Karel MS48 - III.11 Filter & Protection Unit

Karel MS48 Installation & Maintenance Guide
Edition 3.2
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62
III.11. FILTER & PROTECTION UNIT
• I
NSTALLATION
:
The FPBASE module has a metal base part, which has two pear holes.
Through these pear holes the FPBASE module can be mounted on the wall.
On the top covers of FPBASE and FPEXP modules there are four holes, one at
each corner. These holes are used to fix the modules to the ones underneath.
Three holes on FPEXP are connected to FPBASE unit with plastic holders
whereas the fourth one has brass card holder with two washers to carry the
chassis ground to the upper modules.
The following figure illustrates the installation of FPEXP on top of an FPBASE.
Figure B-31
• C
ABLING
:
During the installation of FPBASE and FPEXP units, it is very important to
connect the ground of all the units to the chassis ground of the system. For that
there is a special connector on the metal base of FPBASE, which is to be
attached to the chassis ground of the system through the ground pin at the
down left corner of the system cabinet, to which the ground wire of the mains
cable is connected. This ground is carried to the FPEXP units by way of the
two washers and a brass card holder (see Figure B-32).
It should be noted that the directions of the line / extension connections are
also important. The system side of the card is marked with “PABX" and the
external line (or far extensions) side is marked with “PTT" on the card (see the
following figure).