Xgard IR
Gas Detector
Installation, operating
and maintenance
instructions
M07648
Issue 1 June 2007
Safety information
• Xgard IR gas detectors must be installed, operated and maintained in strict
accordance with these instructions, warnings, label information, and within the
limitations stated.
• The lid on Xgard IR must be kept tightly closed until power to the detector is
isolated otherwise ignition of a flammable atmosphere can occur. Before removing
the cover for maintenance or calibration purposes, ensure the surrounding
atmosphere is free of flammable gases or vapours.
• Maintenance and calibration operations must only be performed by qualified
service personnel.
• Only genuine Crowcon replacement parts must be used, substitute components
may invalidate the certification and warranty of the detector.
• Xgard IR detectors must be protected from extreme vibration, and direct sunlight
in hot environments as this may cause the temperature of the detector to rise
above its specified limits and cause premature failure.
• This equipment must not be used in a Carbon Disulphide atmosphere.
• Xgard IR will not detect hydrogen.
Hazardous area classifications:
Zone 0: An area classified as Zone 0 will have ignitable concentrations of
flammable gases, vapours or liquids either continuously present or
present for long periods of time under normal operating conditions.
Intrinsically Safe (Exia) detectors are suitable for use in Zone 0, provided
they are connected via a suitable zener barrier or galvanic isolator.
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. Flameproof (Exd) detectors are suitable for use in Zone 1.
Intrinsically Safe (Exia) detectors are suitable for use 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 or liquids present under normal operating
conditions. Flameproof (Exd) detectors are suitable for use in Zone 2.
Intrinsically Safe (Exia) detectors are suitable for use in Zone 2, provided
they are connected via a suitable zener barrier or galvanic isolator.
Notes:
In North America ‘Divisions’ are used to categorise risk where:
Division 1 is equivalent to Zone 0 or 1
Division 2 is equivalent to Zone 2
Under European ATEX rules hazardous area equipment has been redefined under
‘equipment categories’ where:
Equipment Category 1 is suitable for Zone 0
Equipment Category 2 is suitable for Zone 1
Equipment Category 3 is suitable for Zone 2
1
Overview
Product overview
Xgard IR is an infrared gas detector, which is available in two versions for
the detection of :
• Common hydrocarbon gases in the range 0100%LEL.
• Carbon dioxide in the range 02% volume or 05% volume.
Xgard IR is a certified Flameproof (Exd) detector suitable for use in ATEX
Zone 1, Zone 2, Zone 21 or Zone 22 hazardous areas.
UL certified versions are suitable for use in Division 1 or Division 2 areas.
Please refer to the certification label on the detector junction box to
identify the type of certification that relates to the product supplied.
Hazardous area definitions are shown in the Hazardous area
classifications section on page 1.
Note: if no certification label is fitted to the junction box, the
detector is not certified for use in hazardous areas.
XGARD GAS DETECTOR TYPE
o o
CROWCON
o A SS IF I
4 0 oF < Ta <+12 2 F T 6 4 0 F < Ta <+1 7 6 F T 4
CL
ED
1180 II 2GD
Vmax=32v Wmaxo =10W o Class 2 1030VDC Wmax=10W 66Y6
EEx d IIC T4 4 0o C < Ta < + 8 0oC CLASS I, DIVISION 1, GROUPS B, C, & D
EEx
o
d IIC T6 o
4 0 Co< Ta< + 5 0 C o AS TO RISK OF FIRE, ELECTRIC SHOCK & EXPLOSIVE HAZARDS ONLY.
T 8 0 C Ta m b = 5 0 C T 1 1 0 C Ta m b = 8 0 C WARNING To reduce the risk of ignition of Hazardous Atmosheres
Baseefa04ATEX0024X disconnect the equipment from the supply circuit before opening.
