Owner`s manual

5–1
5
Hub Power System
The following sections describe the hub power system’s functionality. It also
describes installing and removing power supply modules, and guidelines for calcu-
lating power needs.
Redundant Power
In certain configurations, the hub may need one, two or three power supply modules
to provide power to all the network modules. The addition of an extra power supply
module allows for the failure of any one of these power supply modules. Adding an
extra power supply module to allow for the failure of any one of the power supply
modules, and continually providing sufficient power to all network modules, is
referred to as an N+1 power system.
You can add extra power supply modules beyond N+1, and these will share in deliv-
ering power to the power system and will also provide the power supply system with
additional backup capability.
The Hub Manager allocates a maximum of 420 watts of power to the backplane when
four power supplies are installed so that the fourth power supply can always provide
redundant power.