GDS 2010 - Ribble Enviro Ltd
Contents
1. Shut off the calibration gas CALIBRATION WHEN USING CV TRANSMITTER 4 20mA DEVICE Where a sensor CV transmitter has been supplied the setting up procedure as described on pages 17 or 18 should be followed Alarm level adjustment The alarm level is factory set at the level stated on the instrument test certificate To adjust the gas alarm level 1 For toxic flammable gases zero the instrument in clean air using the zero potentiometer for ambient oxygen monitoring the meter should be adjusted to read 20 8 using the calibration potentiometer 2 Press the alarm set switch for approximately 5 seconds the sounder will bleep and the low alarm indicator will come on the green power indicator will turn off release the alarm switch 3 Using the zero potentiometer adjust the digital display for the required low trip level reading press the alarm set switch until the high alarm indicator comes on release the alarm set switch 4 Adjust the digital display to read the required high trip level reading and again press the alarm set switch the overrange indicator will come on Adjust the digital display to read the required overrange trip level Press the alarm set switch again all three alarm indicators will come on 5 Zero digital display toxic flammable or 20 8 for oxygen and press alarm set switch alarm indicators will turn off and the green power indicator will turn on OPERATION On power up the green power indicator will2. DI TP4 1P3 SENS VOLTS ON ZERO o 00 JP1 Jumpers AC 3 Wire Source 1 i EExd SENSOR BOARD w YP SENSOR 2 D 18 Fig 6 C284 CV TRANSMITTER TOXIC OXYGEN TECHNICAL Input voltage Output Standard 12 30v DC 24v nominal Option 1 5v output solder G Alarm relay board options safe area board only Mains relay S P C O 5A 230v AC Analogue 4 20 ma 250 ohms max source 3 wire system only 2 wire if the 4 20mA signal is not used Signal relay contacts S P C O rated 1A 24v Logic and fire panel signal only Trip Indicator LED trip point selectable 10 to full scale Fire Alarm panel signalling cut F Logic output JP3 position L and end of line link JP4 Full board safe area board only On board sounder Auxiliary output DC volts standard as input volts 24v selection by fixed voltage regulator U5 5 12 15v DPM gas readout display zero and span potentiometers used only for DPM setting INSTALLATION Siting of the equipment should be chosen with regard to the following points a Away from sources of heat and with room for adequate air circulation b Within easy reach for operating and maintenance personnel c Connecting cables to be electrically shielded i e M I C C steel wire armoured screened cable or steel conduit Note Sensor cables should not be run in the same ducting
3. Gas Alarm Card Facilities Digital Panel Card Alarm set Overrange alarm High Lo Fault Inhibit Power on Reset Inhibit Calibration Zero Test Rack Detail HALF RACK FULL RACK Front 132 lt 270mm gt a 482mm gt lt _ __ 232mm gt a _ 445mm 210 Plan O R33 Jumper Terminals J9 J3 J4 Fig 2 Alarm Card Component Detail sexs 5 VOLTS T ass o00000000n o o S ooo0oo00000 RE alee c e M Manual alarm relay reset A Auto alarm relay reset ie ot Q o R34 U3 o 24V DC sensor supply 4 20mA transmitters P Adjustable senor supply pellistor only V Voltage output I 4 20mA output 0000 da No ng ee 3 dofofo o jt 05 9 3 aR o al GE SO AATE o g NE je gt sj o a ran POSM ISS EW Low Auto Auto reset low alarm Mute Sounder 02 Oxygen Monitor OR zA D De energised E Energised F Facilities Card Component Detail SOUNDER MUTE 22 SOUNDER DELAY ON OFF RELAYS 1 1 000 000 E D HIGH LOW 1 RESET M A Jumper Terminals ON OFF M Manual alarm relays reset link 1 amp 2 A Auto alarm relays reset link 2 amp 3 E High common relay normally energised link 1 amp 2 D High common relay normally de energised l