Xgard Gas Detector
Keep assy tightly closed when in operation. Conduit runs must have
sealing fitting connected within 18 inches of enclosure. 2006
OX14 1DY
Ex d IIC T4
Ex tD A21 IP6x
4 0oo C <Ta <+8 0oC
Xgard UL certification label
Ex d IIC T6 4 0 C <Ta <+5 0oC
IECEx BAS 05.0043X
WARNING Do not open when
an explosive atmosphere
is present
ATEX certification label
Diagram 1: Xgard IR certification labels
2
Overview
Each version of Xgard IR is identified by a label fitted on the junction box
body. Please quote the ‘model number’, ‘gas range’ and ‘sensor type’
when contacting Crowcon for advice or spares.
Product description
Xgard IR comprises of a universal assembly to accommodate either HC
or CO2 IR gas sensors. The assembly comprises five main parts; the
junction box, junction box lid, amplifier/terminal PCB, sensor PCB and
sensor retainer. These are shown in exploded form in Diagram 3.
A cover is fitted over the amplifier PCB to provide protection when the
junction box is opened. This cover is designed to allow access to all cable
terminals, test points and potentiometers without the need for removal.
The junction box is manufactured from marine grade aluminium with a
durable polyester coating (stainless steel option is available). The junction
box is supplied with 1 x M20, ½" or ¾" NPT cable gland entry, on the right
hand side for customer use. The junction box is suitable for fixing on the
wall or ceiling using M6 or ¼" fixings. Cable gland adaptors are available
if required (see Spare parts and accessories section).
3
Overview
36 Slot
CRS
Slots to suit M6
or 1/4” fixings
for ceiling mount
cable entry
M20, 1/2” or 3/4” NPT
155.5 Overall
Slots to suit M6 or 1/4” fixings
146 CRS
166.3 Overall
Height 111
All dimensions in millimetres
Diagram 2: Xgard IR dimensioned view
4
Overview
Certification label
Grub screw
PCB cover
(M04770)
Lid O-ring
(M04829) Enclosure
base
Amplifier PCB
Sensor module
Sensor seal
(M04885)
Sensor retainer
O-ring (M04828)
Grub screw
Sensor retainer
(M01814)
Diagram 3: Xgard IR exploded view (part numbers shown in brackets where applicable)
5
1. Introduction Xgard IR
1.1 Flameproof flammable gas detector
Xgard IR is a flameproof gas detector, designed to detect hydrocarbon
gases or CO2. Xgard IR is powered by 24 V dc (nominally) and provides
a 420 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, Zone 2, Zone 21 and Zone 22 hazardous areas.
Electrical connections to the detector are made via the terminal block on
the PCB shown below.
Internal grounding
terminal (earth)
TP2
Sink
Supplemental
external
grounding
terminal
Test (earth)
points
Srce
TP1
Diagram 4: Xgard IR PCB layout
(Shown with PCB cover removed).
6
2. Installation Xgard IR
WARNING
This detector is designed for use in Zone 1, Zone 2, Zone
21 and Zone 22 hazardous areas, and is certified II 2 GD
EExd IIC T6. 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, such as methane, 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, such as flammable vapours or CO2,
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 (Part No. C01052).
• 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.
7
2. Installation Xgard IR
2.2 Mounting
Xgard IR should be installed at the designated location with the sensor
pointing down. This ensures that dust or water will not collect on the
sensor and stop gas entering the cell. The mounting detail is shown in
Diagram 2. Care should be taken when installing the detector to avoid
damaging the painted surface and screw threads of the junction box and
sensor retainer.
2.3 Cabling requirement
Cabling to Xgard IR 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.
Xgard IR requires a dc supply of 1030 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 supply at the control
panel of 24 V has a guaranteed minimum supply of 18 V. The maximum
voltage drop is therefore 8 V. Xgard IR can demand up to 100 mA and so
the maximum loop resistance allowed is 80 Ohms.
A 1.5 mm2 cable will typically allow cable runs up to 3.3 km. Table 1 below
shows the maximum cable distances given typical cable parameters.
