KROHNE OPTIMASS with MFC 300 EN - Manual (Page 136)

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11.4 Replacing the Sensor or Converter Electronics
If a failure occurs in one the above electronics, these can be easily replaced with the minimum
downtime.
You MUST disconnect or switch off the power supply to the meter when performing these tasks
and observe the waiting time for Hazardous area approved meters.
To make exchanging the components easy, a copy of the Sensor calibration coefficients are
stored in the converter as well. This means tat you can make the changes without re-calibrat-
ing the meter.
Note:
The following functions must only be performed by qualified personnel.
Replacing the Sensor Electronics
• Unscrew the four small screws holding the Sensor Electronics in place (screws at the rear).
• Take care when removing to ensure that the connections are not damaged.
• Retain the the gasket.
• Replace with new sensor electronics, ensuring that the gasket is well positioned and the
connections have mated correctly.
• Do not force the connectors.
• Tighten securely.
• It is recommended that some Loctite or similar compound is used for the screws.
Replacing the Back End
Turn off the power. Unscrew the front lid and use a small screwdriver to prise the retaining
clips that hold the display and remove the two retaining screws. The converter can then be
removed simply by pulling the plastic chassis at the sides. The converter will slide out easily
after disengaging from the backplane PCB.
To insert the new electronics, simply slide the chassis back into the housing, secure with the
screws previously removed and refix the display over the retaining clips.
When the power supply is re-estalished, the measuring system will recognize a hardware
change.
If the Back End is replaced with a compatible version, the display will show Load from backpl.?
Select:
Load all data
• If the converter was replaced with an identical version and it is
compatible
Load sensor data
• If the converter was replaced & data is not compatible.
• Sensor calibration data is loaded from the backplane
• Customer settings are not loaded
Load no data
• Data in converter is used.
• Backplane data is overwritten next time a change is made and
saved.
In the case that the sensor electronic (SE), or primary with SE, or back end (BE) is changed, the
device will notify it during start-up and will go into fatal error state. In such a case the menu
will have different selections, depending on detected situation. The device can detect 3 different
situations:
Note: in some rare cases 2 confirmations are required (e.g.: “SE data invalid” and than “Copy
BE data”) . This should prevent from choosing the wrong selection in the usual situation.
Select the correct option required in menu C.1.6.3