4. Connecting cables to be electrically shielded i e M I C C steel wire armoured screened cable or steel conduit Note Sensor cables should not be run in the same ducting as power cables SET UP 1 Having powered up allow 5 minutes for the sensor to stabilise 2 SAFE AREA SENSOR BOARD the sensor current voltage should be set by connecting a voltmeter mV range across TP3 TP4 and adjusting the sensor voltage potentiometer 10 turn until the required voltage reading is obtained mV meter reading mA sensor current CAUTION DO NOT EXCEED 360mV mA EExd SENSOR BOARD measuring across sensor terminals W and P adjust the sensor voltage potentiometer for required voltage 3 Zero the card in clean air by adjustment of the potentiometer marked zero until the GREEN ON Z LED just turns from GREEN RED to GREEN At this point the output will 4ma If you require to check this connect a digital meter mV range to the test pins marked TP1 and TP2 if adjustment is required adjust the 4ma potentiometer 4mV 4mA s A fa Output Signal Adjust KON CV TRANSMITTER Sensor TP3 Volts TP4e NC Field Terminals E p W Ysia p o TP2 TP1 e LS loo i HO Sensor are c JEO NO O volts adjust Sensor Sounder lt Pw Aux
5. Output WY P Sensor Terminal FULL CV BOARD SAFE AREA SENSOR BOARD With the digital meter connected to the test pins TP1 and TP2 and a reading of 4mV clean air apply test gas and wait until a maximum reading is obtained if necessary adjust the 20mA potentiometer for the required mV reading for the calibration gas being used Where 4 to 20mA span 0 100 L E L Lower explosive level and the sensor is to be calibrated for Methane which has an L E L of 5 vol when using 1 Methane in air test gas 20 L E L a reading of 7 2mv 7 2mA would be required Where a digital panel meter is fitted readings should be taken directly from the readout and if necessary adjusted using the 4 and 20mA potentiometers ADDITIONAL RELAY BOARD ALARM TRIP POINT ADJUSTMENT This level will normally be set at 20 of the range reading i e 7 2mA 1 Connect the DVM as above using the zero potentiometer adjust for the required trip level mv 2 Adjust the alarm level potentiometer until the relay just changes state 3 Using the zero potentiometer re adjust the DVM to 4mV The above adjustment may be carried out in house by connecting the CV transmitter directly to a DC power supply C V TRANSMITTER E 2 Wire JP1 JP1 Jumpers AD i i Loop SIG Powered 7 100R H JP1 Jumpers DB i i l SIG 3 Wire Sink
6. Unit Transmitter Y Ysa LI Sensor INFRA RED SENSOR 3 WIRE Gas Detector Control Unit Transmitter A Or H Sensor RED ident flammable TOXIC OXYGEN YELLOW ident WY toxic ove BLUE ident oxygen o Y GREEN ident G others SENSOR TECHNICAL Input Voltage Current Output Standard Sensor Cable Alarm Relay Board Options safe area board only Full Board Options safe area board only INSTALLATION Siting of the equipment should be Fig 5 C323 CV TRANSMITTER FLAMMABLE 12 30v DC 24v nominal Nominal 160ma Analogue 4 20 ma 250 ohms max Option 1 5v output solder C 3 core 1 5mm screened maximum cable loop resistance 20 ohms Relay contacts S P C O rated 1A 24vDC 0 5A 120vAC option SA 230vAC Trip Indicator LED trip point selectable 10 to full scale Fire Alarm panel signalling Remove LK1 Logic output JP1 position L and end of line link JP2 normally set at A analogue On board sounder Auxiliary output DC volts standard as input volts 24vDC selection by fixed voltage regulator U5 5 12 15 volts DPM gas readout display DPMZ and DPMS potentiometers used only for DPM setting 3 wire source mode standard chosen with regard to the CALIBRATION following points a Away from sources of heat and with room for adequate air circulation b Within easy reach for operating and maintenance personnel c
7. as power cables CALIBRATION 1 Connect a digital voltmeter millivolt range to the and test terminals 2 wire system or X and Y test terminals 3 wire system For 3 wire systems the CV is preset in the current source mode 2 In clean air check that the DVM reads 4mV if not adjust the 4mA potentiometer on the CV transmitter board 3 Apply test gas and wait until a maximum DVM reading is obtained if necessary adjust the 20mA potentiometer for the required mV reading for the calibration gas used see range reading on test certificate or printed on the CV circuit board 4 For oxygen level monitoring remove the sensor terminal connector from the PCB J4 and adjust the 4mA potentiometer for 4mA 4mv 9 Alarm Level Adjust LL Output Signal JP2 No C No Adjust RELAY BOARD 6 6 6 aj gt Test Points CV TRANSMITTER Field Terminals to Alarm Unit Sensor NC Terminal Cc wyR J4 EIT NO Sounder ele lolele Aux WYR Output Sensor Terminal FULL CV BOARD 40J e wo Reconnect the cell and allow reading to stabilise adjust the DVM reading for 17 3mA 20 8 Vol ambient oxygen using the 20mA potentiometer Where a Digital panel meter is fitted readings should be taken directly from the readout and if required adjust
