Crowcon TXgard Plus Fixed Gas Detector User Manual DOWNLOAD
Contents
1. REAR VIEW OF AMPLIFIER W CROWCON GAS RANGE booooo N Y 62 CEE y 2 RELAY CONTACT CONTACT m ALARM 2 a ALARM 1 LINK FAULT USED FOR ALARM OXYGEN TXGARD SETIPOTS FOR TOXIC LINK SET TO OTHER CONTROL EQUIPMENT TO 96HD SENSOR INTERNAL TERMINAL LAYOUT ALARM RELAY VERSION ONLY Diagram 2 Terminal and amplifier layouts WCROWCON 4 Detecting Gas Saving Lives TXgard Plus Detector configuration 2 Detector configuration 2 1 Standard configuration As standard TXgard Plus is factory set as follows Current source with Fault 2 mA Inhibit ie Zero Cal mode 4 20 mA Normal operation 24 mA Over range clamp AL1 relay Alarm level 1 see Table 3 Normally de energised energising on alarm Contact normally open NO closing on alarm AL2 relay Alarm level 2 see Table 3 Normally de energised energising on alarm Contact normally open NO closing on alarm FAULT relay Normally energised de energised on fault Contact normally closed NC opening on fault Alarm fault relays automatically reset when alarm or fault has cleared INHIBIT Normally selected ie when CAL ZERO selected current output is forced to 2mA and relays are held in normal no alarm state2. will typically allow cable runs up to 2000m Table 4 shows maximum cable distances given typical cable parameters 8 WCROWCON Detecting Gas Saving Lives TXgard Plus Installation CSA Resistance Ohms per km Max distance mm2 awg Cable Loop m ft 1 0 17 18 1 36 2 1000 3280 1 5 15 12 1 24 2 1500 4920 Table 4 Maximum cable distances for typical cables Acceptable cross sectional area of cable is 0 5 to 1 5 mm Table 2 provides guidance only actual cable parameters for each application should be used to calculate maximum cable distances 3 4 Electrical connections All connections are made via the terminal board mounted in the base of the junction box see Diagram 2 The 3 wires from the 96HD are colour coded and should be terminated in the corresponding colour coded terminal terminals 4 5 amp 6 Terminals 1 0 Vdc 2 12 30 and 3 4 20mA signal are connected to the control equipment TXgard Plus is factory set as a 4 20 mA sink device unless specified otherwise when ordering see Section 2 to change configuration Diagram 3 summarises the electrical connections Note The junction box and cable armour must be earthed at the detector or control panel to limit the effect of radio frequency interference and to maintain electrical safety Note The junction box for the TXgard Plus is manufactured from marine grade alloy and has a powder coated finish Care should be taken during
3. 2 x M20 1 2 NPT for USA cable entries for customer use Alternative cable entries are available from Crowcon The amplifier plugs into the terminal board and is held in place by two captive screws The amplifier provides power to the sensor local display and controls and a 4 20 mA signal proportional to the gas concentration for connection to a control panel To remove turn screws anti clockwise and use them to pull amplifier out of the enclosure All electrical connections are made via the terminal board mounted in the base of the junction box see Diagram 2 Optional alarm relays AL1 amp AL2 and one fault relay FAULT are mounted on the terminal board which may be used to drive local warning devices or connect TXgard Plus to a control panel D CROWCON 1 Detecting Gas Saving Lives Introduction TXgard Plus 1 3 Status Indication TXgard Plus includes a local display and status LED visible through the junction box window see Diagram 1 The display shows the gas concentration and current mode of operation ie NORMAL ZERO or CAL The LED shows the current alarm state of the detector This is summarised in Table 1 Operational LED Relay states Comment state indication Normal Steady green AL1 Off Gas level lt AL1 operation AL2 Off Current output 4 20 mA FAULT On Normal Steady red AL1 On Gas level gt AL1 lt AL2 operation AL2 Off Current output 4 20 mA ALA