C.S.A. Resistance (Ohms per km) Max. Distance
mm2 Awg Cable Loop (km)
1.0 17 18.1 36.2 2.2
1.5 15 12.1 24.2 3.3
2.5 13 7.4 14.8 5.4
Table 1: maximum cable distances for typical cables
The acceptable cross sectional area of cable used is 0.5 to 2.5 mm2
(20 to 13awg). The table is provided for guidance only, actual cable
parameters for each application should be used to calculate
maximum cable distances.
8
2. Installation Xgard IR
2.4 Electrical connections
All connections are made via the screw terminal block mounted on the
PCB in the junction box. The terminals are marked ‘+’, ‘sig’ and ‘’ and
correct polarity should be observed when connecting the detector to
control equipment. Xgard IR is factory set as a ‘current sink’ device
unless otherwise specified when ordering. To reset to ‘current source’,
open the junction box and move the two links on the amplifier PCB from
the ‘sink position to the ‘srce’ position, as shown in Diagram 4.
Note: The internal grounding terminal (see diagram 4) shall be used as
the grounding means of the Xgard gas detector. The external grounding
terminal is only to be used where local authorities permit or require such
a connection. Where possible, to limit radio frequency interference, the
junction box and cable armour should be grounded at the control panel
(safe area) only to avoid earth loops.
XGARD IR PCB CONTROL PANEL
-VE -VE 1 2 3 4 5 6 7 8 9 10 11 12
SIG SIG
+VE +VE
Earth
10-30 V DC
4-20 mA
(Sink or Source)
Diagram 5: Xgard IR electrical connections
9
3. Operation Xgard IR
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.
3.1 Commissioning procedure
1. Open the junction box of the detector by unscrewing the lid in an anti
clockwise direction (having loosened the retaining grubscrew first).
2. Check that all electrical connections have been made and are correct,
as shown in Diagram 5.
3. Measure the voltage across the ‘+’ and ‘’ terminals and check a
minimum supply of 10 V d.c. is present.
4. Leave the detector to stabilise for at least 45 minutes.
5. To zero the detector, connect the DVM to the test points marked ‘TP1’
and ‘TP2’ on the amplifier PCB, as shown in Diagram 4.
Note: At the test points, Zero will read 40 mV = 4 mA.
Full scale deflection will read 200 mV = 20 mA. There is a current
clamp of 25 mA on the 420 mA output.
Zeroing the detector
6. Ensure you are in clean air. Adjust the ‘ZERO’ pot on the amplifier
(which is accessible via a hole in the PCB cover) until the DVM reads
40 mV. Check that the control equipment display reads zero.
Calibrating the detector
7. Apply calibration gas (concentration should ideally be at least 50% of
full scale concentration) to the detector at a flow rate of 0.5–1
litre/minute via a flow adaptor (Part No. C03005). Contact Crowcon
for the supply of calibration gas.
8. Allow the gas reading to stabilise (usually 30 to 60 seconds) and adjust
the ‘CAL’ pot until the DVM reads the appropriate reading (eg for a
hydrocarbon gas detector 120 mV = 12 mA = 50% LEL). If the
concentration of the calibration gas used is not 50% of scale, the
following formula can be used to calculate the reading:
160
( Range )
x Gas + 40 = mV setting
Example: calibrating a 05% CO2 detector using 3% CO2 test gas
10
3. Operation Xgard IR
( 160
5
x3 ) + 40 = 136 mV
9. If the control equipment display requires adjustment consult the
operating manual for the equipment.
10. Remove the gas and allow the sensor to completely settle before re
checking the zero setting.
11. Close the junction box of the detector ensuring that the lid is securely
tightened, and the grubscrew is secured.
12. The detector is now operational.
Note: ATEX Certified Xgard IR detectors will be supplied calibrated for
compliance with EN61779 (where, for example, 100% LEL Methane = 4.4%
volume). UL\CSA certified detectors will be supplied calibrated for
compliance with ISO10156 (where 100% LEL Methane = 5% volume).
11
3. Operation Xgard IR
3.2 Routine maintenance
Site practices will dictate the frequency with which detectors are tested.