8. be to ensure the day to day operation of the system and to lay down the procedure for dealing with a gas alarm or fault warning To ensure reliability an agreement should be negotiated for regular servicing When a service contract cannot be arranged an employee with suitable experience of electrical equipment should be trained to deal with the basic servicing and instructed not to attempt to exceed the scope of such training Liaison should be established with those responsible for maintenance of the building fabric or redecoration etc to ensure that their work does not cause a fault or otherwise interfere with the operation of the gas alarm installation Particular attention appertaining to the Detector Head The operating instructions should be kept available preferably with the control unit all faults service tests and routine attention given should be recorded DAILY A check should be made that any fault condition which may be indicated is in fact being attended to and that all other indicators are normal WEEKLY In plants involving a high risk process or having gases which may cause loss of sensitivity a check on calibration should be carried out TWICE YEARLY MAINTENANCE SCHEDULE All zeros at the control unit to be checked logged and aligned Each detector to be gas tested and reading logged sensitivity checked Field indicators to be tested All alarm set points checked and re aligned Lamp Test All faulty parts replaced
9. where required All filter elements checked and replaced as necessary Power supply complete functional check Visual inspection made to confirm that all cabling fitting and equipment is secure undamaged and adequately protected Sea eS oS ee SS ACTION TO BE TAKEN IF THE APPARATUS ALARM SOUNDS A Extinguish all naked flames including all smoking materials B Turn off all gas appliances C Do not switch on or off any electrical lights or appliances D Turn off the gas supply at the gas emergency control and or with L P G supply the storage tank E Open doors and windows to increase ventilation If the alarm continues to operate even after an alarm re setting action where appropriate and the cause of the leak is not apparent and or cannot be corrected vacate the premises and immediately notify the gas supplier and or the gas emergency 24 hour service in order that the installation may be tested and made safe and any necessary repairs carried out FAX BACK SHEET SERVICE MAINTENANCE PLAN 0113 287 8178 TECHNOLOGIES LTD GDS Technologies can offer comprehensive maintenance amp service cover on all of your gas detection systems Should you require further details please complete and fax return this document for an immediate response Company Address Site Location if different from above if known No of Sensors For telephone inquiries your contact is Julie Mitchell 0113 286 0166 GDS Te
10. C931 Manual No ARW 105 7 Issue A TECHNOLOGIES LTD GDS2010 SERIES MODULAR GAS ALARM OPERATING HANDBOOK www gds technologies co uk Tel 44 0 113 286 0166 Fax 44 0 113 287 8178 Email sales gds technologies co uk Contents BLS GINO ERE EE EN 3 5 TECHNICA Speed vvs ses ede 6 MANNS 7 8 ENE 9 10 Service Routine Attention uasemsmengjemetnievvjhdi usideikdkdsne 11 Table oft Lower Explosive LIMIS cscs baited ca rccedilintasiniaansusicaiititinsuiees eden ee iheciteieimancecuala 13 ILLUSTRATIONS Fig 1 Alarm and Facilities Card front panel 2 suureusesemmunessuummmm anne 14 2 Circuit Board controls JA ONaseeene 15 3 Alarm and Facilities Card terminal connections mmemsssvsraarsnnnsannnnenrenkknvnnerannvnne 16 4 Sensor Connection dead 17 5 CV Transmitter Flammable sca bcectedaectierieretal aed sedaswatilebeadieadanctse eee aaa 18 6 CV Transmitter TOXIC OXYGEN ssissrsii iiidid diania aaa a iaai 18 SYSTEM DATA Paneera Mons Grr Nan Sop m m G A Rae Pid low alarm p High alarm trip Details This document is non contractual and the equipment specification and detail may be modified at any time without prior notice DESCRIPTION The GDS 2010 has been designed with features that will provide an effective response to the detection and control of hazards in a wide range of industrial environments from boiler rooms to offshore petrochemical installations The system is offe
