increase the range a fire is detected at by approximately 20 and 10% respectively.
For the S251+/S271+, the detection distance for the PRE-ALARM function is approximately 18% higher than the ALARM distance. Range can also be selected in MX CONSYS and will take effect if all switches are in the OFF position from the controller for the S271+. There is provision for halving the range value selected by the switches. If the terminal connector ‘Range’ is connected to 0V then the detection range is reduced to half that of the switch setting. This may be done by taking cables to a remote contact the other side of which is connected to the same 0V as the reference for ‘Line In’ supply. . 6 DELAY TO ALARM The minimum delay to alarm is 3 seconds from a fire being present in the field of view that is large enough to be detected. This delay is also switch selectable using 6-way (4-way S271+) DIL switch (S1, Fig. C-4), the following additional values are available: • • Note: 6 seconds. 12 seconds. The minimum delay to alarm is 3 seconds. However, with this setting, the detector requires that the alarm threshold level has been exceeded throughout for a minimum of 3 seconds in any given 5 second window. Therefore, for fires where the intensity varies, the time to alarm may be longer.
Similarly, for the 6 second setting, the alarm threshold level must be maintained for a minimum of 6 seconds in any 8 second window and for the 12 second setting, the alarm threshold level must be maintained for a minimum of 12 seconds in any 14 second window. When the S241+ is operated in Continuously Variable Signalling mode, the delay to alarm switches on S1 are inoperative. This means that in windy conditions where the fire signal varies over time, the detection range will be reduced on the longer time to alarm settings.
The signal is smoothed to reduce jitter and this results in a settling time of between 3s and 5s. Further delay could be added by the controller if required. 19 In the case of the S251+, there is additional delay to alarm introduced by the confirmation procedure of the Minerva control panel. This extra delay is between 4 and 6 seconds. For the S251+/S271f+ PRE-ALARM function, the delay to alarm settings on switch S1 are inoperative, the only delay is that introduced by the Minerva/MX panel. For the S271+, the delay may be set from MX CONSYS via the controller if all the switches are in the OFF position.
SWITCH S1 (S271+ ONLY) SWITCH S2 (S251+ ONLY) SWITCH S1 SWITCH S2 (S271+ ONLY) ON S1 ON S1 ON S2 ON S2 1 4 1 6 1 7 1 8 INTERFACE PCB CONNECTOR BLOCKS RELAYS AND CONNECTOR BLOCK (S261+ ONLY) Fig. C-4 Switch Location 5. 7 SELF-TEST The detector normally carries out a complete self-test every 20 minutes. The self-test exercises the pyro-electric sensors, electronics and monitors the window for cleanliness. If the window cleanliness test fails on 20 successive occasions (6 hours 40 minutes), a fault condition is generated and the fault LED, where fitted, flashes at the rate of 0. 5Hz.
In this condition, the window self-test only is automatically repeated every minute until the window clears and window self-test passes. If the window test continuously fails then the complete self-test will still be repeated every 20 minutes. Other self-test failures will be indicated on the first test after they have occurred. For the complete ‘self-tests’ to be run automatically, the ‘self-test’ connection on the terminal board must be left open circuit when the unit is powered up. In this mode, additional self-tests may be initiated remotely by connecting 0V to the ‘self-test’ terminal, refer to the wiring diagrams in Section D. 0 The detector may be powered up in such a condition that the window ‘self-test’ can only be initiated remotely on demand (the automatic window ‘self-test’ is disabled). In order for this to be achieved the detector must be powered up with the ‘self-test’ terminal connected to 0V (terminals 3 or 5). To initiate the test for the first time after power up, the connection to the ‘self-test’ terminal must be opened for at least 5 seconds and then closed again. This ‘self-test’ function (which takes 10 seconds) will commence within 2 seconds of the closing and the result of the test indicated for as long as the connection remains closed.
If the test passes, an alarm condition will be indicated and if it fails a fault condition will be indicated. To remove the test indication, the connection to the ‘self-test’ terminal must be opened. A self-test fail indication due to a window fault will remain until a window ‘self-test’ is successful and will then unlatch after a 1 minute delay. The ‘self-test’ should not be repeated more frequently than every 20 seconds (to allow the ‘self-test’ circuitry to recharge) as erroneous results may occur. Note: that if a unit is poorly sited such that sunlight can reach the window test detector element, the receive amplifier may saturate.
In this event, that particular test is aborted and if this situation persists for 6 hours 40 minutes, the unit will register a fault condition. CAUTION: A REMOTELY INITIATED TEST WILL PRODUCE AN ALARM SIGNAL FROM THE DETECTOR IF THE TEST SHOWS THAT THE WINDOW IS CLEAN. TAKE THE NECESSARY STEPS TO INHIBIT A FULL ALARM CONDITION AT THE CONTROL PANEL BEFORE PROCEEDING. IF THE SELF-TEST CONNECTION IS NOT OPENED AFTER A SELF-TEST THE DETECTOR WILL REMAIN DISABLED. The window ‘self-test’ may be disabled by permanently connecting the ‘self-test’ terminal to 0V (pins 3 or 5) before power up.
This may be desirable in those conditions in which contaminants may make the window appear dirty but which may not affect the ability of the detector to otherwise function normally. The detector may be reset by reducing the voltage to less than 2 volts for greater than 0. 5 seconds. A remote LED may be used with the detector except for the S251i+ and S271i+ when the detector is used through a shunt diode safety barrier or galvanic isolator. A ‘self-test’ may be initiated remotely from the controller for the S271+ (dependant on MX firmware version). 1 6. PERFORMANCE CHARACTERISTICS 6. 1 GENERAL A large number of fire tests have been carried during the development phase of the S200+ Series detectors to determine their response limits. The results of these tests are summarised below. In order to appreciate their significance, an understanding of the mode of the operation of the detector is necessary, and a brief explanation follows: 6. 2 MODE OF OPERATION – BEHAVIOUR IN FIRE TESTS Flaming fires involving carbonaceous materials produce large quantities of carbon dioxide.
