KROHNE UFM 3030 EEx EN - Manual (Page 27)

UFM 3030 27
5.3 Replacement of electronics unit
Refer to the standard installation and operating instructions for detailed information about resetting
and reprogramming the new electronics unit after replacement. Important customer specific data
(like the value of the internal totaliser) should be noted before replacing the UFC 030…-EEx
electronics unit !
Before commencing work, note the “Before opening” instructions, then continue as follows:
1)
2)
3)
4)
5)
6) Remove the cover of the electronics compartment.
Unscrew the two screws A of the display unit and turn display unit carefully aside or remove
the unit completely by taking out the flat cable connector.
Unscrew the two mounting screws B of the electronics unit as well as screw C, which fixes the
copper earth strip at the back of the housing. A screwdriver with a long shaft (200 mm) can
best be used to unscrew C (e.g. screwdriver type Philips No. 2).
Carefully pull the electronics unit slightly out of the converter housing, until the SMB
connectors of the coaxial cables can easily be unplugged. Then remove the complete
electronics unit from the housing.
Carefully insert the new electronics unit until the numbered SMB connectors can be
connected to the corresponding numbered SMB receptacles on the electronics unit. Then
mount the unit completely into the housing and fix the screws. First C, then B and finally screw
the display unit on the electronics via screws A, after the flat cable connector is connected.
Screw the cover of the electronics compartment back into the housing.
Note the “After opening" instructions during reassembling.
Carefully keep the coaxial cables to the side of the housing, while inserting the
electronics unit into respectively removing it from the converter housing. This is to
prevent damaging of the coaxial cables!
5.4 Replacement of mains fuse and analogue input fuses
Before commencing work, note the “Before opening” instructions, then continue as follows:
1)
2)
3)
4)
Remove the cover of the electronics compartment.
Unscrew the two screws A of the display unit and turn the display unit carefully aside.
The fuse-holder, in which the mains fuse in accordance with IEC 127-2 size Ø5 x 20 mm is
mounted, is now accessible to replace the defect power fuse by a new fuse with the same
rating. The 100…240 V AC power supply (see figure 7 on the next page) is provided with a
fuse rated at T 0.8 A / 250 V, the 24 V AC/DC power supply has a fuse of T 1.25 A / 250 V
(see figure 8). The analogue input circuit A1 is protected by a sub-miniature fuse of type TR 5
that are rated T 50 mA / 250 V according to IEC 127-3 publication. The MODIS versions have
the same power fuses and locations as the standard (non-MODIS) versions, but they do not
have analogue input fuses.
Reassemble the unit in reverse order (points 2 and 1).
Note the “After opening" instructions during reassembling.