Connecting The Cable Screening; Powering The Communication Server - Mitel Aastra 470 System Manual

Installation
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.
Communica-
tion server
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-
100
(Main) distribution
board
Socket-outlets
No earth
X
loops
Aastra 470 as of R3.2
syd-0337/1.6 – R3.2 – 09.2014