Installation
100
Aastra 470 as of R3.2
syd-0337/1.6 – R3.2 – 09.2014
Note
In the case of an indirection connection make sure that the communica-
tion server’s earthing wire does not form any earth loops with the
earthed cable screenings of the installation cables leading up to the
(main) distribution frame. The cables should be kept as short as possible
and laid out in parallel.
4. 3. 2
Connecting the cable screening
When using shielded installation cables also use shielded RJ45 connectors. In this
way the shielding of the installation cables is automatically connected with the
housing of the communication server and therefore with the building earth.
Note
Connect the cable screens to one another at the splitting point only.
Observe the tree structure principle to prevent earth loops.
Fig. 23
Tree structure principle
4. 4
Powering the communication server
The communications server is powered as standard with 230 VAC or 115 VAC di-
rectly from the mains. The internal power supply unit (PSU2U) is rated for the
power requirements of a typical system expansion. The external auxiliary power
supply unit APS2 can be used to increase the power supply available or to increase
operating reliability (redundancy in the event of a failure on the part of one of the
two power supplies). The communication server can also be operated with the ex-
X
No earth
loops
Communica-
tion server
Socket-outlets
(Main) distribution
board