11. able fault short or open circuit control circuit malfunction ALARM RESET Alarm circuits can only be reset when the hazard has cleared SYSTEM ELECTRICAL TEST The unit may be electrically tested by pressing the test pad for 15 seconds after which the alarm indicators and sounder will activate intermittently maintaining pressure on the pad for a further 15 seconds will result in constant indicators and activation of alarm relays full system test To ensure that the system responds correctly to the presence of gas the sensor should be exposed to test gas It is advisable to carry out this test at six monthly intervals ALARM INHIBIT DELAY From the application of power a period of 60 seconds applies during which alarm relays and indicators are held in the normal operating condition inhibited This period is indicated by the green power on indicator flashing and allows for sensor stabilisation ALARM RELAY INHIBIT During servicing alarm relays may be isolated by pressing the reset pad for 15 seconds after which the inhibit indicator will come on indicating inhibit mode to remove inhibit press the reset pad for 15 seconds the inhibit indicator will turn off POWER ON INDICATOR Green L E D power on flashing constant after 60 seconds ANALOGUE OUTPUT 4 20mA into 250 ohms max load Optional 1 10V output Technical specification All relay contacts used to switch inductive loads relays etc should hav
12. chnologies Ltd Fusion Point Ash Lane Garforth Leeds UK LS25 2GA Tel 44 0 113 286 0166 Fax 44 0 113 287 8178 E Mail sales amp gds technologies co uk Table of lower explosive limits L E L The figures quoted below are taken from British Standards Institute publication BS 5354 Part 1 1976 and show the L E L of some of the more common gases and vapours GAS L E L VOLUME ADP vasre Fee atau dios bec EEE E EE eciadaline diye 2 1 AMMONIA cers e eE e E E EE 15 0 PEN 1 2 EE LT xacavchsusninemsacovacsndencimanseameaceeodauauarsnenheentacavedsaseenienebeeatsnaceeabseseimenieeanaeacan 1 5 Carbon 10160410 EE EEE EEE 12 5 Sa EEE RE Eel tance ceili ala aba 2 7 MAE vrede 1 1 gt AE cnn E N Bier ir pertain terete nee OG 1 2 ge LE 4 0 LE LEE ER EEE EE EN ENE 5 0 POPE v4o4esuasGagrsremdkeumnmunued jevnet 2 0 2111 EE EEE OE EN EE emacs EE 1 4 TOIUENE EE EE E EE RRE OEE AEri 1 2 EEE 1 0 Table of occupational exposure limits P P M The figures quoted below are taken from guidance note EH40 from the Health and Safety Executive GAS 8 HOUR T W A P P M Hydrogen sulphide sareren a eE EEEE E RERNA EEE 5 Carbon 10610002 EE EE E mart 30 TT 2 Nitrogen MONGUTE siririna eivind 25 NOGEN OIG aise A AT E 3 COME Ve 0 5 1 ER EN siwudunkeluandniulaniie 25 OZONE EE EEE EN ee 0 1 Ethylene Oxide aaa cs can sanrrnielntbeheentettaaadeanioi nna taitmcie Meeemand Sek cadansaataa ast cecbbnebvenauecaanensh 5 Fig 1 Module Detail
13. e suppressors fitted typical device Farnell 772 756 POWER REQUIREMENTS DC 24v nominal operating range 21 to 32v AC 110 230 6 50 Hz POWER CONSUMPTION 2 5w per module normal operating condition 5W per module full alarm condition SENSOR CURRENT 150 to 550mA adjustable constant current drive no field adjustment required SENSOR CABLE Catalytic 3 core 1 5mm screened M I C C S W A maximum cable loop resistance 20 ohms Toxic Oxygen 4 20mA 3 core 0 5mm screened M I C C S W A maximum cable loop resistance 200 ohms TERMINALS Screw type accepting up to 2 5mm cable RELAY OUTPUTS All relay contacts used to switch inductive loads relays etc should have suppressors fitted Typical device Farnell 772 756 ALARM CARD Alarm Low Latched or S P C O N D or N E Alarm High auto reset S P C O N D or N E Factory set N D latched Fault Alarm S P C O N D or N E All contacts rated at 5A 230v AC FACILITIES CARD Common Alarm Low S P C O N D or N E Common Alarm High Latched or S P C O N D or N E Factory set N D latched Overrange Alarm auto reset S P C O N D or N E Fault Alarm S P C O N D or N E Analogue Output 4 20 mA into 250 ohms max load Optional 0 10v ENVIRONMENTAL CE Cert No C587 Ambient Operation Temp 0 50 degrees centigrade Storage temperature 20 degrees to 60 degrees centigrade Humidity range 0 90 RH DIMENSIONS Alarm and Facilities Module 3U high 6E w
