IFD-E(IS) Intrinsically Safe Flame Detector User Manual
Contents
1. does not need an external power supply Current drawn from the detector supply connections by the barrier itself is less than 500A Approved Safety Barriers For systems a generic specification for the barriers is as follows Any shunt zener diode safety barrier certified and approved to meet the ATEX Directives or CENELEC IEC standards ATEX group and category Ex II 1 G CENELEC IEC marking EEx ia Il C associated apparatus Having the following or lower output parameters Max output volts Wes 30V Max output current Pe 100mA Max output power Po 0 65W A number of barriers meet this specification and examples are given below Pepperl amp Fuchs Ltd DIN rail Shunt 300Q 77 Ripponden Road DIN rail Shunt 300Q X 2 Oldham DIN rail Shunt 300Q Lancashire OL2 8PF United Kingdom KFDO CS Ex1 51 DIN rail Galvanic X 1 www pepperl fuchs com KFDO CS Ex2 51 DIN rail Galvanic X 2 MTL MTL7028 DIN rail Shunt 3000 Power Court MTL7728 DIN rail Shunt 3002 Luton MTL7779 DIN rail Shunt 300Q X 2 Bedfordshire LU1 3JJ United Lingdom Active 3000 www mitl inst com MTL7706 DIN rail 4 20mA output Safety Earth Single channel and star connected A C safety barriers must be connected to a high integrity earth by at least one and preferably two copper cables each of cross sectional area of 4mm or greater The connection must be such that the impedance from the connection point to the main power system earth is less than2. explosive atmospheres General requirements Hazardous areas are common in petroleum and chemical engineering plants and in factories processing and storing gases solvents paints and other volatile substances Electrical equipment for use in these areas needs to be designed so that it cannot ignite an explosive mixture not only in normal operation but also in fault conditions There are a number of methods available to achieve this oil immersion pressurised apparatus and powder filling for example but the two most common used are flameproof enclosures and intrinsic safety Flameproof equipment is contained in a box so strong that an internal explosion will neither damage the box nor be transmitted outside the box The surface must remain cool enough not to ignite the explosive mixture When flameproof equipment is interconnected flameproof wiring must be used This method is most valuable when high power levels are unavoidable but it is not acceptable for areas in which an explosive gas air mixture may be continuously present or present for long periods For this reason these flame detectors are made intrinsically safe rather than flameproof Intrinsically safe equipment operates at such low power and with such small amounts of stored energy that it is incapable of causing ignition gt In normal conditions gt With a single fault for ib type of protection code gt With any combination of two faults for ia type of protection
3. of Li 0 EN50 039 Provided that the peak voltage of any circuit contained within the muticore does not exceed 60 volts Terminal 5 with respect to terminal 6 NOTE 6 Terminal 7 with respect to terminal 8 lf required a loading resistor of not less than 3k 0 5 watt and Ui 30V having a surface area between 20cm and 10cm may be connected between the terminals of any circuit but not between li 100mA circuits 2 3 0 809 ISS2 JULO7 Hochiki Europe UK Ltd 11 HOCHIKI World Class Leaders in Fire Detection since 1918 Hochiki Europe UK Ltd Grosvenor Road Gillingham Business Park Gillingham Kent ME8 OSA England Telephone 44 0 1634 260133 Facsimile 44 0 1634 260132 Email sales hochikieurope com Web www hochikieurope com Hochiki Europe UK Ltd reserves the right to alter the specification of its products from time to time without notice Although every effort has been made to ensure the accuracy of the information contained within this document it is not warranted or represented by Hochiki Europe UK Ltd to be a complete and up to date description Please check our web site for the latest version of this document 2 3 0 809 ISS2 JULO7
