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Gasmaster (Old Style). - Sure-Safe

1. A A VEC S001 579 10 NS t NI lt L ox ow Sie axe n aa z ME URS HAN 1 dilddv8 43 leje e Q kasa Hyd SISSYHO LE o eb poe L c1 vee 9001 SNS 9001 SNO dX3 00 7 06 094 33825 FINGOW yova 40 3015 1N3NOd l NO PECI YLL SNO 900 3114 0979 I dNI 40 34 1 38IM INdNI 02 7 gt ST NINS3L 9 193130 5315911599 Page 9 Gasmaster Manual modified 071201 doc 7 December 2001 File ref Issue 1 gt CROWCON Crowcon Reference Gasmaster Manual DIAGRAM 3B DETECTING HEAD CONNECTIONS TCgard 82HD vj gv 3395 Se VLL SNS
2. vt 74 579 3M 9001 SNS 02 C 149 l dNI JO 3dAL Page 12 Gasmaster Manual modified 071201 doc 7 December 2001 File ref Issue 1 Gasmaster Manual b CROWCON Crowcon Reference 3 5 ZENER BARRIERS AND GALVANIC ISOLATORS When gas detectors fire detectors are used in a hazardous area an appropriate zener barrier or galvanic isolator as follows is used TXgard Toxic or Oxygen Any shunt zener barrier certified by BASEEFA EExia IIC with an output not exceeding 15 7 and 166mA or the MTL3041 or MTL 5041 galvanic isolator Series 60 Smoke or Heat Any shunt zener barrier certified by BASEEFA EExia IIC with an output not exceeding 28V and 94mA or the MTL3043 or MTL 5061 galvanic isolator TCgard Dual channel zener barrier MTL767 or STLE933 Gaslink Flammable A specially designed barrier interface must be used type Pepperl Fuchs 2731 3 6 INPUT OUTPUT RELAY SETTINGS Gasmaster control units are supplied as standard set as follows Mains input 240V AC Analogue output 4 to 20mA Common low high alarm and fault relays normally energised fail safe Individual channel low and high alarm relays normally de energised Zener earth assumes no zener barriers used These settings can be changed by re positioning links on the printed ci
3. 191 1 Yadav JIN oo N WI SND 3HlM 2 741 SND 3HlM e GU 2 FLI SNS D LNdNl 40 34 1 Page 10 Gasmaster Manual modified 071201 doc 7 December 2001 File ref Issue 1 P CROWCON Crowcon Reference Gasmaster Manual DIAGRAM 3C DETECTING HEAD CONNECTIONS FIRE 9v SN v 3H UN 3Z 9 SND Waviv 3415 971 SAS 3 4 51 m J Y 31 3130 4315 31114 0870 WNvVIV 10 3dAL 11 Gasmaster Manual modified 071201 doc 7 December 2001 File ref Issue 1 P CROWCON Crowcon Reference Gasmaster Manual DIAGRAM 3D DETECTING HEAD CONNECTIONS GASLINK
4. 20v 3 51 1 Gasmaster Manual modified 071201 doc Page 7 7 December 2001 File ref Issue 1 P CROWCON Crowcon Reference Gasmaster Manual DIAGRAM 2 ALARM CONNECTIONS GIF UN TN 5 YANAZ 34 18 Pd IRB MI 58 340 Mv348 30 005 NOOV38 1 9 Page 8 Gasmaster Manual modified 071201 doc 7 December 2001 File ref Issue 1 2 CROWCON Crowcon Reference Gasmaster Manual DIAGRAM 3A DETECTING HEAD CONNECTIONS 96HD DI9 RGD90 TOXIC OXYGEN jeuueg UMA 51 uonbJedo pesn ue 30034313 GHI8 9 6 10 6 10 jndur uo y 400ud INF id 20 19 ALON S 106 10 ONCOR giu 0 0 6 lolo Ww
5. Dog S IN FLAMEPROOF VE B FIRE ALARM TRIPS HIGH MASTER RELAY OPTION NOT USED P B FIRE ALARM TRIPS OPTION NOT USED P CHANNEL RELAY ALWAYS OPERATES RE CARD ELAYS ENERGISED POWER ON FIRE ALARM TRIPS HIGH MASTER RELAY OPTION NOT USED FIRE ALARM TRIPS LOW MASTER RELAY OPTION NOT USED CHANNEL RELAY ALWAYS OPERATES WITH SHORT OPEN FAULT DETECTION File ref Gasmaster Manual modified 071201 doc Issue 1 7 December 2001 Page 28 Gasmaster Manual P CROWCON Crowcon Reference 1 Concentration Display RED 10 Hold Sequence Switch 2 Channel Display GREEN 11 Run Sequence Switch 3 Caption Indicator DISPLAYED UNITS 12 Repeat Fault Alarm Indication CH 1 4 Power Supply Indicator 13 Repeat Low Alarm Indication CH 1 5 OK Indicator 14 Repeat High Alarm Indication CH 1 6 Hold Mode Indicator 15 Write on Pad Gas Identification 7 Run Mode Indicator 16 Repeat Channels Status 8 Test Switch all Control Units Displays 17 Door Lock 9 Alarms and Reset Alarms Switch 18 Link Option Delay Relay Operati
6. 6 55 DIAGRAM 4 INPUT OUTPUT RELAY LINKS TANNY HO NOI 5 0 SNid 1n 983N3 30 55 UJ 983N3 3C 5 999 LNdNI ONIN Page 14 9 D N o 2 o T c o 2 7 9 7 December 2001 Issue 1 Gasmaster Manual b CROWCON Crowcon Reference 4 T ESTING 4 1 INITIAL TESTING Carry 1 out the following with the detectors in normal air With detectors connected to the control unit but with no ancillary equipment connected connect mains or external DC power either 12 or 24V Connect the internal battery connector to the power supply PCB The green power and battery indicators and displays should be on and some alarm lamps may be lit If any fault lamps are lit there is probably a cable fault between the Gasmaster and the detector If there is no cable fault there could be a fault in the detector or zener barrier NOTE The alarm relays for a channel in fault condition are inhibited If any TXgard detectors are supplied with the system the shorting link if fitted must be removed and the system should be left powered overnight to allow the detectors to stabilise The red LED display shows gas concentration In the case of Gasmaster 1 the reading is shown continuously and with Gasmaster 4 the reading fo
7. 0 250 ppm SO1171 Sulphur dioxide 0 10 ppm SO1172 Chlorine ES 0 10 ppm SO1173 Chlorine CTL 0 10 ppm 501182 Nitric oxide 0 25 501174 Nitrogen dioxide 0 10 ppm SO1175 Hydrogen 0 2 v v SO1176 Hydrogen 0 2000 ppm SO1177 Hydrogen chloride 0 10 ppm SO1179 Hydrogen cyanide 0 10 ppm SO1178 Acid gas 0 10 ppm SO1180 Ammonia 0 50 ppm SO1183 Thermal conductivity sensor assembly 96HD TC SO1571 File ref Gasmaster Manual modified 071201 doc Page 30 Issue 1 7 December 2001