This part of the combustion process gives rise to a very high level of infra-red radiation in a narrow wavelength region centred upon 4. 3? m. The radiation from a fire flickers in a characteristic way and the detector uses this flicker signal in conjunction with the black body rejection technique described in Section A to discriminate between flame and non-flame signals. The level of the signal depends upon the size of the flame and its distance from the detector. For liquid fuels the signal level increases as the surface area of the burning liquid increases.
For any type of fire the signal level generally varies inversely with the square of the distance. For convenience, fire tests are normally carried out using liquid fuels burning in pans of known area in still air. Note: The results of fire tests can be significantly affected by weather conditions prevailing at the time, eg, – wind. The sensitivity of a detector can then be conveniently expressed as the distance at which a particular fire size can be detected. While the S200+ will reject modulated signals from blackbody sources, the presence of such sources of high intensity may affect the sensitivity of the detectors.
It is important to think in terms of distance rather than time because of the different burning characteristics of different fuels. Fig. C-5 shows the response to two different fuels which ultimately produce the same signal level. The signal level given by n-heptane quickly reaches its maximum and produces an alarm within about six seconds of ignition. Diesel, on the other hand, being less volatile, takes about a minute to reach equilibrium and an alarm is given in about 60 seconds from ignition. Note: 22
If a fire test is carried out using non-miscible fuels then it is strongly recommended that water be placed in the bottom of the pan to keep it cool and prevent it deforming. A sufficient amount of fuel must be placed in the pan to ensure combustion occurs over all of its area throughout the intended duration of the test. 2 a) 0. 1m N-HEPTANE PAN FIRE b) 0. 1m 2 DIESEL PAN FIRE c) 0. 1m 2 METHANOL/ETHANOL PAN FIRE a) c) ENERGY FROM FIRES a) and c) at 25m FIRE b) AT 15m ENERGY b) 0 10 20 30 40 50 60 TIME SECONDS Fig. C-5 Burn Characteristics of Pan Fires
The time taken by the fire to reach equilibrium depends on the initial temperature of the fuel. If diesel were to be pre-heated to a temperature above its flash point then its behaviour would be more like that of n-heptane at 25oC. The test data presented below refers to fires which have reached their equilibrium condition. 6. 3 FIRE TEST DATA The S200+ range has been tested by LPCB to BS EN 54 Part 10 : 2002 and classified as a Class 1 flame detector on the 50m and 25m range settings. The S200+ is certified as Class 3 on the 12m range setting. 6. 3. 1 N-HEPTANE
The most convenient fuel for fire tests is n-heptane since it is readily available and quickly reaches its equilibrium burning rate. The range figures specified in Para 5. 5 relate to a n-heptane fire in a 0. 1m2 pan on the main axis of the detector field of view. 6. 3. 2 OTHER LIQUID HYDROCARBONS Typical ranges achieved with other fuels burning on 0. 1m2 pans, relative to that for n-heptane, are as follows: Alcohol (Ethanol, Meths) Petrol 100%* 95% Paraffin, Kerosene, JP4 70%** Diesel fuel 52% * Test performed using meths in a 0. 25m2 pan. ** Test performed using paraffin.
The detection range is also a function of pan area. Field trials using n-Heptane fires indicate that the detection range increases by approximately 20% when the pan area is doubled. 23 Note: 6. 3. 3 When testing at the limits of the detectors range, the delay in response will vary due to the ambient conditions and may be significantly longer than the minimum response times, as described in 5. 6. GAS FLAMES The S200+ will not detect a hydrogen fire as it does not contain carbon. The S200+ will detect gas fires from inflammable gases containing carbon and hydrogen providing its flame produces flame modulation in the 1 to 15Hz ange. Fires burning a premixed air/gas mixture may be difficult to detect as they may produce little modulation. Tests show that an S200+ detector set to the 50m range will typically detect a 0. 8m high and 0. 2 sqm area methane/natural gas flame (venting from an 8mm diameter gas vent at 0. 5Bar (7. 5lbs/sq in) as below: Range 6. 3. 4 30m 40m 50m Time to Respond 3 seconds 6 seconds 15 seconds DIRECTIONAL SENSITIVITY WARNING: WHEN MOUNTING THE FLAMEPROOF VERSIONS OF THE S200+ DETECTORS, ENSURE THAT THE PARTS OF THE FLAMEPROOF GUARD INDICATED IN FIG.
C-6 ARE NOT DIRECTED AT THE RISK AREA BEING PROTECTED, AS THE FIELD OF VIEW IS RESTRICTED. MIRROR COVER DO NOT MOUNT THE FLAMEPROOF VERSION OF THE S200+ DETECTOR WITH THIS PART OF THE GUARD (WINDOW PROTECTOR) DIRECTED AT THE RISK AREA BEING PROTECTED. RESTRICTED FIELD OF VIEW DUE TO WINDOW GUARD METAL PROTRUSION 24 Fig. C-6 The sensitivity of the S200+ is at a maximum on the detector axis. The variation of range with angle of incidence is shown in (Polar Diagrams) Figs. C-7 and C-8 for open air tests using 0. 1m2 pan fires with the detector operating at normal range. 90 80 DETECTOR o PLAN VIEW 90 o