4. one ohm Intrinsically safe circuits in the hazardous area should be insulated from earth and must be capable of withstanding a 500V RMS A C test voltage for at least one minute When using armoured or copper sheathed cables the armour or sheath is normally isolated from the safe area busbar 2 3 0 809 ISS2 JULO7 8 Hochiki Europe UK Ltd Wiring and Cable Types It is not permitted to connect more than one barrier circuit in the hazardous area to any other circuit Both separate and twin cables may be used A pair contained in a type A or B multicore cable as defined in clause 5 3 of EN50 039 may also be used provided that the peak voltage of any circuit contained within the multicore does not exceed 60V The capacitance and either inductance or the inductance to resistance L R ratio of the hazardous area cable must not exceed the parameters specified in Table 6 The reason for this is that energy can stored in a cable and it is necessary to use cable in which energy stored is insufficient to ignite an explosive atmosphere To calculate the total capacitance or inductance for the length of cable in the hazardous area refer to Table 7 which gives typical per kilometre capacitance and inductance for commonly used cables Note The flame detectors have zero equivalent inductance L 0 and a 0 03uF capacitance C 0 03uF essee im pe fe Capacitance uF Inductance mH L R ratio uH ohm Capacitance uF km
5. Conductor Sheath Inductance Cable Type resistance core Resistance p ohm km core giau to ohm km sheath MICC Pyrtenax light duty MICC Pyrotenex heavy duty Pirelli FP200 PVC sheathed and Insulated to BS6004 Table 7 Examples of electrical characteristics of cables commonly used in fire protection systems Maximum Loading of IS Circuit Because of the finite resistance of the safety barrier there will be a limit to the current drain which can be tolerated before the voltage on the circuit falls outside the specified limits for the IS detector The standing current for the detectors can be calculated by the sum of the individual selected detector currents as given in the detector data sheet This may limit the maximum number of detectors per barrier to two or three 2 3 0 809 ISS2 JULO7 Hochiki Europe UK Ltd 9 Installation It is important that the IS 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 convenience where continuity of a cable sheath or similar is required Service amp Repairs Servicing of IS flame detectors may be carried out only by a BASEEFA or equivalent authorised body In practical terms this means that IS flame detector may be serviced only at the manufactures factory Servicing of the fire protection system should be carried out as recommended by the local regul
6. IFD E IS Intrinsically Safe Flame Detector User Manual r HOCHIKI 2 Hochiki Europe UK Ltd Description This Installation Guide gives information on the intrinsically safe S version of the flame detectors that have been approved by BASEEFA British Approvals Service for Electrical Equipment in Flammable Atmospheres The requirements of the European Community Directive 94 9 EC the ATmosphere EXplosives ATEX Directive have been met The approval have been accessed to European Standards EN 50014 EN 50020 and EN 50284 The detectors are certified Ex Il 1G EEx ia llC T4 and can be used with all listed gases The range comprises single infra red IR dual infra red IR and triple infra red IR flame detectors The detector housings are available in zinc metal alloy or stainless steel and also stainless steel antistatic glass filled polycarbonate The guide also provides information on intrinsic safety the application maintenance installation and adjustments of the detectors Reference to other individual detector publications can be made for more information on none intrinsically safety issues These publications are available on request Introduction to Intrinsic Safety There are many places where an explosive mixture of air and gas or vapour is or may be present continuously intermittently or as a result of an accident These are defined as hazardous areas by BS EN 50014 1998 Electrical apparatus for potentially
7. ation in force 2 3 0 809 ISS2 JULO7 10 Hochiki Europe UK Ltd IS System Drawing Hazardous Area Safe Area Safe Area Apparatus Unspecified except that it must not be supplied from nor contain under normal or abnormal conditions a source of potential exceeding 250V RMS or 250Vd c with respect to earth IFD E IS 1 l 24Vd c Normal Barrier Break supply to reset if detector is set to latch 2 IFD E IS 24Vd c Normal Break supply to reset if detector is set to latch Barrier 2 channel Zone NOTE 1 Each Barrier fed circuit must be a separate circuit and must not be connected with any other electrical circuit NOTE 2 The electrical circuit in the hazardous area must be capable of withstanding an AC test voltage of 500 volts RMS to earth or frame of the apparatus for one minute NOTE 3 The installation must comply with national installation requirements for example to EN 60079 14 Detector Input Parameters NOTE 4 The capacitance and either the inductance or the inductance to Terminal 1 with respect to terminal 2 resistance L R ratio of the hazardous area cables must not Terminal 3 with respect to terminal 4 exceed the maximum permissible parameters for the required Ui 30V groups IIA IIB and IIC li 100mMA NOTE 5 Pi 0 65W The cable may be separate cables or a twin pair contained ina Ci 0 03uF type A or a type B multicore cable as defined in clause 5 3
