Mycom S CPM 153
7 Maintenance
Hauser
89
7
Maintenance
CPM 153 does not contain wear parts and is maintenance free.
Measuring point maintenance comprises:
•
cleaning the assembly and electrode
•
inspecting cables and connections,
•
calibration (see page 83).
#
Warning!
Danger to persons. If you have to remove the electrode for servicing or calibration work,
pay attention to the hazards caused by pressure, temperature and contamination.
"
Caution!
Remember that any maintenance work on the instrument, assembly or electrodes may
have impacts on process control and the process itself.
7.1
Maintaining the measuring system
7.1.1
Cleaning
•
Dependent on the process, and as far as necessary, the assembly, cable and
electrode must be cleaned externally before inspection and calibration. For your own
safety always follow the safety instructions (see above). If necessary wear protective
clothing.
•
Cleaning the sensors see Chap. 7.1.3.
7.1.2
Checking cables and connections
Please check cables and connections using the following checklist. As there are many
different combination possibilities, these instructions are kept to a general level and
must be applied to the current installation.
•
Check the electrode plug-in head for sealing and humidity.
•
Check the sensor cable and particularly the outer insulation for breaks.
•
Sensor cables which have become damp on the inside must be replaced.
Only drying is not sufficient!
•
If you are using a junction box: The inside of the box must be clean and dry. Moist
dehydrating bags must be replaced.*
•
Retighten the terminals in the junction box.*
•
For in-field instruments:
Retighten the terminals in the instrument. Also check the interior and the PCBs are
clean, dry and free of corrosion (if not: check the seals and screw unions for leaks and
breaks). *, **
•
For panel-mounted units:
retighten the terminals on the instrument, check the BNC connector. *, **
•
Cable screens must be connected exactly as shown in the wiring diagram. If the
screen is connected incorrectly or not at all, the fail-safety of the instrument could be
impaired.
*: The frequency of these checks is dependent on environmental influences. In a normal
climate and non-aggressive environment, an annual check is sufficient.
**: This work may only be carried out on a voltage-free instrument, as some of the
terminals carry mains voltage.