8. A fire alarm can be simulated during testing by triggering a smoke detector by smoke or freon aerosol Fire detectors automatically reset when fire symptoms cease 4 3 ANALOGUE OUTPUTS A 12V 4 20mA output or 1 5V output is available from each channel maximum total loop resistance 150 ohms Calibration of these outputs with test gas should be carried out when they are used rather than the control unit display If using the analogue outputs it may be preferable to calibrate the system to these rather than the control unit display as the resolution of the outputs is better than the display File ref Issue 1 Gasmaster Manual modified 071201 doc Page 16 7 December 2001 Gasmaster Manual b CROWCON Crowcon Reference 5 CALIBRATION CHECKING 5 1 CROWCON GAs TEST KITS The operation of Crowcon gas detection systems is easily checked by means of gas test kits The basic kit consists of a fine control valve flow indicator hose and adaptor with full instructions The valve fits our standard 20 litre gas cans which can be supplied containing standard mixtures suited to our various models see table The flow indicator ensures that gas is not wasted during the test procedure Properly used a 20 litre can will last for 30 45 minutes enough for many tests Crowcon also supply a pressure gauge to check the contents of the gas can Other mixtures are available to special order Gas Mixture Detectors Suitable For 1 25 and 2 5 metha
9. Fuse 20mm 2A Q B 22 4 20mA 37 Remote Accept Reset Terminals Input Card Explosive Input Card Fire 8 External Sounder Beacon Fuse 20mm 1 23 Card ALL GASES F4 9 High Alarm LED FIRE 10 Low Alarm LED FIRE 11 12 13 14 15 External DC Battery Sounder Beacon 30 Zero Preset ZERO e Channel 4 Position shown spare Terminals m LJJa EE y ur hhi O Ld fi POSITION FOR ZENER BARRIER DETECTING TO WHEN IRE CHANNELS URTH CHANNEL
10. cable with 1mm conductors 96HD DI9 Gaslink Gaslink Toxic TXgard TCgard Fire DI5 6 Flammable Oxygen Oxygen Detectors 81HD 73HT Maximum 370m 18m IIC 1100m 700m 290m 2900m length 146m IIB Maximum 12 50hms 3 8ohms with 390ohms with 24ohms with 10ohms 100ohms loop zener barrier zener barrier zener barrier with zener with zener resistance type 2731 type MTL 728 type MTL 715 barrier barrier otherwise otherwise otherwise 730ohms 180ohms 165ohms NOTE Wiring continuity tests must be carried out with detecting heads disconnected 3 3 EARTHING Intrinsic safety earthing must be used as required Because of the low signal levels generated by gas detectors it is usually necessary to avoid all risk of interference to connect the screen of the cable to the earth plate of the detector head long reach glands and or the screen terminals should be used Earth loops must avoided so earthing is done through the zener barrier or the normal safety earth of the system The zener earth link on the power supply alarm PCB in the control unit must be correctly set see diagram 4 File ref Gasmaster Manual modified 071201 doc Page 5 Issue 1 7 December 2001 Gasmaster Manual b CROWCON Crowcon Reference 3 4 ELECTRICAL CONNECTIONS REFER DIAGRANS 1 TO 3 Connections are shown by numbered screw terminal blocks diagram on the rear of the front door is also provided to assist in installation a Terminals at the top o
11. 0 1 or 2 providing a zener barrier is connected between them and the control unit f Environmental Sampling Unit 87 ESU This has been designed primarily to monitor heavy gases such as chlorine or propane LPG which because of their nature flow to low points and do not diffuse readily in the general atmosphere The equipment comprises a sampling chamber an explosion proof electric fan and collecting pipes The 12v fan is approved EExm IIC T4 which allows the ESU to be used in hazardous areas zones 1 and 2 gas groups IIA IIB IIC A Gasmaster input alarm card type ESU supplies a fused 12v to drive the 87 ESU and includes fan failure alarm sensing with relay outputs File ref Gasmaster Manual modified 071201 doc Page 3 Issue 1 7 December 2001 Gasmaster Manual b CROWCON Crowcon Reference 2 SITING OF DETECTORS 2 1 GAS DETECTORS SEE SECTION 7 FOR MORE INFORMATION In siting remote gas detectors each case must be considered individually and Crowcon will provide any necessary advice and assistance also refer to BS6959 1988 In general for gases lighter than air the detectors should be above the area where leaks are likely and for gases heavier than air the detectors must be at floor level or in inspection pits or ducts into which heavy gas may flow However not all cases are as simple For example if carbon monoxide which is only slightly lighter than air is under pressure and is suddenly released into the atmospher
12. 5 litre per minute Flow the gas for one minute and adjust the Cal control on the head amplifier in the detector junction box until a reading of 200mV is obtained at the test point for gas at full scale concentration or 120mV for gas at half scale concentration Adjust the Cal control on the input alarm card to obtain the appropriate reading on the display TXgard OX Detector Connect a digital meter to the test point on the head amplifier in the detector junction box Remove the red sensor lead from the terminal block and set the zero control to give a reading of 40mV Adjust the zero control on the alarm card to give a zero reading on the display Reconnect the red lead and allow 5 minutes for the sensor to settle Adjust the Cal control on the head amplifier in the detector junction box to read 175mV in normal air Adjust the Cal control on the input alarm card to obtain a reading of 20 8 on the control display d Gaslink See separate instructions supplied with detector e Environmental Sampling Unit 87 ESU Switch on power alarms may be on reset by pressing reset accept button on front panel SLOW LED indicates low voltage or fan obstruction Channel and low master relay will operate Master relay can be accepted by front panel accept reset switch STOP LED indicates fan blades obstructed or fallen off Channel and high master relay will operate Master relay can be accepted by front panel accept reset swi