4. Table 2 Standard configuration for TXgard Plus 3 CROWCON 5 Detecting Gas Saving Lives Detector configuration TXgard Plus Table 3 details standard alarm points for the available gases and ranges Gas Range AL1 AL2 Hydrogen sulphide 0 25 ppm 5 ppm 10 ppm Carbon monoxide 0 250 ppm 30 ppm 200 ppm Oxygen 0 25 w 19 vv 17 w Alternative ranges and alarm set points must be specified when ordering Table 3 Standard ranges and alarm set points Location of links are shown in Diagram 2 2 2 4 20mA options To change current source output to sink set switch to SK position To change Inhibit from 2 mA to 4 mA fit link to 4 position 2 3 Relay options To change AL1 or 12 relay from NO to NC fit link in the NC position To change FAULT relay from NC to NO fit link in the NO position 2 4 Inhibit options To not inhibit 4 20 mA signal and relays fit link to N and link to 4 6 WCROWCON Detecting Gas Saving Lives TXgard Plus Installation 3 Installation WARNING TXgard Plus is designed for use in Zone 1 and 2 hazardous areas and is certified Ex d IIC T6 AEx d IIC T6 in USA Installation must be in accordance with the recognised standards of the appropriate authority in the country concerned For more information contact Crowcon Prior to carrying out any work ensure local regulations and site procedures are followed 3 1 Location There are no rules which
5. dictate the siting and location of detectors however considerable guidance is available from BS EN 50073 1999 British Standard Code of Practice for the Selection Installation Use and Maintenance of Apparatus for the Detection and Measurement of Combustible Gases or Oxygen In the USA refer to the National Electrical Code NEC 1999 Similar international codes of practice may be used where applicable In addition certain regulatory bodies publish specifications giving minimum gas detection requirements for specific applications The detector should be mounted where the gas is most likely to be present The following points should be noted when locating gas detectors e To detect gases which are lighter than air detectors should be mounted at high level and Crowcon recommend the use of a collector cone Part No C01051 To detect heavier than air gases eg hydrogen sulphide detectors should be mounted at low level When locating detectors consider the possible damage caused by natural events e g rain or flooding For detectors mounted outdoors Crowcon recommend the use of a Weatherproof Cap Part No C01442 Consider ease of access for functional testing and servicing Consider how the escaping gas may behave due to natural or forced air currents Mount detectors in ventilation ducts if appropriate J OCROWCON 7 Detecting Gas Saving Lives Installation TXgard Plus e Consider the process conditions ie whether
6. installation to protect the painted finish as use in saline environments could result in paint flaking off from damaged junction boxes This in no way compromises the performance of the detector as the marine grade alloy junction box is approved for use in offshore environments JCROWCON 9 Detecting Gas Saving Lives Installation TXgard Plus All electrical connections to the optional relays are made via the 6 way terminal block on the terminal board in the base of the junction box see Diagram 2 The relay contacts are rated 1 A 30 Vdc CONTROL EQUIPMENT SAFE AREA OV CONTROL EQUIPMENT SAFE AREA ui OV 4 20mA 12 30 V TXGARD PLUS SOURCE OV 20mA D gt B 12 30 V TXGARD PLUS SINK Diagram 3 Electrical connections to TXgard Plus 10 3 CROWCON Detecting Gas Saving Lives TXgard Plus Operation 4 Operation WARNING Prior to carrying out any work ensure local regulations and site procedures are followed Never attempt to open the detector or junction box when flammable gas is present Ensure that the associated control panel is inhibited so as to prevent false alarms 4 1 Commissioning Procedure a Open the junction box of the detector by loosening the tamper proof grub screw and removing the lid by rotating it anti clockwise b Remove the amplifier and check that all electrical connecti
7. RM 1 FAULT On Normal Flashing red AL1 On Gas level gt AL2 operation AL2 On Current output 4 20 mA ALARM 2 FAULT On Over range Flashing red AL1 On Gas level gt full scale AL2 On Display backlight flashes FAULT On Current output 24 mA Zero Flashing Configuration Latched until reset via MENU calibration green dependent Current output 2 mA mode see section 2 4 mA option Detector fault Steady AL1 Off Current output 0 mA amber AL2 Off FAULT Off See section 2 for AL1 and AL2 standard settings Relay version only Table 1 LED status indicator summary 2 WCROWCON Detecting Gas Saving Lives TXgard Plus Introduction 115 411 1 UNITS TAMPER PROOF M20 NTP GRUB SCREW CABLE ENTRY 1 5mm ALLEN KEY LOCAL DISPLAY M20 NTP STEADY ON CABLE ENTRY INDICATES FLASHING ZERO CAL TXgard Plus INDICATES 1 N 4 20mA RELAYS Cu INHIBITED D O ma ws OS 5 ALARM 1 amp 2 ADJUSTMENT POTS Menu 79L su 9 P di E LED DOWN eT Q A Y O QR EXTERNAL EARTH POINT 4 OFF FIXING HOLES E 6mm Y 83 347 HEIGHT 115 4 All dimmensions in mm unless otherwise stated Diagram 1 TXgard Plus general arrangement WCROWCON 3 Detecting Gas Saving Lives Introduction TXgard Plus
