Maintenance
Change of the electronic board:
Deenergise device and secure against being switched on again.
Before opening the lid take care, that the unit is clean an no water
or dirt can enter into the housing.
1. Open the housing lid.
2. Remove the eld wiring cables.
3. Remove the internal functional ground cable.
4. Unscrew the two fastening screws of the electronic board.
5. Take out the electronic board.
6. Remove the plug to the probe.
7. Connect the plug to a new electronic board.
8. Insert the new electronic board and tighten fastening screws.
9. Connect the functional ground cable and the eld wire cables.
Calibration is not required.
CN 4030
CN 4050
For these types a non changeable electronic is located inside the
probe. Please return defective units to the manufacturer.
CN 4020
Opening the lid (cover) Before opening the lid for maintenance reasons observe following items:
• Do not remove the lid while circuits are alive.
• No dust deposits or whirlings are present.
• No rain can enter into the housing.
Frequent check of the
unit
To ensure durable safety in hazardous locations and with electrical safety, following items must be
checked frequently depending on the application:
• Mechanical damage or corrosion of any components (housing side and sensor side) and of the eld
wiring cables.
• Thight sealing of the process connection, cable glands and enclosure lid.
• Properly connected external PE cable (if present).
Cleaning If cleaning is required by the application, following must be observed:
• Cleaning agent must comply with the materials of the unit (chemical resistance). Mainly the lid
sealing, cable gland and the surface of the unit must be considered.
The cleaning process must be done in a way, that:
• The cleaning agent cannot enter into the unit through the lid sealing or cable gland.
• No mechanical damage of the lid sealing, cable gland or other parts can happen.
A possible accumulation of dust on the unit does not increase the maximum surface temperature and
must therefore not be removed for purposes of maintaining the surface temperature in hazardous
locations.
Function test A frequent function test may be required depending on the application.
Observe all relevant safety precautions related with a safe work depending on the application (e.g.
hazardous locations, hazardous bulk material, electric safety, process pressure).
This test does not proof if the sensor is sensitive enough to measure the material of the application.
Function test is done by touching the sensor part with appropriate means (e.g. grounded metal plate or
hand) and monitor if a correct change of the signal output from uncovered to covered happens.
Production date The production date can be traced by the serial number on the typeplate. Please contact the
manufacturer or your local distrubutor.
Spare parts All available spare parts are stated in the selection list