Nortel Networks NN43021-110 - Manual (Page 49)

Hardware architecture 49
AC power
AC-powered systems require no external power components and can
plug directly into commercial AC (utility) power. AC-powered systems are
especially suitable for applications that do not require reserve power. They
are also recommended systems that require reserve power with backup
times ranging from 15 minutes to 8 hours.
If reserve power is required with an AC-powered system, an Uninterruptible
Power Supply (UPS), along with its associated batteries (either internal or
external to the unit), is installed in series with the AC power source (see
Figure 17 "ExternalAC-power architecture with reserve power" (page 49) ).
An AC-powered system that does not require long-term backup can benefit
from a UPS with short-term backup because the UPS typically provides
power conditioning during normal operation, as well as reserve power
during short outages or blowouts.
Figure 17
ExternalAC-power architecture with reserve power
DC power
DC-powered systems always require external rectifiers to convert
commercial AC power into the standard –48 V DC required within the
system (see
Figure 18 "ExternalDC-power architecture with reserve power"
(page 50) ). Batteries are generally used with DC-powered systems, as
the traditional telecommunications powering method is for the rectifiers to
continuously charge a bank of batteries, while the system power "floats"
in parallel on the battery voltage. However, batteries are only required
if reserve power is needed.
Nortel Communication Server 1000
Communication Server 1000M and Meridian 1 Large System Overview
NN43021-110 01.03 Standard
Release 5.0 18 February 2008
Copyright © 2003-2008, Nortel Networks
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