13. Gasmaster Manual b CROWCON Crowcon Reference Table of Contents T INSTALLATION I QS aun a E O E 2 1 1 CONTROL UN 2 1 2 DETECTING HEADS LEER 3 2 SEPING OF DETECTORS er 4 2 1 GAS DETECTORS SEE SECTION 7 FOR MORE INFORMATION 4 2 2 FIRE DETECTORS etre esI Dee 4 MAT ormm 5 3 1 C ABEBALYPESG AS 5 3 2 CABLE LENGTH nu 3 3 EARTHING SSL d i 3 4 ELECTRICAL CONNECTIONS REFER TO DIAGRAMS TO 3 2 6 3 5 ZENER BARRIERS AND GALVANIC 5 5 13 3 6 INPUT OUTPUI REEAY 65255 u cete ete doses ee q 13 As 15 4 1 TNTPPFATSOPESTING Z teet NS 15 4 2 ALARM RELAY OPERATION 606550535 16 4 3 ANALOGUE OUTPUTS ronse 16 5 CALIBRATION CHECKING 17 5 1 CROWGON GASZEESTIKTPSiuu 17 3 2 CATIBRATIONANDJUSTMENT Lu t e CE Q No ERR ERE 17 6 SERVICE sesenta terio oem a
14. TXgard IS Formerly RGD90 Toxic and Oxygen Detectors Most of this range of detectors are intrinsically safe and can be used in hazardous areas Zones 0 1 and 2 Gas Groups IIB IIC providing there is a zener barrier between them and the control unit A zener barrier is not necessary if the detector is in a non hazardous area NOTE The TXgard range includes carbon monoxide hydrogen sulphide chlorine sulphur dioxide acid gas nitric oxide nitrogen dioxide hydrogen hydrogen cyanide and ammonia versions c TCgard Thermal Conductivity Detectors These detectors operate on three wires and are intrinsically safe when connected through the specified zener barrier allowing them to be installed in hazardous areas Zones 0 1 or 2 The detectors use the thermal conductivity principle to monitor the percentage by volume level of a range of gases including methane hydrogen carbon dioxide helium and halon in air or binary mixtures of these gases d Gaslink Flammable and Toxic Oxygen Detectors Gaslink is an obsolete intrinsically safe range of detectors providing a 4 20mA output and having a built in LCD display Flammable versions are three wire operation and require two zener barriers whilst the toxic gas and oxygen versions operate in the same way as RGD90 toxic oxygen e Smoke and Heat Detectors Fire detectors may be supplied in standard or intrinsically safe form The latter can be located in a hazardous area Zones
15. acons operate This condition can be accepted by pushing the Accept Reset switch which silences the internal and external sounders but the Yodalight beacon remains on and resets the master low level alarm relay but channel relays remain in the alarm state The master low alarm relay will change to the alarm state again if another channel detects gas above the low alarm level If the gas concentration increases above the high alarm level the relevant channel high level alarm LED illuminates the channel high alarm relay changes and the internal sounder is heard In addition the master high alarm relay changes Yodalight sounders and beacons will also operate The high alarm state can be accepted as in b above when sounders are silenced and master alarm relays reset The master high alarm relay will change to the alarm state again if another channel detects gas above the high alarm level It is recommended that alarm sounders etc which are required to be silenced on accepting an alarm state are connected through the master relays Any equipment which needs to remain operational after accepting an alarm should be controlled by the channel relays which can be connected in series or parallel as required When gas is no longer present pressing the Accept Reset switch resets all alarms and relays In the case of fire detection the indicators and alarm relays have similar functions except that there is only one alarm level for each zone
16. and replace any faulty parts free of charge providing that the equipment has not been misused 6 2 COMMISSIONING AND SERVICE Crowcon strongly recommend that fixed gas detecting installations are commissioned Commissioning includes carrying out a full check of the equipment and its wiring as well as calibration and operation checks on all detectors Our Service Department will also be pleased to advise on regular service and maintenance requirements and we can offer annual maintenance agreements Similar arrangements can be made by our sales and service distributors outside the United Kingdom 6 3 SENSOR REPLACEMENT Pellistor sensors used in 96HD 81HD 73HT DI5 6 DI9 detectors and thermal conductivity sensors do not have a wear out mechanism However pellistors can be poisoned and then require replacement because of reduced sensitivity Pellistors can be changed on site although some difficulty may be encountered in undoing the sensor head Electrochemical sensors used in toxic gas detectors need replacing about every two years while oxygen cells have a life of one year Crowcon supply the replacement cells and removal and refitting is easily accomplished Crowcon operate a factory detector repair scheme 6 4 SETTING DETECTORS a 96HD 019 DI5 6 and 81HD Detectors Check from the equipment specification which type of pellistor is used The standard VQ21T sensor should give 2 05V at terminal 1 black and 3 red in the detector ju
