Installation
84
Aastra 470 as of R1.2
syd-0337/1.2 – R1.2 – 11.2011
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-
ternal auxiliary power supply unit only. To ensure that its operation is maintained
even in the event of a mains outage, an external uninterruptible power supply
(UPS) must be used.
Hazard:
Hazard due to heat generation in the event of short-circuits.
The mains power supply connection must be protected with 16 A maxi-
mum.
X
No earth
loops
Communica-
tion server
Socket-outlets
(Main) distribution
board