8. THORNE amp TED DERRICK INTERNATIONAL CROWCON www thorneandderrick com Detecting Gas Saving Lives TXgard Plus Flameproof Toxic and Oxygen Gas Detector TXgard Plu Menu CROWCONM Installation Operation and Maintenance Instructions M07194 Issue 5 March 2015 TXgard Plus Introduction 1 Introduction 1 1 Product overview TXgard Plus is a flameproof toxic and oxygen gas detector suitable for use in zone 1 or 2 hazardous areas It is designed to detect toxic gases and oxygen using a range of electrochemical sensors A local display and magnetically operated switches allow non intrusive one man calibration without a hot work permit Powered by 24 V dc nominally TXgard Plus provides a 4 20 mA signal sink or source proportional to the gas concentration and can also be fitted with optional alarm and fault relays For a list of gases that can be detected please contact Crowcon 1 2 Product description TXgard Plus comprises four parts 96HD sensor housing junction box amplifier and terminal board Diagram 1 details Txgard Plus The overall assembly is certified Ex d IIC T6 in Europe and Class 1 Zones 1 amp 2 AEx d IIC T6 in the USA The 96HD sensor housing is a modular stainless steel assembly that dismantles to allow plug in sensors to be replaced easily see Diagram 4 The assembly screws into an M20 entry on the junction box The junction box is manufactured from marine grade alloy and is supplied with
9. bly k Re assemble the 96HD housing taking time to ensure that the 3 mm Allen head screws are securely fixed into position Fit the 96HD sensor housing to the junction box ensuring that the colour coded wires are terminated correctly m Replace amplifier ensuring the captive screws are fastened securely n Switch on power 14 JCROWCON Detecting Gas Saving Lives TXgard Plus Operation o Close the junction box remembering to fasten the tamper proof grub screw into position p Follow the Commissioning Procedure given in 4 1 4 4 Changing Alarm Levels Relay Version Only WARNING This work should be carried out by Crowcon or an approved service centre unless suitable training has been received Before attempting to change alarm levels ensure the detector is in fresh air and no flammable gas is present Alarm levels are factory set as detailed in Table 3 To change either alarm level a Switch off and isolate power to the detector requiring attention b Open the junction box of the detector by loosening the tamper proof grub screw and removing the lid by rotating it anti clockwise c Remove the amplifier from the terminal board d Ensure that the INHIBIT link is set to N e Re fit the amplifier to the terminal board ensuring that all screws have been secured correctly f Apply power to the detector and allow the detector to stabilise g Place the end of CRO Mag over the MENU pad The decimal point above th
10. cations Zone 0 area classified as Zone O will have ignitable concentrations of flammable gases vapours or liquids present continuously or for long periods of time under normal operating conditions Zone 1 An area classified as Zone 1 is likely to have ignitable concentrations of flammable gases vapours or liquids present under normal operating conditions Zone 2 An area classified as Zone 2 is not likely to have ignitable concentrations of flammable gases vapours or liquids present under normal operating conditions 16 J CROWCON Detecting Gas Saving Lives TXgard Plus Spare parts and accessories 5 Spare parts and accessories Please refer to the Sensor Replacement Label mounted on the outside of the 96HD housing for the correct replacement part number Description Part number Complete 96HD sensor Sensor housing with sensor only Hydrogen sulphide 96HD HS 501750 E01229 Carbon monoxide 96HD CO 501751 E01344 Oxygen 96HD OX 501753 E01488 A M20 to 1 2 inch NPT adaptor M02125 M20 to 3 4 inch NPT adaptor M02281 Gasket 1 M04452 Gasket 2 M04128 Sinter removal tool M01614 Collector Cone 01051 Weatherproof 01442 Replacement CRO Mag C01697 Sinter assembly 501781 Amplifier Toxic version S01866 Amplifier Oxygen version 501867 Terminal board 501846 Relay board 501847 Loctite No 243 Calibration gas 3 CROWCON Detecting Gas Saving Lives Contact Crow