17. e a drop in temperature is caused resulting in an increase in density This may cause the gas to fall to floor level Also the nearer in density to air a gas is the more easily it will flow with air due to draughts ventilation etc Therefore a compromise with gases like carbon monoxide and also gases only slightly heavier than air such as hydrogen sulphide and nitric oxide is to mount the detectors at a height as close as possible to the breathing area of personnel being protected When monitoring deficiency of oxygen which is slightly heavier than air it is necessary to consider what might be displacing it For example carbon dioxide which is heavier than air will sink to floor level so this is where the detectors should be Conversely if helium is displacing the oxygen the detectors should be mounted at a high level On the other hand if combustion is consuming oxygen the whole volume of air would gradually become depleted in oxygen and detector location would not be so critical When installing gas detectors it is advisable to ensure that the gas inlet is not exposed to liquid or dust contamination for example by positioning the unit downwards splash deflectors should be used when water or other liquid is continually present 2 2 DETECTORS The location of smoke and heat detectors is usually governed by local Codes of Practice such as BS5839 Part 1 or regulations In general smoke detectors can be mo
18. e the lid is open access to the lower set of PCBs is made by gently hinging the main display board to one side The board can be unclipped from both brackets if required but it is simpler to leave one bracket attached and use this bracket as a hinge The system can now be tested and calibrated in accordance with Sections 4 and 5 File ref Gasmaster Manual modified 071201 doc Page 26 Issue 1 7 December 2001 Gasmaster Manual CROWCON Crowcon Reference 8 3 FIXING DIMENSIONS T 90mm 15mm 200 4 HOLES _ CABLE ENTRIES 210mm E Em amp no Y RAR d a 1 AN gt File Gasmaster Manual modified 071201 doc Page 27 Issue 1 7 December 2001 Gasmaster Manual 9 INTERNAL AND PANEL LAYOUT CROWCON Crowcon Reference 1 Standby Battery Sealed Lead Acid 16 Earth Chassis Stud 31 Pellistor Voltage Preset Head Volts 2 Write On Pad Gas Fire Detector Location 3 Write On Calibrated Range Of Detector 4 Internal Sounder 19 High Alarm Set Point Terminals 5 Mains Fuse 20mm 250mAA S F1 20 Low Alarm Set Point 6 Sensor Type Fitted 7 Battery
19. ed back in so that the display is always the right way up irrespective of the orientation of the enclosure The circuitry which controls four push buttons for TEST RESET HOLD and RUN functions is also located on the main display PCB With the lid of the enclosure in place plungers from the lid mounted buttons break an infra red beam when they are pushed With the lid removed small PCB mounted push buttons beside the infra red sensors can be used for testing purposes or the beam can be broken using a pencil or similar opaque object A connector on the PCB allows for remote switches to be fitted for OEM installations See page 24 8 2 TESTING AND CALIBRATION Only basic system testing can be performed with the lid in place 1 Lamp operation can be checked by pressing the TEST button and viewing the sub display board through the window 2 Apply test gas to the detecting heads or simulate a fire smoke condition to check the operation of the measuring and alarm circuits and the RESET button 3 The HOLD and RUN buttons can be used to check the cyclic operation of the LED digital displays To perform full test and calibration procedures as described in Sections 4 and 5 it will be necessary to open or remove the lid of the flameproof enclosure As stated before the flameproof Gasmaster must be completely de energised before the lid is opened and a permit must be obtained before an open system can be re energised in a hazardous area Onc
20. ee E eure deo en PEU ta eise s abe eaae deo E ura ean Thai E PR EAR Ee RS 18 6 1 WARRANTY intei IUE ERR 18 6 2 COMMISSIONING AND SERVICE 5 18 6 3 SENSOR REPLACEMENT 9 6 4 SETTING DETEGTORS eee ahe 7 GAS DETECTOR INSTRUCTIONS 7 1 DI9 DI5 6 AND 81HD FLAMMABLE GAS DETECTORS 7 2 RGD90 TOXIC GAS AND OXYGEN DETECTORS 7 3 RGD90 THERMAL CONDUCTIVITY GAS 22 8 FLAMEPROOF GASMASTERS 24400055000 106 6 u ark no Qa quq qaku uq sss 25 8 1 DESCRIPTION 33 535 a k Det Pr 8 2 TESTING AND CALIBRATION 8 3 PEXING DIMENSIONS Zn esee e ie bte en 9 INTERNAL AND LAYOUT Fo eua Cue Einb aede pe ene e eR ek ER a 28 10 SPARE PARTS LIST Moe 30 File ref Gasmaster Manual modified 071201 doc Page 1 Issue 1 7 December 2001 Gasmaster Manual CROWCON Crowcon Reference 1 INSTALLATION Crowcon gas detection systems are fully tested and calibrated before they leave the factory However after installation we strongly recommend that full testing and commissioning is carried out This is best done by Crowco
21. f the case are for relay connections whilst terminals at the bottom are for mains input external DC input external battery detecting heads analogue drive and alarm units b Output Helays are DPCO and are isolated from the system power supply and are rated at 240V AC 5A C Detectors are set up at the factory with their own input alarm card and it is essential that detectors and input alarm cards are matched Therefore detector 1 must be connected to input alarm card 1 detector 2 must be connected to input alarm card 2 etc NOTE TXgard detectors may or may not have shorting links fitted between the blue and green sensor leads which should be removed just before commissioning File ref Gasmaster Manual modified 071201 doc Page 6 Issue 1 7 December 2001 Crowcon Reference CROWCON DIAGRAM 1 ELECTRICAL CONNECTIONS Gasmaster Manual Ina p NS ff uw 9 193130 Ov3H 9 193130 2 OY3H 9 193130 OY3H 9N1123130 l rez rez rez rez 9 aje z o e v 3503 S V HNNV H TANNVHO 6 TINNVHO TANNVHO ON NO ATIVE NO 3N3 3d 5109100 gt gt
