KROHNE UFM 500 ATEX EN - Manual (Page 9)

8
5.1.1 Replacement of electronics unit
See 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 totalizer) should be noted before replacing the
electronics unit !
Before commencing work,
note the instructions in Section 4.1 ("Before opening") .
Then continue as follows:
1. Loosen the interlocking device and remove the cover of the electronics compartment.
2. Unscrew the two screws A (see figure 5 in section 4.1) of the display unit and turn display
unit carefully aside or remove the unit completely by taking out the flat cable connector.
3. Unscrew the two mounting screws B of the electronics unit as well as screw C, which
fixes the brass 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).
4. Pull the electronics unit carefully out of the converter housing, till the SMB connectors of
the coaxial cables can be unplugged easily. Then remove the complete electronics unit
and replace it with a new one.
5. Check on the new electronics unit if the voltage setting (only applicable for AC supplies)
and mains fuse rating are correct. Change the voltage setting (see Section 3.1.3) or
exchange the mains fuse (see Section 3.1.2) if necessary.
6. Carefully insert the electronics unit till 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.
7. Screw the cover of the electronics compartment back into the housing.
Note the instructions of section 4.1 ("After opening") during reassembling.
IMPORTANT !
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 !
5.1.2 Replacement of mains fuse(s)
a) AC versions 115/230 V AC and 100/200 V AC
Before commencing work, note the instructions in Section 4.1 ("Before opening") .
Then continue as follows:
1. Loosen the interlocking device and remove the cover of the electronics compartment.
2. Unscrew the two screws A (see figure 5 in section 4.1) of the display unit and turn the
display unit carefully aside.
3. The fuse-holder, in which the mains fuse in accordance with IEC 127-2 size Ø5 x 20 mm,
(breaking capacity high) is mounted, is now accessible to replace the defect mains fuse
F1 by a new fuse with the same rating. The rating depends on the voltage setting of the
power supply unit. (T200mA for 100 or 115V AC and T125mA for 200 or 230 V AC). See
also the yellow sticker that is glued on the mains transformer as shown in Figure 6 on the
next page.
4. Reassemble the unit in reverse order (points 2 and 1).
Note the instructions of section 4.1 ("After opening") during reassembling.