SENSITRON
A Halma Company
MTEX4899
SMART S-MS MED
Manuale (IT)
P. 25/36
3. Installation site
prearrangement
3.1
SUITABILITY OF DETECTORS IN RELATION TO THE AREA OF INSTALLATION
If the detector is installed in a hazardous area, the user has to verify that the
equipment is suitable for the classified area and for the flammable substances
present.
Th safety essential requirements against explosion risk in classified areas are
described by European directives 2014/34/UE of 26/02/2014 and 1999/92/CE of
16/12/1999.
The criteria to classify hazardous areas are described in the standard EN
60079-10-1 (for explosive gas) and in the standard EN 60079-10-2 (for explosive
dusts). The technical requirements for electrical systems in classified areas are
reported in the standard EN 60079-14.
Following the mentioned dispositions, the user has to choose the gas detector
type on the basis of these factors:
-
System type: Group II
-
Zone classification: 1, 2.
-
Zone classification: 21, 22.
-
Gas group: IIA, IIB or IIC
-
Dust group: IIIA, IIIB or IIIC
-
Gas temperature class: T*
.
Maximum dusts’ superficial temperature: * °C
* see data reported on the label
3.2
GENERAL PRECAUTIONS
General precautions
At the mounting and installation phase, be sure all safety precautions have been
considered. Always remember how important the correct positioning of gas
detectors is to get the optimum response.
Be careful:
-
Never to install gas detectors close to air intakes or fans causing strong
air currents.
-
The detectors are attached to a firm base to prevent vibration that can
damage them, producing unreliable results. Although the electronics
comply with the electromagnetic compatibility rules, it is advised to
keep the detectors at a distance from any radio frequency senders
(such as radio links or similar).
-
That detectors are placed in a convenient location for future
maintenance and calibration requirements
3.3
ENVIRONMENT CONDITIONS
The gas detector can be used in the temperature range reported on the label. It
is suitable for indoor and outdoor installations, depending on dust protection, IP
grade and relative humidity reported on the label.
3.4
PRECAUTIONS BASED ON THE GAS TO DETECT AND ENVIRONMENTAL INHIBITORS
When preparing the installation site, it is necessary to take into account the
nature of the gas to be detected and the presence of chemical agents in the
environment
-
All of the gases lighter than air (Methane, Hydrogen, Ammonia) tend
to spread upwards; the detector should be placed at 30 cm from the
Table 4
Operating conditions
Operating temperature
-40/-20 : +50/ +55/ +60/ +65 °C
Relative humidity
20 - 90 %Rh / 40°C
Operating pressure
80 - 120 kPa with catalytic sensor
86 – 120 kPa with infrared sensor