Installation; Hazardous Area Use; Location - Crowcon Xgard Bright Bedienungsanleitung

3. INSTALLATION

3.1 Hazardous Area Use

WARNING
This detector is designed for use in Zone 1 and Zone 2 or Zone 21 and Zone
22 hazardous areas, and is certified Ex db IIC T6 Gb and Ex tb IIIC T80°C Db
for operation up to 70°C (158°F). Installation must be in accordance with the
recognized standards of the appropriate authority in the country concerned. For
further information please contact Crowcon. Prior to carrying out any installa-
tion work ensure local regulations and site procedures are followed.

3.2 Location

The detector should be mounted where the gas to be detected is most likely to be
present. 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 sen-
sors should be recorded.
The detector should be mounted where the gas to be detected is most likely to be pre-
sent. 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).
• 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 (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 pres-
sure, the gas may rise rather than fall.
• Location of oxygen sensors requires knowledge of the gas that may displace the
oxygen. For example, carbon dioxide is denser than air and therefore is likely to
displace oxygen from low levels upwards.
• Sensors should be mounted at head height (1.5m nominally) to detect gases of a
similar density to air, assuming that ambient conditions and the temperature of the
target gas are nominally 20˚C.
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Xgard Bright