15
English
3.3 Changing Gas Types
Each
Xgard IR
detector is supplied pre-calibrated for a particular type of gas (for
example methane, propane or CO
2
). If re-calibration for a different gas type is required,
the
Xgard IR
detector should be returned to Crowcon for modification. Please contact
Crowcon for further details.
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 plug-in installation. An exploded view of
Xgard IR
is given in Diagram 3. The
following procedure may be followed when servicing a
Xgard IR
detector.
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 grub-screw 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 cor
-
rectly with the slots in the junction box.
5. Re-fit 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.
WARNING
This work should be carried out by Crowcon or an approved service centre
unless suitable training has been received.
