Opac Battery Backup System - Nortel DMS-100 Series Maintenance Manual

2-28 OPAC maintenance overview

OPAC battery backup system

The OPAC provides up to six strings (three pairs) of batteries for backup
power when an ac failure occurs. The amount of backup time the OPAC
provides depends on the following causes:
The OPAC contains Eagle-Picher 6 V batteries. The following are the
estimated battery backup times for the OPAC:
297-8211-550 Standard 05.01 August 1999
alarm detection and automatic battery switching when OMPES detects
these conditions:
— ac power failure
— BCC fuse 0 or 1 failure
— rectifier 0 or 1 failure
— high temperature (EHT)
log reports that record the changing events or failures that the OMPES
system encounters
one audit each hour in the OPMPES to confirm the condition of the
OPMPES as viewed by the software
Note: The batteries are set to a software state. The software state of the
PES alarms is set to the hardware state of the OPMPES. When the
detection of a mismatch between software and hardware occurs, the
audit restores the hardware to the current condition of the software. The
audit generates a log message that indicates the action of the audit.
the state of the remote maintenance module (RMM) in the state of the
OPMPES circuits
number of battery strings installed (none, four, or six)
condition of the battery strings
number of line drawers and line cards installed
number of subscriber lines off-hook
length of the subscriber loops
The estimated backup time for OPAC configured for 640 lines is 6.6 h
when equipped with the following:
— ten line drawers and 640 line cards
— six strings (three string pairs) of Eagle-Picher batteries
— a call rate of 3.0 CCS, when 8.3% of lines are off-hook
— maximum of operating company provided equipment is 20 A.