8. code In any of these conditions every component must remain cool enough not to ignite gases for which it is approved See Table 2 Classification of Hazardous Areas EN 50014 states that electrical apparatus for potentially explosive atmospheres is divided into gt Group Electrical apparatus for mines susceptible to fire damp gt Group II Electrical apparatus for places with a potentially explosive atmosphere other than mines susceptible to fire damp 2 3 0 809 ISS2 JULO7 Hochiki Europe UK Ltd 3 These flame detectors are designed to meet the requirements of Group Il apparatus For the type of protection i intrinsically safe Group Il is subdivided into Equipment Categories Type of Explosive Atmosphere Table 1 Type of Protection Code Table 2 Temperature Class Table 3 and Gas Group Table 4 Equipment Markings ATEX EU Directive 94 9 EC CE Marking EU Explosive Atmosphere Symbol Group 2 Type of Explosive Atmosphere Group II Equipment Category ECU SH G gas vapour mist very high level of protection in which explosive atmosphere mixtures of air gases vapours or mist are present continuously for long periods normal level of protection in which explosive atmosphere mixtures of air and gases vapours or mist are unlikely to occur and if it occurs it will exist only fora short period high level of protection in which explosive atmosphere mixture of 1 air and ga
9. ecommended for general use Galvanically Isolated Barrier Galvanically isolated barriers also Know as transformer isolated barriers differ from conventional shunt zener barriers in that they provide electrical isolation between the input safe area and the output hazardous area This is achieved by the use of a D C D C converter on the input side which is connected to the hazardous area through a voltage and power limiting resistor zener combination similar to a conventional barrier The galvanic isolation technique means that the circuit does not need a high integrity safety earth and that the intrinsically safe circuit is fully floating Earth leakage problems for control and indicating equipment are therefore eliminated if this type of interface is used 2 3 0 809 ISS2 JULO7 Hochiki Europe UK Ltd 7 Galvanically isolated barriers are widely used with conventional flame detector systems If the system is of an addressable type with signal pulses on the supply lines then the response time of most standard barriers will be too slow to allow their use In these applications special galvanically isolated barriers are required that can freely transmit the required protocol pulses without introducing severe voltage drops These interfaces are available as single or dual channel versions and are recommended for any application in which direct earth connections are not acceptable The galvanically isolated barrier is a two wire device which
10. insically Safe Flame Detector Voltage 14 to 30Vdc Alloy Housing Current AQUA typ 24V IN Polarity sensitive The flame detectors respond to light Optional Output Terminals 3 amp 4 emitted from flames during combustion Voltage OV to Supply In O C The detectors discriminate between flames Current 2 4mA typ Internally Limited and other light sources by responding only Optional Relays Terminals 3 to 8 to low frequency flickering produced by Contact Ratings flames typically 1 to 15Hz The detectors Voltage 30Vdc Max ignore fixed light sources and rapidly Current 1 Amp Max flickering illumination predominantly Resistive Loads Onl produced by lighting The flame flicker techniques have the advantage of still allowing the detection of flames through a thin layer of oil water Environmental vapour ice or dust This makes these detectors particularly useful in industrial applications Operating Ambient Temperature 20 C to 40 C T4 Full details of the principles of operation Check detector 20 C to 85 C T3 electrical description and other detailed limits technical data are published in the products ATEX Ex I1 G individual data sheet Approval Category CENELEC IEC Marking EEx ia IIC T4 Apparatus 2 3 0 809 ISS2 JULO7 6 Hochiki Europe UK Ltd System Design Engineers familiar with codes of practice for hazardous area systems should only undertake the design of an intrinsically safe fire detec
