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WARNING
This detector is designed for use in Zone 1 and Zone 2
hazardous areas, and is certified 

II 2 GD EExd IIC T6 for

operation up to 50°C (122°F), 

II 2 GD EExd IIC T4 for

operation up to 80°C (176°F). Installation must be in
accordance with the recognised standards of the appropriate
authority in the country concerned. 
For further information please contact Crowcon. Prior to
carrying out any installation work ensure local regulations and
site procedures are followed.

2.1 Location

The detector should be mounted where the gas to be detected is most
likely to be present. The following points should be noted when locating
gas detectors:

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)

and accessory adaptor 

(Part No. M04666)

.

To detect heavier than air gases, 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 Spray Deflector (P

art No. C01052)

and accessory adaptor 

(Part No. M04666).

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.

Consider the process conditions. For example, butane is normally
heavier than air, but if released from a process which is at an elevated
temperature and/or pressure, the gas may rise rather than fall.

The placement of sensors 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.

Crowcon would be pleased to assist in the selection and siting of gas
detectors.

26

2. Installation

Xgard  Type 3

Summary of Contents for Crowcon Xgard

Page 1: ...Installation operating and maintenance instructions Xgard Gas Detectors M07249 Issue 8 October 2007...

Page 2: ...d when replacing cells to ensure that the electrolyte does not come into contact with skin or eyes Maintenance and calibration operations must only be performed by qualified service personnel Only gen...

Page 3: ...se in Zone 1 provided they are connected via a suitable zener barrier or galvanic isolator Zone 2 An area classified as Zone 2 is not likely to have ignitable concentrations of flammable gases vapours...

Page 4: ...ATEX and IECEx Intrinsically Safe Xgard Intrinsically Safe Type 1 UL Class I Groups A B C and D Haz Loc when installed in accordance with control CROWCON XGARD GAS DETECTOR TYPE 1 understand and adher...

Page 5: ...on Xgard comprises of a universal assembly to accommodate the full range of toxic flammable and oxygen gas sensors The assembly comprises five main parts the junction box junction box lid amplifier te...

Page 6: ...e entry 6 Overview Slots to suit M6 or 1 4 fixings 155 5 Overall Height 111 36 Slot CRS 146 CRS 166 3 Overall Slots to suit M6 or 1 4 fixings for ceiling mount All dimensions in millimetres Diagram 2...

Page 7: ...applicable For part numbers not shown see Spares and Accessories on page 59 7 Overview Grub screw Grub screw Certification label PCB cover M04770 Enclosure base Sensor seal Sensor retainer O ring M04...

Page 8: ...on 25 2 Installation 26 3 Operation 29 4 Specification 32 Type 4 Flameproof high temperature flammable gas detector 33 1 Introduction 33 2 Installation 34 3 Operation 37 4 Specification 40 Type 5 Flam...

Page 9: ...one 2 hazardous areas when used with a suitable Zener barrier or galvanic isolator Electrical connections to the detector are made via the terminal block on the amplifier PCB shown below The amplifier...

Page 10: ...damage caused by natural events e g rain or flooding For detectors mounted outdoors Crowcon recommend the use of a Spray Deflector Part No C01052 and accessory adaptor Part No M04666 Mounting of oxyg...

Page 11: ...a voltage higher than the maximum rating of the Zener barrier typically 28 V Ensure there is a minimum of 8 V at the detector taking into account the voltage drop due to cable resistance the Zener bar...

Page 12: ...be used where local authorities permit or require such a connection To limit radio interference the junction box and cable armour should be grounded earthed at the control panel Ensure the earth conn...

Page 13: ...DVM to the test points on the amplifier PCB Note At the test points Zero will read 40 mV 4 mA Full scale deflection will read 200 mV 20 mA Zeroing the detector 6 Ensure you are in clean air Adjust the...

Page 14: ...r board adjust the CAL pot until the DVM reads 174 mV 20 9 O2 Leave the LINK in RUN position and re fit the PCB cover 4 If the control equipment display requires adjustment consult the operating manua...

Page 15: ...ector by unscrewing the lid in an anti clockwise direction having loosened the retaining grub screw first 3 Unscrew the sensor retainer and remove the sensor and sensor PCB 4 Fit the replacement senso...

Page 16: ...or type Humidity 0 90 RH non condensing Degree of protection IP65 IP66 when fitted with a weatherproof cap Explosion protection Intrinsically Safe Approval code ATEX II 1 G EEx ia IIC T4 IECEx BAS 05...

Page 17: ...se in Zone 1 and Zone 2 hazardous areas Electrical connections to the detector are made via the terminal block on the amplifier PCB shown below The amplifier provides power to the sensor and converts...