22. in that the pellistors and sinter assembly may be replaced Since the unit is certified flameproof this work should only be carried out by Crowcon or one of their approved Service Agents Replacement of the sinter may be required if it has become blocked with dust or oil which causes the response to test gas to be slow and the sensitivity impaired The 019 is fully encapsulated and is therefore non repairable Recalibration Detectors should be checked with a test gas at least 6 monthly The test gas should be applied using either the calibration adaptor or through the spigot of a weatherproof cap The flow rate of the test gas should be 0 5 litres per minute Crowcon s gas test kits are a convenient way of providing test gas Accessories DI5 6 or 018 DI9 81HD or 82HD Calibration cap CO1501 CO1501 Remote calibration adaptor CO1300 Spray deflector weatherproof cap 4253 1052 Flow adaptor CO1502 CO1057 Collector cone CO1503 CO1051 Carbon filter CO1254 CO1254 Swivel mounting bracket CO1340 CO1340 96HD 019 DI5 6 81HD CONNECTION DIAGRAM IK is the usual resistor fitted to 81HD 27R being only for 73GW 74GW or 72FP systems this version is called 81HD LR YELLOW _ Only for FA 81HD RED t 73 S 1K SENSOR gt 27R c BLUE OR GREEN 2 REFERENCE BLACK gt File ref Gasmaster Manual modified 071201 doc Page 21 Issue 1 7 December 2001 Gasmaster Manual b CROWCON C
23. n The calibration of the detecting head can be checked by passing a sample of the span gas into the sensor at a flow rate of 100ml min inaccuracies calibration setting can corrected by adjusting the Cal pre set on the amplifier to make the DVM read 200mV If the control equipment display needs adjusting the relevant procedure is covered in the operating manual for that equipment Sensor Care should be taken to prevent water or water droplets from entering the sensor and the sensor must not be connected to a high pressure gas source Sensor Replacement Make sure the power to the unit is off Disconnect the three sensor wires from the terminal block inside the junction box and unscrew the whole sensor housing from the junction box Fit a new sensor assembly Replace the leads observing the colour code Remove amplifier fixing screws and rear lid to gain access to electronics and BAL pre set VR3 Connect DVM between the red and orange terminals switch on power and adjust BAL pre set to make the DVM read zero mV Re assemble amplifier allow 1 2 hours for detector to stabilise then zero and calibrate see Setting Up instructions 8 FLAMEPROOF GASMASTERS 8 1 DESCRIPTION The Flameproof Gasmaster GMS FP offers the same facilities as the standard Gasmaster but instead of being packaged in a slim wall mounted box is mounted in a cast aluminium or iron flameproof enclosure The flameproof Gasmaster is certified t
24. n s Service Department or by one of our distributors whose engineers have been trained by us Rectification of installation faults can be an expensive exercise 1 1 CoNTROL UNIT The Gasmaster control unit is designed for wall mounting in any convenient non hazardous location where a suitable power supply is available Gasmaster control units can be powered from 110V or 240V AC and 12 or 24V DC Dimensions and fixing information are given below Special mounting instructions apply for flameproof models see Section 7 4 Holes e6mm 420mm 324mm j l 4 Holes m 26mm To prevent dust and water ingress all cable entries and knock outs must be checked and sealed if necessary File ref Gasmaster Manual modified 071201 doc Page 2 Issue 1 7 December 2001 Gasmaster Manual b CROWCON Crowcon Reference 1 2 DETECTING HEADS a Flammable 96HD 019 DI5 6 81HD and high temperature version 73HT and Thermal Conductivity TCgard Detectors These detectors are flameproof and can be installed in a hazardous area Zones 1 and 2 Normally they are supplied complete with a metal junction box and 96HT is supplied with 300mm of mineral insulated cable fitted with a 20mm threaded gland to enable the detector to be mounted in a hot compartment Note that 96HD is the detector usually supplied with Gasmaster 81HD DI9 having been b
25. nction box The voltage must be checked at the detector not at the control unit Adjustment is done by means of the Head Volts control on the input alarm card Apply calibration gas e g 2 5 methane in air which is 50 LEL to the detector at a rate of no more than 0 5 litre per minute Adjust the Cal control on the input alarm card to give the correct reading Check with Crowcon for other types of pellistor b TXgard and TCgard Detectors File ref Gasmaster Manual modified 071201 doc Page 18 Issue 1 7 December 2001 Gasmaster Manual b CROWCON Crowcon Reference The electrochemical sensors in RGD90 detectors polarise if the system is not operating e g during mains failure if there is no standby battery This causes a delay in obtaining a stable output when the sensor is operational again If a detector is to be out of commission a shorting link should be connected between the blue and green sensor leads in order to prevent polarisation To set the zero of an RGD90 detector a digital meter which must be intrinsically safe if the area is hazardous is first connected to the test point on the head amplifier in the detector junction box In normal air the reading should be 40mV and the head amplifier zero control should be adjusted to give this reading The zero control on the input alarm card should now be set to give a zero reading on the display Apply calibration gas to the detector at a rate of no more than 0