14. ed using the 4 20mA potentiometers ADDITIONAL RELAY BOARD ALARM TRIP POINT ADJUSTMENT This level will normally be set at 20 of the range reading i e 7 2mA 1 Connect the DVM as above using the 4mA potentiometer adjust for the required trip level 2 Adjust the alarm level potentiometer until the alarm LED just comes on 3 Using the 4mA potentiometer re adjust the DVM to 4mV The above adjustment may be carried out in house by connecting the CV transmitter directly to a DC power supply Should a full board be required to operate on a 2 wire loop then the relay must be disabled remove JP2 Gas Type Programming Works preset CO H2S SO Ho remove R4 R6 R15 R28 R29 R10 HCN remove R4 R6 R8 R15 R28 R29 R10 NO CLo Og remove R4 R7 R11 R28 R29 R10 NO HCL C2H40 Remove R3 R4 R6 R12 R15 R28 R29 R10 Oo Remove R3 R8 R6 R15 R42 R43 IC U2 NH3 Remove R3 R4 R6 R12 R15 R28 R29 R10 R8 19
15. flash for 60 seconds indicating that the sensors are stabilising during this period all alarms are held in the off condition After the stabilisation period any gas detected by the sensor will be indicated on the digital display with any alarm level being exceeded resulting in the sounder and appropriate red L E D and relay activating Pressing the reset pad will result in the sounder being silenced alarm indicators and relay may only be reset when the indicated gas level has reduced to below that of the alarm trip points SENSOR SUPPLY ADJUSTMENTS CATALYTIC SENSOR The sensor supply is factory set and requires no further adjustment where adjustment is necessary the following procedure should be carried out For ease of setting measurements are taken across a 1 ohm resistor located on the alarm card which is connected in series with the supply to the detector head Current required by each type of sensor is VQ21 300mA VQ23DCP 335mA therefore measuring mV across the 1ohm resistor at test points TP5 Ov and TP7 will provide a mV reading proportional to mA s supplied Adjustment may be carried out using potentiometer RV6 sensor supply adjustment Alternatively the sensor voltage may be set at the detector head across terminal P and W VQ21 2v VQ23DCP 2 5v Service routine attention The owner or occupier of the premises should place the supervision of the system in the charge of a responsible executive whose duty it should
16. ide 160mm deep Installation The GDS 2010 Series control instrumentation is designed for installation in a safe area only Siting of the instrument should be chosen with regard to the following points a Away from sources of local heat and with room for adequate ventilation b Within easy reach and audible distance of operating personnel c Convenient to a separately fused power supply d Incoming sensor cables and outgoing alarm annunciation e Sensor cables to be electrically shielded i e M I C C steel wire armoured screened cable 3 core 1 5mm To prevent any effect from earth currents the cable shielding should be grounded at one end only The instrumentation should be subjected to a minimum of vibration and shock Ascertain the voltage rating of the power supply to which the instrument will be connected SITING THE SENSING HEADS A key feature of the installation is the correct siting of the sensing head Several considerations must be taken into account the most important being the density of the gas Density air 1 ACEtone davesivciciinainscinirnvennsavedernanaes 2 0 n Hexane errrnrrnnrnrevnnevernrersrevvnenn 3 0 AMMONIA icase ei einni 0 6 HyYArOJE M dipiin asina 0 1 Peres 2 8 Methane rrrnrnrnnnnnnnrnrnevnrennnrsennne 0 6 n Butane kumaasokmduitede 2 0 n Octane Jaga Gem 3 9 Carbon monoxide rrrrrrrrvnnnnnrn 1 0 n Pentane rrrurrnnverarernrevnnnrnnunne 2 5 Eg O oorte