11. ore the lowest cost Being passive devices they also impose the minimum of restrictions on the operation of the flame detectors Thus single channel barriers are available either as positive or negative polarity where the polarity refers to the polarity of the applied voltage relative to earth The significance of this is that one side of the barrier must be connected to a high integrity safety earth Although this connection has no effect on the operation of the flame detector and is not needed for their correct operation it may not be acceptable to the operation of the control and indicating equipment This is particularly true if the control equipment incorporates earth leakage monitoring and even without this feature the earthing of the loop may cause unwanted cross talk between loops If the earth connection is not acceptable then the A C or isolating barriers should be used Star connected A C Barrier A C barriers are also passive devices and must still be connected to a high integrity safety earth However they are designed to allow either positive or negative voltages with respect to earth and under normal conditions provide a connection to earth via a reverse diode rather than directly The disadvantage of this type of barrier is that the end to end resistance is nominally 12000hms compared with the 300 ohms of the single channel type This high resistance results in an extra voltage drop in the circuit This type of barrier is not r
12. ses vapours or mist are likely to occur These Flame Detectors are suitable for all the above equipment categories Note The detectors are not certified for explosive dust atmospheres Table 1Equipment Categories and Type of Explosive Atmosphere Group II 2 3 0 809 ISS2 JULO7 4 Hochiki Europe UK Ltd CENELEC IEC E Ex ia HC T4 Conforms with European Standards IEC marking omits this character Explosion Temperature Protection Class Symbol Referred to ambient of 20 C to 40 C Maximum Surface Temperature Type of Code Protection piles Code gory Intrinsic safety 3 T1 These Flame Detectors are approved ia Table 2 Type of Protection Codes a 450 C Detectors approved to T4 at 40 C Table 3 Temperature Classifications esc Reese ces Orcas torean 300 C Butane Methanol Petroleum Propane Styrene These Flame Detectors are approved IIC for listed gases in EN 50014 Table 4 Subdivisions of Group II Gases 2 3 0 809 ISS2 JULO7 Hochiki Europe UK Ltd 5 Intrinsically Safe Product Technical Data Housing Material Die Cast Zinc Alloy See Fig 1 Housing Colour Blue typical Housing Height 142mm Dimension Width 108mm Excluding Mount Depth 82mm Cable Gland Entries 2 X 20mm Supply In Terminals 1 amp 2 Voltage 14 to 30Vdc Current 2 to 30mA See datasheet for detail Fig 1 Polarity sensitive Optional Input Terminals 3 amp 4 Intr
13. tion system In Europe the standard is EN 50014 Electrical apparatus for potentially explosive atmospheres General requirements The fire detector performance is the same as the standard none intrinsically safe counterparts Performance information given in standard product guides is therefore applicable to the intrinsically safe range The BASEEFA certification of the intrinsically devices covers their characteristics as components of an intrinsically safe system This indicates that the flame detectors can be used with a margin of safety in such systems In safe area standard applications it is some times desirable to connect the wiring as a loop with both ends terminated at the control panel In the event of an open circuit fault it is then possible to drive both ends simultaneously In a hazardous area it is not possible to use a loop configuration because the potential to feed power from each end of the loop would double the available energy in the hazardous area and contravene the energy limitations of the intrinsically safe certification All circuits must therefore be connected as spars from the safe area or as radial connections from the control panel Types of Safety Barrier The system configuration can for three types of safety barrier each of which has its own advantages and disadvantages A brief outline of the characteristics is given below Single Channel 28V 3000 Barrier This is the most basic type of barrier and theref
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