3Com 4007, Implementation Manual, Page: 113 / 684

Load-Sharing Power Supplies 113
Software-driven power management also provides protection against
the possibility of a catastrophic power failure. If the chassis is
operating in power non-fault-tolerant mode and a power supply fails,
installed EMEs power off selected (low power class) modules until the
power deficit is corrected. Intelligent Power Management ensures that
key components and resources continue to operate, even under
extreme failure conditions.
(Alerts and traps about changes are sent to the network management
applications.)
Load-Sharing
Power Supplies
When you determine the total power budget in your system, consider the
system overhead . System overhead includes power that the chassis itself
and its components (fans, backplane signalling, and the EME) consume.
Calculate the total power requirements for all installed modules before
you install any new module in the chassis. To determine each new
module’s power requirements, see the documentation that is supplied
with each module.
Table 26 lists the system overhead for the chassis.
V = volts; W= watts
This section describes available power modes and power supply capacity
in each power mode. The chassis runs in either of two power supply
output modes:
■
Power Non-Fault-Tolerant Mode
■
Power Fault-Tolerant Mode
Table 26 System Overhead in the Chassis
+5 V +3.5 V +12 V -12 V -5 V +2 V
7-slot chassis 29 W 0 W 49 W 0 W 0 W 4 W