Owner`s manual

1–9Overview
Power supply modules can be hot swapped while the DEChub 900 MultiSwitch hub
is operating. This feature allows you to remove faulty power supply modules, add
extra power supply modules, or move power supply modules to other slots without
interrupting power or network modules.
If a power supply module fails or is removed from a hub that is not configured for N+1
redundancy, then the hub does not have sufficient power for operation. If this occurs,
then the hub powers down as many full-height network modules as required to bal-
ance the demand for power and the load. Network modules are powered up from
right (slot 8) to left (slot 1) and are powered down from left to right.
The Hub Manager monitors the power system and displays power system messages
in the Hub Status Display. The Hub Manager power display messages that appear
provide you with information on the power system status, and on the amount of
power available in the hub. This information, in addition to the power needs of a net-
work module (from the module label), lets you determine if enough power exists to
install a network module in the hub.
At hub powerup, power is automatically supplied to the chassis, the Hub Manager,
and all half-height network modules. Also at powerup, the Hub Manager calculates
the total power available from the power system. If you install additional power sup-
ply modules in an operational hub, the Hub Manager recalculates the total power
available.
You can install or remove network modules on an operational DEChub 900 Multi-
Switch without having to power down the hub, and without disturbing other network
modules or their configuration.
Refer to Chapter 5 for additional information on the hub power system.