26. ne in air 81HD 73HT DI9 DI5 6 0 75 pentane in air 81HD 73HT DI9 DI5 6 200 ppm carbon monoxide in air RGD90 CO 25 ppm 5 ppm hydrogen sulphide in air RGD90 HS 10 ppm sulphur dioxide in air RGD90 SO Freon aerosol Series 60 Smoke Detectors NOTE Gas mixtures supplied in 20 litre cans are usually not as precise in concentration as the mixtures used for factory calibration and they deteriorate with age 5 2 CALIBRATION ADJUSTMENT Gasmaster systems are supplied factory calibrated and there is no need for re calibration on commissioning although functional testing is a good idea using the gas test kits After 6 months service re calibration is recommended Each alarm module has a Cal control for setting calibration while the detector is sensing gas of known concentration Great care is needed during this procedure and it is recommended that Crowcon engineers or other experienced personnel carry it out Crowcon s range of detectors includes models for chlorine nitrogen dioxide and nitric oxide Because of the nature of these gases special methods of calibration have to be employed File ref Gasmaster Manual modified 071201 doc Page 17 Issue 1 7 December 2001 Gasmaster Manual b CROWCON Crowcon Reference 6 SERVICE 6 1 WARRANTY Crowcon products are designed to give years of trouble free life and our normal guarantee is one year In the unlikely event of one of our systems failing within one year we will repair
27. o EExd IIB T6 so can be mounted in Zones 1 or 2 Access to the internal printed circuit boards of the flameproof Gasmaster is by removing the twelve lid retaining bolts and swinging the lid open on its hinges The lid can be lifted of its hinges if required The flameproof Gasmaster must be completely de energised before the lid is opened Sufficient threaded cable entries are provided it is important to install flameproof cable glands to maintain the integrity of the flameproof certification File ref Gasmaster Manual modified 071201 doc Page 25 Issue 1 7 December 2001 Gasmaster Manual b CROWCON Crowcon Reference The flameproof Gasmaster uses the same power supply alarm cards and input cards as the standard Gasmaster with the following modifications 1 A back up battery is not connected to the power supply 2 The fire smoke alarm card has a zener barrier mounted directly on the PCB and the alarm relays are normally energised see page 23 for the electrical connections and link options 3 On initial switch on the alarm relays are automatically inhibited for five seconds allowing the detecting heads to settle down The display PCB has been specially configured for use in flameproof enclosures with all of the status LEDs channel indicators and digital readouts clustered together on a small sub display card This sub display card can be unplugged from the main display PCB and rotated through 90 180 270 then plugg
28. on at Power On FLAMEPROOF VERSION g J ma INHIB PARK FLAMEPROOF 4 510 RELAY INHIBIT INHIBIT CENTRE PIN INHIBIT NO INHIBIT CENTRE PIN PARK P TEST N J M OPTIONAL REMOTE PUSH BUTTON CONTROLS File ref Gasmaster Manual modified 071201 doc Issue 1 7 December 2001 Page 29 Gasmaster Manual b CROWCON Crowcon Reference 10 SPARE PARTS LIST CONTROL UNIT CROWCON STOCK NO Power supply GMS 1000 SO1149 Alarm card GMS 1001 SO1151 Exp input card GMS 1005 SO1153 4 20 Input card 2 wire GMS 1006 SO1152 4 20 Input card 3 wire SO1273 Fire input card no zener SO1218 Fire input card with zener SO1217 Display GMS 1 GMS 1003 SO1159 Display GMS 4 GMS 1002 SO1150 Display GMS FP SO1126 Sub display GMS FP SO1215 Ribbon cable assembly GMS 1 SO1208 Ribbon cable assembly GMS 4 SO1207 Fuse F1 EO1222 Fuse F2 EO1060 Fuse F3 EO1060 Fuse F4 EO1223 Fuse ESU input card GMS 2025 EO1307 Jumper links EO7109 Spare key MO2090 Battery 0 8AHr EO1009 Transformer EO1212 Service Manual MO7068 DETECTING HEADS TXgard Range Head amplifier IS toxic TXgard IS 501225 Head amplifier 15 oxygen TXgard IS OX SO1226 Head amplifier thermal conductivity TCgard SO1274 Sensors Oxygen 0 25 v v SO1169 Hydrogen sulphide 0 25 ppm SO1170 Carbon monoxide
29. pe Adopt a similar procedure but set zero with the red sensor lead removed from the terminal block Replace the lead and wait for 5 minutes before adjusting the Cal control to give 175mV at the test point in normal air Replacement of Sensors Because the various sensors have different outputs a header matched to each sensor which is plugged into the amplifier PCB is used to provide sensor to amplifier compatibility TXgard OX uses a different amplifier Toxic gas sensors have a two to three year life At the end of their life they are replaced by a complete sensor assembly This consists of the sensor in its housing and a new header Use of the new header ensures compatibility between a new sensor and the amplifier in case the sensor specification has changed Oxygen sensors last for one year and again the whole sensor assembly is replaced Care must be taken that the shorting link sleeve is not removed from the toxic gas sensors until 30 minutes before they are installed in their detecting head and connected to the amplifier If this is not adhered to polarisation of the sensor occurs and the detector must then be left overnight before re calibration of the detector is attempted Nitric oxide hydrogen chloride and ammonia sensors do not have shorting link sleeves File ref Gasmaster Manual modified 071201 doc Page 22 Issue 1 7 December 2001 Gasmaster Manual CROWCON Crowcon Reference Fitting Instructions for Replacemen
