KROHNE CORIMASS E P MFM 2081 EEx EN - Manual (Page 5)

Additional Instruction for Ex version MFM 2081 / 3081 5
For both cases the required waiting time between switching off the electronics and opening
the housing has to be considered. The waiting time is mentioned on the data plate of the
system and amounts to 25 minutes for T6 and 10 minutes for T5.
The Ex protection of the system is not valid if the electronics housing is not closed securely.
Make sure after opening the converter housing, to close it fully with the enclosed wrench.
The programming of the converter may also be performed with a closed lid by using the
supplied magnet. Three magnet sensors are assembled on the display board, which allow
the user to operate the converter without touching the display itself.
KROHNE MFC 081
Fig. 1: Converter
After opening the converter housing as described above, one of the following operations
may be performed by the local KROHNE service engineer :
•
Replace supply fuse F9
•
Changing electronics
•
Changing supply voltage setting
•
Changing EPROM’s
These operations are to be performed in an identical manner to the standard converter.
(Please refer to the standard operation manual). Make sure the correct mains fuse (right
value, ceramic body, 1500A breaking capacity) and the corresponding fuse label on the
fuse housing is used. Fuses and labels may be ordered from KROHNE.
Using wrong fuses violates the Ex approval and may damage the system. The earthing
metal sheet of the electronic must be fastened firmly with the screw onto the converter
housing!
The converter should be ‘high pot’ tested according to a specific procedure. Therefore, it is
not permitted to change output modules or any other hardware components (except the list
mentioned above by the local service engineer) without repeating the ‘high pot’ test.
Please contact KROHNE for advice.
1.3 Installation of MFM 2081 / MFM 3081 EEx
In order to get the highest possible accuracy, the user is advised to carry out the pipework
installation as described in the standard manual.