11. con Contact Crowcon 17 Specifications 6 Specifications TXgard Plus Dimensions 200 x 115x 115 mm 8 x 41 2 x 41 2 Weight 2 2 kg 4 8 Ibs Material 96HD sensor housing 316 Stainless steel Junction box Marine grade alloy Temperature range 10 C to 55 C 14 F to 131 F Humidity range 15 90 RH non condensing Ingress protection P65 Explosion protection Flameproof Approval codes E 112 G Ex d IIC T6 55 UL Class 1 Zones 1 amp 2 AEx d IIC T6 Safety Cert No Sira03ATEX1124 Standards EN60079 0 EN60079 1 2007 UL2279 Zones Certified for use in Zone 1 or Zone 2 areas see area classifications section Gas groups IA IIB IIC Operating voltage 12 30 Vdc Operating current Relay version 100 mA maximum Non relay version 50 mA maximum Detector output 4 20 mA source or sink selectable 0 mA Fault 2 mA Inhibit 4 mA option 4 20 mA Normal gas range 24 mA Over range Relays outputs 2 x Alarm relays SPNO SPNC option 1 x Fault relay SPNC SPNO option Contact rating 1 A 30 Vdc J CROWCON THOHNE amp TaD DERRICK INTERNATIONAL Detecting Gas Saving Lives www thorneandderrick com A HALMA COMPANY THORNE amp DERRICK INTERNATIONAL www thorneandderrick com
12. d isolate power to the detector requiring attention b Open the detector Junction box by loosening the tamper proof grub screw and removing the lid by rotating it anti clockwise c Remove the amplifier d Disconnect the 3 sensor wires from the terminal board terminals 4 5 amp 6 e Unscrew the complete 96HD sensor housing from the junction box Note If a spare 96HD sensor housing complete with new sensor is available ignore steps f to k and return the old 96HD to Crowcon or an approved service centre for repair f Open the 96HD sensor housing by removing the four Allen head screws from the Top Cap with a 3mm Allen key g Remove the sensor from the Top Cap PCB h Fit the replacement sensor checking the part number is correct This part number is labelled on the main body of the detector i Inspect the gaskets and replace if necessary j The sinter assembly will only need to be replaced if it has become blocked by dust or oil Such blockage causes the response time of the detector to be slow and may affect sensitivity To remove the sinter a removal tool Part M01614 is required Loctite No 243 must be used on the sinter assembly threads to maintain certification WCROWCON 13 Detecting Gas Saving Lives Operation TXgard Plus 4 OFF 4 X 12MM ALLEN HEAD sorews 2 NEOPRENE GASKET 1 Part No MO4452 GASKET 2 Part No MO4128 MAIN BODY SINTER ASSEMBLY Part No SO1781 SINTER Diagram 4 96HD assem
13. e word ZERO will illuminate the status LED will flash green and the display backlight will illuminate h With clean air present at the detector place the end of the CRO Mag key over the UP or DOWN arrow pads to make the display read the desired alarm level i Using a long instrument screwdriver turn the relevant ALARM SET pot mounted on the terminal board see Diagrams 1 amp 2 to adjust the alarm level Tripping of the ALARM 1 level relay is confirmed by the status LED turning a steady red Tripping of the ALARM 2 level relay is confirmed by the Status LED flashing red D CROWCON 15 Detecting Gas Saving Lives Operation TXgard Plus j Once the alarm level has been set place end of CRO Mag over the UP or DOWN arrow pads and reset the display to read zero k Place the end of the CRO Mag over the MENU pad to return the detector to normal operation ie No decimal points displayed backlight off and the Status LED indicating steady green Check that the detector operates correctly by applying test gas as necessary m Switch off and isolate power to the detector n Reset jumpers which may have been changed in step d above o Replace the amplifier and close the junction box ensuring that all screws have been re fitted correctly p Apply power to the detector and allow to stabilise before checking correct operation q Re calibrate if necessary as per section 4 1 Notes Area Classifi
