Replacing The Sensor; Polytron Se Ex Pr M1/2 Dq And Se Ex Lc M1/2 Dq Sensing Heads - Dräger Polytron SE Ex PR M1 DQ Notice D'utilisation

Maintenance
The interval for regular calibration depends on the operating conditions. In
particular, regular checks must be performed to ensure that the gas inlet
opening on the sensor is in a condition that does not impair the gas infeed due
to corrosion or deposits (dust, oil, aerosol).
Every six months:
– Inspection by specialists.
The length of the inspection intervals must be established in each individual
case depending on safety considerations, process conditions, and the technical
requirements of the equipment. We recommend the Dräger maintenance
service for a service contract and for repair work.
If necessary:
– change the sensor. For further information, see the following chapter:
"Replacing the sensor", page 39.
5.2

Replacing the sensor

WARNING
Only replace the sensor when the control unit is switched off or with the
transmitter switched off in explosion-hazard areas. Even in safe areas, the
control unit or transmitter must first be deenergised to avoid potential damage to
the sensor.
Observe national regulations for the installation of electrical apparatus in
potentially explosive atmospheres (in Europe EN 60 079-14)!
1. Deenergise the control unit.
2. Disconnect the transmitter from the supply.
5.2.1 Polytron SE Ex PR M1/2 DQ and SE Ex LC M1/2 DQ
sensing heads
1 2 3
1. After switching off the operating voltage, open the sensing head terminal
box and remove the upper part.
2. Unfasten the sensor lines
3. Unscrew the hexagon nut(s).
4. Unscrew the old sensor, shorten the sensor lines for the new sensor as
appropriate and strip by approx. 8 to 10 mm. Use the ferrules provided.
WARNING
To preserve the IP 66 protection rating and for explosion protection reasons,
ensure that the sensor sealing ring and the flat silicone gasket included with the
sensor are correctly seated.
5. Screw in the new DrägerSensor (torque: 15 ±3 Nm) and secure against self-
loosening with a hexagon nut, e.g. Loctite no. 221.
6. Connect the sensors lines on the new sensor to the terminals:
Terminal 1
Terminal 2
Terminal 3
1 2 3
brown line
yellow line
black line