Mitel Aastra 470 System Manual page 135

Automatic detection of critical power supply situations
Only Aastra 5360, and phones of the Office series:
When a system phone (or a second such phone) is connected to the DSI bus, the
maximum power input is automatically determined; all the system phones (incl. ex-
pansion key module and alphanumerical keyboard) connected to the interface are
taken into account. The maximum power available is also determined based on the
calculated line length (assumption: Diameter = 0.5 mm). If the calculated power
available is below the maximum possible power input of the connected system
phones, the message
nected last (accuracy approx.150 m).
System phones Aastra 5361, Aastra 5370 and Aastra 5380 only:
During start-up, these system phones carry out a detailed measurement of the
available power. A warning is shown on the display if the result is inadequate:
power too weak: External power supply required!
Notes
– Depending on the power available based on the line length on the
DSI-AD2 bus the ringing and hands-free volume decreases accord-
ingly.
– The backlighting of the Aastra 5380 display is brighter if the phone is
powered by a power supply unit.
Rating examples
Example 1:
Aastra 5370
Maximum power requirements as per
Fig. 47 indicates:
• Maximum line length for a wire diameter of 0,4 mm: 840 m
• Maximum line length for a wire diameter of 0,5 mm: 1200 m
• Maximum line length for a wire diameter of 0,6 mm: 1200 m
Example 2:
An Aastra 5380 with 2 Aastra M530 expansion key modules
Power requirements as per
Fig. 47 indicates:
• Maximum line length for a wire diameter of 0,4 mm: 520 m
Aastra 470 as of R3.2
syd-0337/1.6 – R3.2 – 09.2014
Power supply critical xy m
Tab.
Tab. 60: 1340 + 300 + 300 = 1940 mW.
is generated on the phones con-
60: 1220 mW
Installation
Line
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