17. ienei 1 0 RSP ROD ANG eiiiai 1 6 Ethyl alcohol sxscsccessietvececcceisamaanas 1 6 TOWN GAS inniinn 0 4 0 7 n Heptane Luvuaedninannie id 3 5 NON E 3 7 Under still air conditions a lighter than air gas such as methane leaking from a small orifice at ground level will rise in a plume the shape of which approximates an inverted cone As the gas rises it draws air from the surroundings and creates a turbulence Resulting from this there occurs rapid dilution and unless a sensor is positioned within the plume there will be no initial indication of a leak As gas continues to escape the diluted concentration rises to ceiling level and begins to layer In time the concentration at ceiling level will increase and this in turn will displace air downwards Dangerous levels will therefore tend to occur at ceiling level and the thickness of this layer will increase with the passage of time When installing apparatus in explosive atmoshpere hazardous areas you must be aware of the requirements of BSEN60079 BSEN50014 IEC61241 Ventilation of the room will of course alter the situation significantly but it should be remembered that if the ventilator is not at ceiling level a dangerous concentration can still occur between the top of the ventilator and the ceiling For heavier than air gases such as propane or butane the formation of dangerous layers occurs at ground level These gases tend to behave like water and will run dow
18. ink 2 amp 3 E Low common relay normally energised link 1 amp 2 D Low common relay normally energised link 2 amp 3 Factory set normally de energised Factory set normally de energised Factory set manual reset High common relay delay 2 minute delay of relay action following an alarm Factory set off 15 Aejay jes 1261249 9 op D LL ejey eee 7 r i i i Ul OV i i I indy ai SS mea 4 Ov SUEN I Lee ee J L SNOILOANNOO TVYNINYIL 71314 G3d5YUVHO AYALLVE AG GNVLS SAILIMOVA NGV IV OIN O N 6 Auayyeg g Z oml 9 wejsuey 9 O N rv ul A OV MOT F Aeneg L ETE N M J A sInpoN Aepeg Aq pueys ayes WJe e SUOU dn paJamod ul MEIP SJOBIUO We SAOWSY SINPON MOUA O N Aejoy une4 9 O N Aejay 24 19M0dq Aejoy wey moq y 9 Aejay wey abuey 1940 9 Aejay wey U IH zY 9 O N OU S USE 4q dwe JeSaH 20v 8jOWaH UOWWOD 6 8 Z 9 S v c L X M A ainpoy senioe4 16 doo7 anoway asjnpoy o u A OG 4 OIN Aejoy nes 9 O N d o leuy NANO WWOZ 4 VC yeuy O N 6 Aejoy Wel MO LY 9 8 O N Z d 9 p s mod Aw JOSUAS A G dooj ywoz r M v ndu n ojeuy OIN Aejoy wey ublHev 9 Z O N L syoes JEYLN4 DU S Yse 4 due X JESaY D0V BJOWW9Y UOWWOD A aInpoy wey Fig 4 SENSOR 3 WIRE Gas Detector Detector Head Control Unit V pellistors or 3 wire CV BY SIG m SENSOR 2 WIRE Gas Detector CV Control
19. n gradients and pool at the lowest point The number of heads required in individual rooms is determined by the number of possible hazards in the vicinity Gas leakage may occur around valves flanges and anywhere where gas pipes are jointed It may be possible to cover several probable gas leaks in one room by the careful siting of a single head Cable ducts trenches and manholes are also likely places where a build up of heavy gases may collect When siting a head in such places it is most important to ensure that there is no likelihood of flooding by water or excessive dust which may block the sintered disc and prevent gas reaching the sensor When monitoring gases outside those lighter than air will be quickly dispersed but gases heavier than air will tend to form in layers and again cause a dangerous hazard When siting heads outside prevailing winds must be taken into consideration and adequate protection given against wind and rain POISONING OF CATALYTIC SENSORS Catalytic elements used in flammable gas sensors are liable to be rendered inactive due to poisoning by certain groups of compounds In general contact with any gaseous compound capable of producing an involatile residue upon heating is to be avoided Examples of such substances are a Silicon containing vapours as emitted by silicone polishes greases and oils b Petroleum vapours containing tetra ethyl lead or other organo metallic compounds c Phosphoru
