Alcatel-Lucent 7450 ESS-7, Руководство по установке

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7450 ESS-7 Overview
7450 ESS-7 Page 27
C
HASSIS
C
OMPONENTS
The 7450 ESS-7 chassis contains the following components:
• Power Supplies and Redundancy on page 27
→
DC Power Entry Modules on page 27
→
AC Power Entry Modules on page 30
• Fan Trays on page 31
• Air Filter on page 33
• Blank Panels on page 33
P
OWER
S
UPPLIES AND
R
EDUNDANCY
The 7450 ESS-7 chassis is designed to accommodate swappable, load-sharing power modules
(
Figure 8 ). One DC PEM or the combination of one AC power supply module (PSM) and AC
power entry module (PEM) can support the full system current requirements if you are operating
the 7450 ESS-7 without power redundancy. The PSM is also referred to as an AC-to-DC power
converter. For redundancy, two DC PEMs
or the combination of two PSMs (for AC-to-DC power
conversion) and two AC PEMs must be installed and powered on at all times.
DC P
OWER
E
NTRY
M
ODULES
DC PEMs ( Figure 6 ) are easily installed and removed from the rear of the 7450 ESS-7 chassis. DC
modules are installed in power bays 1 and 2. One PEM can support the full system current
requirements if you are operating the 7450 ESS-7 without power redundancy. For redundancy, two
PEMs must be installed and powered on at all times.
Always operate an energized chassis with the safety cover installed over the DC power terminal
block to prevent contact with hazardous voltages and currents and to prevent accidental removal.
DC power cables are not shipped with each PEM. Verify the power cable is compliant with your
local safety codes. PEMs are packaged and shipped separately. Refer to
Preparing the Power Cable
on page 68 for requirements and information to preparing cables.
PEMs have no field replaceable parts. The entire unit must be replaced in the event of a failure.