Crowcon would recommend that detectors be gas tested at least every 6
months and recalibrated as necessary. To recalibrate a detector follow
the steps given in 3.1.
The sinter should be inspected regularly, and replaced if it has become
contaminated. A blocked sinter may prevent gas from reaching the
sensor.
When performing maintenance on Xgard IR, ensure that the sensor
retainer and junction box lid Orings are present and in good condition to
maintain the ingress protection of the product. See the ‘Spare parts and
accessories’ section for the part numbers of replacement Orings.
The sensor used in Xgard IR should provide in excess of 5 years trouble
free operation. In the event of a sensor failure, the sensor module should
be replaced.
3.3 Changing Gas Types.
Each Xgard IR detector is supplied precalibrated for a particular type of
gas (for example methane, propane or CO2). If recalibration for a different
gas type is required, the Xgard IR detector should be returned to
Crowcon for modification. Please contact Crowcon for further details.
12
3. Operation Xgard IR
3.4 Sensor replacement/servicing of detectors
Xgard IR uses a modular design, which makes replacement of sensors,
or sinters extremely simple. Replacement sensors are supplied fitted to a
sensor PCB to allow simple plugin installation. An exploded view of
Xgard IR is given in Diagram 3. The following procedure may be followed
when servicing a Xgard IR detector.
WARNING
This work should be carried out by Crowcon or an approved
service centre unless suitable training has been received.
1. Switch off and isolate power to the detector requiring attention.
2. Open the junction box of the detector by unscrewing the lid in an anti
clockwise direction (having loosened the retaining grubscrew first).
3. Unscrew the sensor retainer and remove the sensor and sensor PCB
(having also removed its grub screw).
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 locating pins correctly with the slots in the junction box.
5. Refit the sensor retainer having first inspected the sinter to make sure
that it has not become contaminated. Contaminated items should be
replaced (see Spare Parts section for replacement part numbers), as
any blockages may result in slow sensor response to gas, and
reduced sensitivity.
6. Follow the Commissioning Procedure given in 3.1.
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4. Specification Xgard IR
Junction box material A356 marine grade alloy with polyester
powder coating
316 Stainless Steel (optional)
Dimensions 156 x 166 x 111 mm (6.1 x 6.5 x 4.3 inches)
Weight Alloy: 1 kg (2.2 lbs)
Stainless Steel: 3.1 kg (6.8 lbs) approx.
Operating voltage 1030 V dc
Current consumption 67 mA @ 10 V, 50 mA @ 24 V
Output 420 mA Sink or Source (Selected by Links)
Fault Signal < 3 mA
Maximum cable 40 Ohms @ 18 V (power) +ve terminal
loop resistance 450 Ohms @ 18 V (signal) sig terminal
Relative to ve terminal (common)
Operating temperature 20°C to +55°C (4°F to +131°F)
Humidity 0–95% 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
Tamb = 40°C to 50°C
ATEX II 2 GD EExd IIC T4
Tamb = 40°C to +80°C
UL Class I, Division 1, Groups B, C & D
IECEx Exd IIC T6 , Exd IIC T4
Safety certificate no. Baseefa 04ATEX0024X and
IECEx BAS05.0043X
Standards EN50014, EN50018, UL1203
Zones Certified for use in Zone 1 or Zone 2
(see hazardous area classifications section)
Gas groups IIA, IIB, IIC, (UL groups B,C,D)
EMC EN50270
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5. Spare parts and accessories Xgard IR
Description Part Numbers
Sensor retainer with sinter (aluminium) M01814
Sensor retainer with sinter (stainless steel) M01913
Sensor seal (stainless steel retainer) M04971
Sensor seal (aluminium retainer) M04885
Sensor retainer Oring M04828
Junction box lid Oring M04829
Amplifier PCB S011242/2
PCB cover M04770
Calibration adaptor C03005
Duct mounting kit S011918
Spare Sensor Module Contact Crowcon
Accessory adaptor Spray deflector
C011061 C01052
Weatherproof cap Flow adaptor
C01442 C01339
Collector cone Sun Shade
C01051 C011063
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Warranty
This equipment leaves our factory fully tested and calibrated. If within the warranty
period of two years from Despatch, the equipment is proved to be defective by reason
of faulty workmanship or material, we undertake at our option either to repair or
replace it free of charge, subject to the conditions below.