Page 18: ...e g rain or flooding For detectors mounted outdoors Crowcon recommend the use of a Spray Deflector Part No C01052 and accessory adaptor Part No M04666 Mounting of oxygen detectors requires knowledge o...

Page 19: ...here is a minimum of 8 V at the detector taking into account the voltage drop due to cable resistance and the sense resistance of the control panel to which it is connected For example a nominal dc su...

Page 20: ...diagram 6 shall be used as the grounding means of the Xgard gas detector The external grounding terminal see diagram 6 is only a supplemental bonding connection and is only to be used where local aut...

Page 21: ...a digital volt meter DVM to the test points on the amplifier PCB Note At the test points Zero will read 40 mV 4 mA Full scale deflection will read 200 mV 20 mA Zeroing the detector 6 Ensure you are in...

Page 22: ...position and re fit the PCB cover 4 If the control equipment display requires adjustment consult the operating manual for the equipment 5 Follow steps 11 and 12 given in 3 1a above The detector is now...

Page 23: ...having loosened the retaining grub screw first 3 Unscrew the sensor retainer and remove the sensor and sensor PCB 4 Fit the replacement sensor having checked that the part number matches that stated...

Page 24: ...r type Humidity 0 90 RH non condensing Degree of protection IP65 IP66 when fitted with a weatherproof cap Explosion protection Flameproof Approval code ATEX II 2 GD EExd IIC T6 IECEx BAS 05 0042 Tamb...

Page 25: ...Bridge WB circuit and must be connected to a suitable control card The detector is certified II 2 GD EExd IIC T6 for operation up to 50 C 120 F II 2 GD EExd IIC T4 for operation up to 80 C 176 F and...

Page 26: ...air gases 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...

Page 27: ...Alternative cabling techniques such as steel conduit may be acceptable provided appropriate standards are met Maximum permissible cable lengths depend on the cable resistance and sensor being used It...

Page 28: ...nction box The terminals are marked sig and and correct polarity should be observed when connecting the detector to control equipment This version of Xgard operates as part of a 3 wire mV Wheatstone b...

Page 29: ...nstruction manual Zeroing the detector 6 Ensure you are in clean air Adjust the control equipment to read zero Calibrating the detector 7 Apply calibration gas concentration should be 50 LEL to the de...

Page 30: ...stor has been exposed Under normal conditions 6 monthly calibration with periodic exposure to CAL gas the life expectancy is 3 5 years Site practices will dictate the frequency with which detectors ar...

Page 31: ...ensor retainer and remove the sensor and sensor PCB 4 Fit the replacement sensor having checked that the part number matches that stated on the detector junction box label taking care to align the loc...

Page 32: ...y 0 99 RH non condensing Degree of protection IP55 IP66 when fitted with a weatherproof cap Explosion protection Flameproof Approval code ATEX II 2 GD EExd IIC T6 Tamb 40 C to 50 C ATEX II 2 GD EExd I...

Page 33: ...uitable control card The detector is certified II 2 G EExd IIC T3 and is suitable for use in Zone 1 and Zone 2 hazardous areas Electrical connections to the detector are made via the terminal block on...

Page 34: ...uld be mounted at low level When locating detectors consider the possible damage caused by natural events e g rain or flooding Consider ease of access for functional testing and servicing Consider how...

Page 35: ...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 provide...

Page 36: ...unction box The terminals are marked sig and and correct polarity should be observed when connecting the detector to control equipment This version of Xgard operates as part of a 3 wire mV Wheatstone...

Page 37: ...it at the control panel if necessary Refer to the control equipment instruction manual Zeroing the detector 6 Ensure you are in clean air Adjust the control equipment to read zero Calibrating the dete...

Page 38: ...l conditions 6 monthly calibration with periodic exposure to CAL gas the life expectancy is 3 5 years Site practices will dictate the frequency with which detectors are tested Crowcon would recommend...

Page 39: ...id in an anti clockwise direction having loosened the retaining grub screw first 3 Loosen the terminals retaining the detector wires 4 Loosen the grub screw on the sensor retainer 5 Unscrew the detect...

Page 40: ...ge Typically 10 mV per CH4 Minimum Operating temperature 20 C to 150 C 4 F to 302 F Humidity 0 99 RH non condensing Degree of protection IP54 Explosion protection Flameproof Approval code ATEX II 2 G...

Page 41: ...and provides a 4 20 mA signal sink or source proportional to the gas concentration The detector is certified II 2 GD EExd IIC T6 and is suitable for use in Zone 1 and Zone 2 hazardous areas Electrical...

