KROHNE ALTOSONIC III EN - Manual (Page 34)

ALTOSONIC III 34
7.3 Replacement of
electronics unit
Refer to the instructions for information about resetting and reprogramming the new electronics unit after replacement.
Important application specific should be noted before replacing the UFC III…-EEx electronics unit!
Before commencing work, note the “Before opening” instructions, then continue as follows:
• 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!
7.4 Replacement of
mains fuse
Before commencing work, note the “Before opening” instructions, then continue as follows:
• 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 below) 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 below).
• Reassemble the unit in reverse order.
Note the “After opening" instructions during reassembling.
Power supply PCB - 100…240 V AC Power supply PCB - 24 V AC/DC