20. red in a wide range of enclosures from single module din rail mounting to multi channel interconnected 19 rack based tower systems of unlimited size Each alarm module operates independently having alarm status indicators sounder and three alarm levels with individual relays for the control of remote safety systems 4 20mA or 1 10v outputs are available for use in proportional control systems such as speed control of extractor fans Common alarm relays and indicators are available via an optional facilities module which can be plugged into any available module socket on the system The facilities module can also be used remotely as a control and status indicator panel having built in sounder with sounder accept and alarm reset functions The advanced features designed into the GDS 2010 system ensure ease of maintenance and provide the highest integrity rating with the minimum loss of sensor cover should a fault condition occur COMBUSTIBLE GAS CARD When connected to a suitable power supply and sensor this unit becomes a single channel monitor being fully equipped with 1 Meter indication of gas concentration 2 Power ON indicator 3 Alarm 1 2 and 3 indicators Low High Overrange latched or unlatched energised or de energised option Fault indicator Alarm relays Alarm sounder Analogue output signal 4 20mA optional 1 10v Alarm Accept Reset switch 9 Inhibit switch with indicator to disable Alarm relays 10 System test
21. s in the form of phosphate esters These compounds will permanently affect the detector and if their presence is suspected the response of the detector should be determined by the calibration procedure It is also possible that the reaction of the detector to a flammable gas could be inhibited by halogen containing gases such as chloroform carbon tetra chloride and trichloro ethylene this effect is not permanent Commissioning GAS SENSORS Before applying power to the instrument ensure that all detector heads are connected to the sensor terminals on the printed circuit board fig 3 Red flammable Yellow toxic Blue oxygen Green others Switch on power to the instrument Allow ten minutes for the sensors to stabilise CALIBRATION Establish calibration figures with respect to the L E L limit or the T L V limit of the calibration gas being used See page 13 The following calibration gases are recommended Flammable gases 2 5 methane in air Toxic gases T L V When using this gas ensure adequate ventilation If necessary zero each detector channel in clean air for ambient oxygen monitoring the meter should be adjusted to read 20 8 using the s span potentiometer Apply the calibration gas to the appropriate head at a flow rate of approximately 1 litre per minute When the METER reads a steady value adjust the Calibration Potentiometer to obtain the correct reading for the calibration gas being used
22. switch 11 Zero and calibration adjustments ON OO A TOXIC GAS CARD Similar to the Combustible Gas Card but having the input circuit configured to function with a 4 20mA input from a sensor device Common facilities card optional Is used in multi channel systems to provide alarm outputs which are common to all cards within the same enclosure and may be inserted into any slot within the enclosure The facilities card collects alarm information from all the connected cards and provides common alarm functions as follows Low alarm indicator Low alarm relay High alarm indicator High alarm relay Overrange alarm indicator Overrange alarm relay Fault alarm indicator Fault alarm relay 9 Common alarm sounder 10 Common accept reset switch 11 Power ON indicator ON OA FWD TERMINAL MOTHER BOARD Houses the field terminals for the connection of external equipment i e sensor shut off valves mimic panels etc Also in multi channel systems is used to connect the various alarm and facilities cards together INSTRUMENT ENCLOSURE A standard 19 wide rack houses up to 14 cards various types of enclosure being available to suit the users requirements from single to multiples of 14 ALARM INDICATORS Red L E D s flashing steady when accepted Three levels Low Lo High Hi and Overrange Or adjustable between 5 and 100 F S FAULT ALARM INDICATOR Amber L E D Initiated in the event of a sensor c
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