Power Interruptions
Issue 1 May 2002
1-9555-233-143
Effects of Power Interruptions
Power holdover is controlled by software in the above manner in order to allow the
system to sustain multiple brief power interruptions without exhausting the
batteries before they have time to recharge. After power is restored, the batteries
are recharged by a circuit that monitors current and time. If the batteries take
more than 30 hours to recharge, a minor alarm is raised, indicating that the
batteries must be replaced or the charger replaced.
The 397 Battery Charger Circuit immediately detects loss of AC power and raises
a warning alarm against AC-POWER that is not reported to the Avaya alarm
receiver system. Certain maintenance objects (MOs) such as external DS1 timing
will report major alarms in this situation. When power is restored, the AC-POWER
alarm is resolved.
External Alarm Leads
Each cabinet provides two leads for one major and one minor alarm contact
closure that can be connected to external equipment. These are located on the
Maintenance circuit packs. If the switch is under warranty or a maintenance
agreement, EXT-DEV alarms are generated by the equipment connected to these
leads and reported to the Avaya alarm receiving system. These may be used to
report failures of UPSs or battery reserves powering the switch. They are also
commonly used to monitor adjuncts such as AUDIX.
Table 1-2. Nominal Power Holdover
Cabinet Administration
Control Carrier
Holdover Duration
Entire Cabinet
Holdover Duration
a-carrier-only 10 minutes 15 seconds
all-carriers
1
1. The cabinet should be administered to all-carriers only if the EPN maintenance board is a
TN775D V2 or greater. However, since it is possible to administer the cabinet to all-carriers
before there is connectivity to the EPN maintenance board, the administration may be
incorrect. To verify whether your cabinet administration is correct, run test maintenance UU
(where UU is the cabinet number). If it is incorrectly administered to all-carriers, a warning
alarm will be issued and you should re-administer the cabinet to a-carrier-only.
2 minutes 2 minutes
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