Warranty Procedure
To facilitate efficient processing of any claim, contact our customer support team on
+44 (0)1235 557711 with the following information:
Your contact name, phone number, fax number and email address.
Description and quantity of goods being returned, including any accessories.
Instrument serial number(s).
Reason for return.
Obtain a Returns form for identification and traceability purpose. This form may be
downloaded from our website ‘crowconsupport.com’, along with a returns label,
alternatively we can ‘email’ you a copy.
Instruments will not be accepted for warranty without a Crowcon Returns
Number (“CRN”). It is essential that the address label is securely attached to the
outer packaging of the returned goods.
The guarantee will be rendered invalid if the instrument is found to have been altered,
modified, dismantled, or tampered with. The warranty does not cover misuse or abuse
of the unit.
Any warranty on batteries may be rendered invalid if the use of an unauthorized
charger is proven. Nonrechargeable batteries are excluded from this warranty.
Warranties on sensors assume normal usage, and will be rendered invalid if the
sensors have been exposed to excessive concentrations of gas, extended periods of
exposure to gas or have been exposed to ‘poisons’ that can damage the sensor, such
as those emitted by aerosol sprays
Warranty Disclaimer
Crowcon accept no liability for consequential or indirect loss or damage howsoever
arising (including any loss or damage arising out of the use of the instrument) and all
liability in respect of any third party is expressly excluded.
This warranty does not cover the accuracy of the calibration of the unit or the
cosmetic finish of the product. The unit must be maintained in accordance with the
Operating and Maintenance Instructions.
The warranty on replacement consumable items (such as sensors) supplied under
warranty to replace faulty items, will be limited to the unexpired warranty of the
original supplied item.
Crowcon reserves the right to determine a reduced warranty period, or decline a
warranty period for any sensor supplied for use in an environment or for an application
known to carry risk of degradation or damage to the sensor.
Our liability in respect of defective equipment shall be limited to the obligations set out
in the guarantee and any extended warranty, condition or statement, express or
implied statutory or otherwise as to the merchantable quality of our equipment or its
16
Warranty
fitness for any particular purpose is excluded except as prohibited by statute. This
guarantee shall 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, which the
customer then declines to proceed with.
For warranty and technical support enquiries please contact:
Customer Support
Tel +44 (0) 1235 557711
Fax +44 (0) 1235 557722
Email warranty@crowcon.com
17
UK Office USA Office
Crowcon Detection Instruments Ltd, Crowcon Detection Instruments Ltd,
2 Blacklands Way, 21 Kenton Lands Road
Abingdon Business Park, Erlanger
Abingdon, Kentucky 410181845
Oxfordshire OX14 1DY, UK USA
Tel: +44 (0)1235 557700 Tel: +1 859 957 1039 or
Fax: +44 (0)1235 557749 1800527 6926
email: sales@crowcon.com 18005CROWCON
internet: http://www.crowcon.com Fax: +1 859 957 1044
email: salesusa@crowcon.com
internet: http://www.crowcon.com
Rotterdam Office Singapore Office
Crowcon Detection Instruments Ltd, Crowcon Detection Instruments Ltd,
Vlambloem 129 Block 194, Pandan Loop
3068JG, Rotterdam #0620 Pantech Industrial Complex
Netherlands Singapore 128383
Tel:+31 10 421 1232 Tel:+65 6745 2936
Fax: +31 10 421 0542 Fax: +65 6745 0467
email: eu@crowcon.com email: sales@crowcon.com.sg
internet: http://www.crowcon.com internet: http://www.crowcon.com
1180
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