30. r each channel is shown in turn for 5 seconds when in the Run mode The reading for each channel can be selected manually by means of the Hold push switch The green display shows the scale of the gas concentration reading in parts per million of the Lower Explosive Limit or volume depending on the gas being monitored Press Run until the green display indicates C1 Channel 1 then press Hold If the reading is not zero adjust the Zero control for that channel Press Run again to select C2 and set zero Continue for all channels being used NOTE If the system has any oxygen detectors set the reading to 20 996 when the oxygen channels are selected using the Cal control Do not attempt to zero oxygen channels in air Fire detector channels give no meter reading and have a non adjustable alarm point With all channels zeroed or set to 20 9 for oxygen detectors press the Accept Reset Switch on the front panel when all alarm indicators should go out The Low Level alarm and High Level alarm levels are normally factory set but they can be checked or reset Select the channel to be tested and slowly rotate its zero control clockwise At a pre set level of gas concentration the low level indicator and the audible alarm in the Gasmaster will operate The audible alarm can be cancelled by the Accept Reset switch continue turning and the high level indicator will operate The readings at which alarm
31. rate on the thermal conductivity principle The sensing element is exposed to the gas and the reference element is sealed off in a reference gas air in a separate chamber The out of balance signal generated by the concentration of gas is amplified and converted into a 4 20mA signal Electrical Connections A 6 way terminal block provides all of the connections to the TCgard detecting head The lower three terminals marked orange red blue are internally connected to the thermal conductivity sensor the upper three terminals marked and signal are connected to the control equipment GASMASTER TERMINALS TCgard 2 2 3 not used 4 Setting Up Allow detecting head to stabilise for 1 2 hours after powering up before any attempt is made to calibrate or zero Connect a DVM to the test points on the amplifier in the junction box Zero should give a reading of 40mV and lull scale should give a reading of 200mV Zero The zero should be re checked by passing a sample of the background gas into the sensor at a flow rate of 100ml min Check the amplifier label for details of the background gas normally air but possibly nitrogen carbon dioxide and argon Any inaccuracies in zero setting can be corrected by adjusting the zero pre set on the amplifier to make the DVM read 40mV File ref Gasmaster Manual modified 071201 doc Page 24 Issue 1 7 December 2001 Gasmaster Manual b CROWCON Crowcon Reference Calibratio
32. rcuit boards as shown in Diagram 4 File ref Gasmaster Manual modified 071201 doc Page 13 Issue 1 7 December 2001 gt CROWCON Crowcon Reference Gasmaster Manual AL df 544 02 138 YOLOANNOD A NY 3AOB8V N 045 38 150 OV OLL 403 39805 404 IJANS 14 3504 SNIV 1934409 JHL 330 03H01 JHL HIM J 38 AINO 02 YANYOASNVUYL JHL 40 NOILISOd JHL US 72062 157 9 ooj OO Lt 9 aon 3 55 0 4 looo 4 OOO 331N39 9 NITIV4 9 5 4 381N35 Id 34130 3 3MIN 33 0351903 3 134 TANNY J 381N39 035 3 AV 1321 TNNYHO OOD 000 d 441549 q3sn SJY 33N3Z 4 Z OL Nid 3HIN3O YINIZ 7000 S OOOO O p e 45 T NTT 193135 39v Q Nid JHIN39 035 9395
33. rowcon Reference 7 2 TXGARD Toxic GAs AND OXYGEN DETECTORS These detectors employ electrochemical sensors installed in a junction box which contains an amplifier transmitter to provide a 2 wire 4 20mA output sink not source They can be used in hazardous areas in conjunction with a suitable zener safety barrier For operation an input of 7 0 to 32V DC is required terminal 3 positive Maximum cable loop resistance is 180 ohms Most TXgard detectors can be mounted in any orientation but attention must be paid to the physical characteristics of the gas being measured density etc Exceptions to this are acid gas HX detectors They must be installed with the sensor pointing down at 45 If a liquid blob appears on the membrane of the HX type do not remove it Notes Electrochemical sensors need to be operating under powered conditions for a few hours before calibrating or zeroing Pay particular attention to this when commissioning systems with nitric oxide NO hydrogen chloride HCL and ammonia NH3 detectors Calibration and Zeroing Connect a DVM to the test points on the amplifier in the junction box Adjust the zero control to give 40mV at the test points in clean air Apply calibration gas at no more than 0 5 litre min using a Crowcon gas test kit or similar Flow the gas for one minute and adjust the Cal control to obtain 120mV for half full scale gas at the test points Calibration and Zeroing TXgard OX oxygen ty
34. s are triggered can be checked or if necessary reset using the Set L or Set H controls The best way to do this is to turn the Set L and Set H controls fully clockwise Set the level on the display at which the low level alarm is to operate using the Zero control Then slowly turn the Set L control anti clockwise until the alarm indicator lights Repeat with the high alarm level using Set H Reset the zeros after this procedure by turning the Zero controls anti clockwise When satisfactory operation of the system has been proved connect any external equipment and check its operation File ref Issue 1 Gasmaster Manual modified 071201 doc Page 15 7 December 2001 Gasmaster Manual b CROWCON Crowcon Reference NOTE In mains fail conditions the Power indicator flashes on and off twice per second The Lamp Test push switch checks the internal audible alarm and indicators For safety reasons it does not activate alarm or fault relays or Yodalights connected to the sounder beacon terminals Press Run for normal operation of Gasmaster 4 4 2 ALARM RELAY OPERATION a b If gas above the low alarm level is detected the low level alarm LED for the relevant channel illuminates the channel low alarm relay changes and the internal sounder is heard In addition the master low alarm relay changes and if one or two Yodalights are connected to the sounder beacon output terminals their sounders and be
