Installation
106
Aastra 470 ab R3.0
syd-0337/1.5 – R3.0 – 05.2013
4. 4. 3 Uninterruptible power supply (UPS)
The use of an external uninterruptible power supply (UPS) guarantees operation 
even in the event of a mains outage.
The UPS battery capacity is rated according to the communication server’s primary 
power requirements and the required bridging time. The table below shows the 
maximum power requirements of the communication server in its maximum con-
figuration and maximum traffic volume for different types of power supply.
Tab. 39 Maximum power requirements of the communication server
The battery capacity required [Ah] can be calculated using the battery voltage and 
the maximum bridging time. It is important to note that the battery must never be 
allowed to become completely discharged and that in typical conditions only ap-
prox. 60% of the maximum power requirements is needed.
Note
The uninterrupted operation of the communication server is ensured if 
the UPS takes over the power supply within 20 ms of the mains outage.
See also
For more technical details see "Technical Data", page 280.
Communication server Maximum power requirements
Internal power supply unit only 210 VA
External auxiliary power supply unit only 400 VA
Internal power supply unit + external auxiliary power sup-
ply unit
610 VA