Page 42: ...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 Spray Deflector Part No C...

Page 43: ...re met Xgard Type 5 requires a dc supply of 10 30 V at up to 100 mA Ensure there is a minimum of 10 V at the detector taking into account the voltage drop due to cable resistance For example a nominal...

Page 44: ...on as shown in Diagram 12 Note The internal grounding terminal see diagram 12 shall be used as the grounding means of the Xgard gas detector The external grounding terminal see diagram 12 is only a su...

Page 45: ...dc mV range and the potentiometer marked VR3 should be adjusted until the DVM reads 0 00 mV The PCB cover can now be replaced 6 To zero the detector reconnect the DVM to the test points marked TP1 an...

Page 46: ...checking the zero setting 12 Close the junction box of the detector ensuring that the lid is securely tightened and the grub screw is secured 13 The detector is now operational Note ATEX certified Xga...

Page 47: ...stor has been exposed Under normal conditions 6 monthly calibration with periodic exposure to CAL gas the life expectancy is 3 5 years Site practices will dictate the frequency with which detectors ar...

Page 48: ...to align the locating pins correctly with the slots in the junction box 5 Re fit the sensor retainer having first inspected the sinter to make sure that it has not become contaminated Contaminated it...

Page 49: ...sig terminal Relative to ve terminal common Operating temperature 40 C to 55 C 40 F to 131 F Humidity 0 99 RH non condensing Degree of protection IP65 IP66 when fitted with a weatherproof cap Explosi...

Page 50: ...temperature remains stable otherwise the sensor readings may be affected For a list of gas mixtures that can be detected using Xgard Type 6 please contact Crowcon Xgard Type 6 is powered by 24 V dc no...

Page 51: ...4 o d pipe Part No C01339 Crowcon recommend a flow rate of 0 5 1 litre minute and the sample gas must be suitably filtered to remove dust and moisture When locating detectors consider the possible da...

Page 52: ...et Xgard Type 6 requires a dc supply of 10 30 V at up to 100 mA Ensure there is a minimum of 10 V at the detector taking into account the voltage drop due to cable resistance For example a nominal dc...

Page 53: ...on as shown in Diagram 14 Note The internal grounding terminal see diagram 14 shall be used as the grounding means of the Xgard gas detector The external grounding terminal see diagram 14 is only a su...

Page 54: ...etails of the background gas This is normally air carbon dioxide nitrogen or argon Apply a sample of the background gas 100 volume concentration to the sensor at a flow rate of 0 5 1 litre minute via...

Page 55: ...setting Where the Range is the maximum value of the target gas and Gas is the concentration of the target gas in the calibration mixture Example calibrating a detector to measure 0 100 volume methane...

Page 56: ...detectors are tested Crowcon would recommend that detectors be gas tested at least every 6 months and re calibrated as necessary To re calibrate a detector follow the steps given in 3 1 The sinter sh...

Page 57: ...ction box of the detector by unscrewing the lid in an anti clockwise direction having loosened the retaining grub screw first 3 Unscrew the sensor retainer and remove the sensor and sensor PCB 4 Fit t...

Page 58: ...sig terminal Relative to ve terminal common Operating temperature 10 C to 55 C 50 F to 131 F Humidity 0 90 RH non condensing Degree of protection IP65 IP66 when fitted with a weatherproof cap Explosi...

Page 59: ...ring M04829 All Types Amplifier PCB for the following gas types S011238 2 Types 1 2 Carbon Monoxide Chlorine Chlorine Dioxide Hydrogen Hydrogen Sulphide Nitrogen Dioxide Sulphur Dioxide City Technolo...

Page 60: ...adaptor C011061 Spray deflector C01052 Spare parts and accessories Weatherproof cap C01442 Flow adaptor C01339 Collector cone C01051 Sun Shade C011063 Note these accassories are not compatible with X...

Page 61: ...igh levels of toxic or flammable gas will shorten the life of the sensor If the high level gas is corrosive e g hydrogen sulphide damage may occur over time to metal components Sensors may be cross se...

Page 62: ...ies may be rendered invalid if the use of an unauthorized charger is proven Non rechargeable batteries are excluded from this warranty Warranties on sensors assume normal usage and will be rendered in...

Page 63: ...l not affect a customer s statutory rights Crowcon reserves the right to apply a handling and carriage charge whereby units returned as faulty are found to require only normal calibration or servicing...

Page 64: ...10 421 0542 email eu crowcon com internet http www crowcon com USA Office Crowcon Detection Instruments Ltd 21 Kenton Lands Road Erlanger Kentucky 41018 1845 USA Tel 1 859 957 1039 or 1 800 527 6926 F...

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