User's Manual

Page 66 Sitrans LR 400 – INSTRUCTION MANUAL 7ML19985FH01
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Maintenance
5. Lift the device fuse carefully from its clip with a suitable tool (tweezers, flat-tipped
pliers or similar) (see above), and remove it from the housing.
6. Insert a new fuse. Only use original spare fuses! Press it into the clip until it snaps in
audibly.
7. Reassemble the device in reverse order.
Disconnecting the electronics part from the
mechanical part
For maintenance it is possible to separate the electronic enclosure of the device from the
mechanical part (flange) without endangering the pressure tightness of the vessel.
Release the threaded ring of the electronics part from the mechanical part with a hook
key 68/75 and remove the electronics part. Place the enclosed plastic cap on the
mechanical part to prevent from soiling.
Cleaning the antenna
Depending on the type of measuring material, it may be necessary to clean the antenna
at certain intervals to remove soiling which could affect the measuring result. You can
clean it without removing the flange from the vessel. Proceed as follows:
1. Disconnect and remove the electronics part as described above.
2. Unscrew the pressure window which becomes accessible after removing the
threaded ring with an M36 open-ended wrench and lift it off the mechanical part
together with the white PTFE stopper.
3. Clean the inside of the antenna with compressed air and/or a brush. Make
especially sure that the pressure window thread is clean. Apply fresh grease to the
thread as required. Check the O-rings for damage and replace them if necessary.
4. If the PTFE stopper has come loose when removing from the pressure window,
reinsert it long end first in the mechanical part. Push it into the guide up to its
thickened stop.
5. Place the pressure window and screw it tight.
6. Reattach the electronics part to the mechanical part. You can align the rotatable
housing head before tightening the threaded ring.
7. Check the pressure tightness of the vessel.
Caution! The device contains a second fuse that is not accessible via the front side.
This fuse is only to be replaced by the manufacturer (following a complete safety
check of the device).
Caution! As soon as you remove the pressure window from the mechanical part the
vessel is no longer pressure-tight and explosion protected!
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