14. gas within a process is at high temperature or high pressure Detector placement should be determined following advice of experts having specialist knowledge of gas dispersion the plant processing equipment as well as safety and engineering issues The agreement reached on the locations of sensors should be recorded 3 2 Mounting The mounting detail of TXgard Plus is given in Diagram 1 TXgard Plus should be installed at the designated location with the detector pointing down This ensures that dust or water will not collect on the sinter and stop gas entering the detector 3 3 Cabling requirement Cabling to TXgard Plus must be in accordance with the recognised standards of the appropriate authority in the country concerned and meet the electrical requirements of the detector Crowcon recommend the use of steel wire armoured SWA cable and suitable explosion proof glands must be used Alternative cabling techniques such as steel conduit may be acceptable provided appropriate standards are met TXgard Plus requires a dc supply of 12 30 V at up to 100 mA Ensure the minimum dc supply of 12 V is observed at the detector taking into account the voltage drop due to cable resistance For example a nominal dc supply at the control panel of 24 V has a guaranteed minimum supply of 20V The maximum voltage drop allowed is therefore 8V TXgard Plus can demand up to 100 mA and so the maximum loop resistance allowed is 80 Ohms A 1 0 mm2 cable
15. normal operation NORMAL Mode n Place the end of CRO Mag over the MENU pad All decimal points will disappear and the backlight will turn off The green status LED will be on steadily assuming no gas is present at the detector o The detector is now operational Note Always return the detector to NORMAL mode to avoid leaving the detector in a permanently inhibited state 4 2 Routine maintenance The operational life of the sensors depends on the application frequency and amount of gas being seen Under normal conditions 6 monthly calibration with periodic exposure to CAL gas the life expectancy of the detectors are Hydrogen sulphide 18 to 36 months Carbon monoxide 18 to 36 months Oxygen 24 months Site practices will dictate the frequency with which detectors are tested Crowcon recommend detectors are gas tested at least every 6 months and re calibrated as necessary following the steps given in 4 1 12 D CROWCON Detecting Gas Saving Lives TXgard Plus Operation 4 3 Sensor replacement servicing of detectors WARNING This work should be carried out by Crowcon or an approved service centre unless suitable training has been received TXgard Plus uses the 96HD sensor housing which allows the user to replace the sensors gaskets and sinter if necessary An exploded view of the 96HD sensor housing is given in Diagram 4 The following procedure may be followed when servicing a TXgard Plus detector a Switch off an
16. ons have been made and are correct as per Diagram 3 c Replace the amplifier and close the junction box ensuring that all screws have been re fitted correctly d Apply power to the detector The status LED will show a steady green indicating normal operation e Leave the detector to stabilise for 1 2 hours Zeroing the detector ZERO Mode f Place the end of CRO Mag over the MENU Green Status LED will flash Decimal point above ZERO will illuminate Display backlight will illuminate Decimal point above INHIBIT may flash if the option has been internally selected g With no flammable gas present at the detector place the end of the CRO Mag key over the UP or DOWN arrow pads to make the display read zero Note Oxygen detectors may be zeroed in fresh air Calibrating the detector CAL Mode h Place the end of the CRO Mag over the MENU pad The decimal point above the word CAL will illuminate Other indications remain unchanged i Apply calibration gas to the detector at a flow rate of 0 5 litres min contact Crowcon for the supply of calibration gas JCROWCON 11 Detecting Gas Saving Lives Operation TXgard Plus j Allow the gas reading to stabilise k Place the end of the CRO Mag over the UP or DOWN arrow pads to make the display read the correct concentration If the control equipment display requires adjustment consult the operating manual for the equipment Returning to
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