Avaya Definity SI, Maintenance Manual, Page: 66 / 2968

Circuit Packs and Power
555-233-123 2-4 Issue 4 May 2002
The SPE control cabinet has a battery that furnishes power to the processor
memory complex for a minimum of two minutes if the battery is fully charged. This
battery is recharged after power is restored, but the charging process is not
monitored by the system. The cabinet is not able to detect AC power loss, and it
notices only a DC power output failure as the power supply output decays.
The memory contents are preserved, and the processor continues operating
during the two minute period. However, the tone-clock circuit pack is not held
over, and as a result, no connections are possible. The battery does not supply all
the voltages necessary for the internal modem circuit on the processor circuit
pack. As a result, no call is originated to INADS, and the switch cannot answer
any calls. Thus, the switch cannot report any internal or external alarms during
this period. After two minutes (depending on the condition of the battery), the
processor and memory are lost, and the system is totally inactive.
If power is restored in less than 250 milliseconds, no calls are dropped. If power is
restored between 250 milliseconds and two minutes, all calls are dropped, and
memory is maintained. However, since the tone-clock was lost, the system
undergoes a reset once the AC restoral process clears all calls and the alarm log
(in which errors are retained). The switch keeps a record of the restart in the error
log, but it might not detect a power error if the outage is between 1/4 of a second
and one minute, during which time only a loss of clock and not a loss of the power
failure that caused the loss of clock is logged. After one minute, a power error is
logged. If the outage exceeds the battery holdover interval, the error logs and
alarm logs are lost (since they cannot be saved to tape). Depending on the size of
the system, it can take up to one minute to restore service to the ports. After a
power outage of two minutes following the restoral of AC power, the system
re-initializes from the tape. It takes about 10 minutes to restore service. Again, if
the customer has frequent power outages or critical service needs, an external
UPS or DC power system should be considered.
NOTE:
For more power control information, refer to AC-POWER, DC-POWER, and
POWER maintenance objects.