35. t Sensors 1 Make sure power to unit is off 2 Disconnect the two or three sensor wires and unscrew the whole sensor housing from the junction box 3 Remove amplifier lid and remove amplifier from junction box Change the plug in header ensuring notch in header matches notch in mounting 4 Fit a new sensor assembly Replace the leads observing the colour code 5 Allow a few hours for the detector to stabilise then zero and calibrate ELECTRICAL CONNECTIONS RGD90 DETECTING HEAD m HEAD AMPLIFIER SCREEN TERMINAL Table showing RCD90 GREEN RED File Gasmaster Manual modified 071201 doc Page 23 Issue 1 7 December 2001 Gasmaster Manual b CROWCON Crowcon Reference 7 3 THERMAL CONDUCTIVITY GAS DETECTOR The TCgard is a thermal conductivity gas detector suitable for measuring flammable gases in percentage levels as well as certain non flammable gases and binary gas mixtures This relies on there being a substantial difference between the thermal conductivity of the two gases being measured The thermal conductivity sensor is screwed into a plastic junction box which contains an amplifier transmitter providing a three wire output 2 wire power and 1 wire signal 4 20mA sink with shared OV The sensor consists of two matched elements which ope
36. tch FAULT LED indicates blown fuse on input card This must be replaced by the same type due to certification requirements for this unit to be used in a hazardous area see spare parts list The Gasmaster meter display for this channel will only indicate zero 0 File ref Gasmaster Manual modified 071201 doc Page 19 Issue 1 7 December 2001 Gasmaster Manual b CROWCON Crowcon Reference 7 GAS DETECTOR INSTRUCTIONS 7 1 96HD DI9 015 6 AND 81HD FLAMMABLE GAS DETECTORS These gas detectors are designed for the detection of flammable gases up to the lower explosive limit LEL They are flameproof and must be used with a suitably approved junction box and cabling Principle of Operation The detectors use catalytic pellistor sensors These consist of two elements one of which is the sensor and the other the reference They are connected in two arms of a Wheatstone Bridge and are maintained at about 500 C In the presence of a flammable gas combustion occurs on the catalytic surface of the sensor and the heat of reaction increases its temperature This increases the resistance of the element which unbalances the bridge Siting Detectors should be located where concentrations of flammable gas are most likely to a Detectors should be mounted close to the floor for heavier than air gases such as butane or propane and near to the roof to detect lighter than air gases such as methane or hydrogen b Heavy gases are likel
37. unted up to 15m high and cover a maximum area of 100m and heat detectors should be no more than 9m high and cover an area no more than 50m Escape routes should have more than the minimum number of detectors Normally 20 detectors per zone is considered a maximum Each Gasmaster fire channel will operate one fire zone File ref Gasmaster Manual modified 071201 doc Page 4 Issue 1 7 December 2001 Gasmaster Manual b CROWCON Crowcon Reference 3 WIRING Because of the low signal levels carried by wiring between gas detectors and their control unit it is essential not to run cabling near high power electrical equipment 3 1 CABLE TYPES Flammable 96HD 019 DI5 6 81HD and 73HT and thermal conductivity TCgard detectors require 4 core cable These detectors are flameproof and in hazardous areas must be wired in mineral insulated e g BICC 4L1 or steel wire armoured e g BICC 6944 with suitable glands and accessories TXgard toxic and oxygen detectors are two wire devices whereas TCgard is a three wire device Because they are intrinsically safe rather than flameproof it is not essential to use flameproof cable but it is to be recommended for mechanical protection Screening is also usually necessary Fireproof cable e g Pirelli FP200 is often used for these detectors and is also suitable for fire detectors 3 2 CABLE LENGTH The maximum loop resistance depends on the detector type and the following data assumes the use of
38. y to accumulate in sumps and trenches whilst light gases will rise into the apex of a roof Valves flanges and compressor bearing seals are potential sources of leakage d Detectors should be positioned pointing vertically downward and be protected with a weatherproof cap spray deflector if there is a risk of water spray or dust e Detectors will lose sensitivity if located in an area where catalyst poisons such as silicones lead organics chlorine or sulphur compounds are likely to be present f Sensitivity and balance of the Wheatstone Bridge may also be affected by long term exposure to levels of flammable gases above the upper explosive limit UEL Electrical Detectors are supplied with three or four leads for connection as shown It is important that the correct voltage is applied to the detector which will depend on the type of pellistor fitted PELLISTOR TYPE BRIDGE VOLTAGE POWER W OR VQ2 OR 2OON 0 36 1 1 resists lead VQ16 1 1 poison resisting VQ21T 0 75 poison resisting VQ22 0 36 poison resisting VQ25 2 0 0 75 resists chlorine but not suitable for methane The voltage must be measured in the junction box between the red and black leads and should be accurate to 0 1V Mechanical File ref Gasmaster Manual modified 071201 doc Page 20 Issue 1 7 December 2001 Gasmaster Manual b CROWCON Crowcon Reference 96HD DI5 6 and 81HD detectors are repairable

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