SENSITRON
A Halma Company
MTEX4899
SMART S-MS MED
Manuale (IT)
P. 27/36
5. Installation
Only qualified personnel can install gas detectors, as described in Annex A of EN
60079-14 standard.
Warning
It’s strictly forbidden open and close the equipment when it’s installed in
hazardous area and it’s powered-on. This operation can be conducted in
safe zone and without power source. After 10 minutes from power source
interruption, the equipment can be opened.
It’s strictly recommended the use of personal protective equipment during
operations inside the enclosure
5.1
CORRECT MOUNTING
The gas detector is always to be mounted with the sensing element placed
downward.
For no reasons at all the enclosure can be drilled.
Wall mount the detectors by employing the existing holes.
Detectors with EPL Gb come complete with wall fixing brackets.
5.2
EARTH GROUND CONNECTION
The enclosure can be connected to the earth ground through one of the clamps
with anti-loosening locking washer and anti-rotation mechanical device.
To allow external earth ground connection, use a conductor with a minimum
section of 4 mm
2
.
To allow internal earth ground connection, use a conductor with a minimum
section of 1.5 mm
2
.
5.3
CABLE ENTRY
The cable entry accessories and holes’ closure must have Ex d/Ex tb protection
mode and they must be certified following ATEX 2014/34/EU directive.
Pipe ducts must comply with EN 60079-14 standard.
Thread type is described in the label (standard NPT ¾”).
In case of tapered thread, use a thread-lock glue (Loctite 243 for example) on 2-3
threads.
5.4
MAIN BOARD LAYOUT
Figure 1
Detector circuit layout
LED DL2 (green).
- WARM-UP:
Flashing 750mS ON ; 250mS OFF
- NORMAL MODE:
Flashing 1 sec ON ; 1 sec OFF.
indicates the detector's working condition
LED DL3 (Red)
External Watch-Dog status:
- Normal operation mode: LED Off
- Failure: LED on
LED DL1 (red)
RS485 TX-Data monitoring:
It lits when the detector is sending data to the Rs485 line
DL1
DL2
DL3
JP1
JP6
JP5
Power supply: Vcc-
Power supply: Vcc+
RS485:
A
RS485: B
4-20 mA
output
JP3
Sensor head connection
JP6:
Relay board or calibration keypad connection
JP3: RS485 end of line resistor
Closed: 120 ohm resistor connected
Open: 120 ohm resistor not connected
JP1
4
5
6
1
2
3
Not used
