KROHNE CORIMASS G-MFM 4085 EN - Manual (Page 82)

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8. Service and Troubleshooting
8.1 Threads and ”O” Ring of the converter housing lid
The screw threads and gaskets of both housing covers should be well greased at all times.
Always check for signs of damage and never allow dust to accumulate. Defective gaskets and
lids should be replaced immediately to maintain the integrity of the protection category.
The grease used must be non-corrosive to aluminium and should be acid- and resin-free.
8.2 Replacing the converter electronics
Always switch off power before commencing work!
For Ex version allow 30 minutes to cool before opening housing.
1. Use the special wrench to remove the cover from the terminal compartment.
2. Disconnect all cables from the terminals in the rear terminal compartment.:
MFC 085 : term. 5/6/4/4.1/4.2/11/12
3. Use the special wrench to remove the cover from the electronic compartment.
4. Undo screws A and fold display board to side.
5. Remove plug C (10-pin, signal cable).
6. Undo screws D using a screwdriver for recessed-head screws and carefully remove the
complete electronics.
7. On the electronics, check the supply voltage and fuse F9, and change / replace if
necessary, see Sect. 8.3.
8. Reassemble in reverse order (points 6 to 1).
9. Primary head specific parameters, as printed on the data plate, must now be entered on to
the new converter. (see section 7.1).
10. Subsequently be sure to check the zero and store the new zero value.
A. Screws that hold the display
PCB in place.
B. Ribbon cable connecting
display PCB to converter
electronics.
C. 10-pin sensor connector.
D. Screws that hold the
converter electronics in place.
Important: Ensure that the screw thread of the covers on the electronics and terminal
compartments are well greased at all times. The grease used must be non-
corrosive to aluminium and should be acid- and resin-free.
B
C