Power Fail; Pstn; Isdn - BT Inspiration Installation & Maintenance Manual

Power fail

When planning the extension wiring for the system, consideration should be given to the use and location of
Featurephones and two wire extensions where they may be used in power fails situations.

PSTN

In the event of a total system power failure at least 50% of the equipped lines are switched to extensions.
Lines 1 and 2 are power failed to extensions 24 and 25 the last two extensions on the basic unit. Line 5 is
power failed to extension 31 and Line 7 to extension 37, the last extensions on each of the expansion boards.
NOTE:
If lines are power failed to extension positions equipped with Featurephones the user must replace the
Featurephone with a standard two-wire phone to answer or make calls. FEATUREPHONES CANNOT BE
USED IN POWER FAIL
Line Position
Line 1
Line 2
Line 5
Line 7
Each board with PSTN exchange line capability is equipped with a power fail circuit path

ISDN

In the event of a total system failure, the ISDN lines will not operate. ISDN devices can be connected
directly to the ISDN NTE or the SO bus, and work independently of the system.
Power fail extension
Extn.24
Extn 25
Extn.31
Extn 37
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