3com Switch 4500 PWR 50-Port ユーザーズマニュアル

Connecting a Redundant Power Supply to your Switch 4500 PWR

Table 6 Switch Power Inputs

Specifying the

Redundant Power

System

3Com’s redundant power solution allows the use of any off-the-shelf
-48V DC RPS that meets the requirements defined in Appendix B on
page 91.

For an approved vendor list, more details about purchasing the 3Com
recommended RPS and a full set of requirements go to:

http://www.3Com.com/RPS

The 3Com recommended RPS generates -48V DC power using power
supply units (or rectifiers). The outputs of the rectifier(s) are connected
together so that the total -48V power available can be increased by
adding additional rectifiers. For example, three 1500W rectifiers can
provide up to 4500W. Hot removal or insertion of a rectifier will not affect
the -48V DC output voltage.

Table 7 shows an example of the total power available from a number of
1500W rectifiers.

A minimum of two rectifiers are required for each shelf to provide N+1
rectifier redundancy.

Power Input before
User Intervention

Power Input after
User Intervention

Correct Response

AC mains and RPS

RPS only

The unit remains powered by the RPS.

AC mains and RPS

AC mains only

The unit is powered by the AC mains.

PoE dropped on all ports, however
the unit does not reset. PoE restarts
powered by the remaining power
from the AC mains. PoE ports will be
dropped depending on their preset
priority level.

The total power available to the
Switch may be less than when
powered from the RPS. Some PoE
ports may be dropped as they are
unable to obtain the power they
require.

RPS only

AC mains and RPS

The unit remains powered by the RPS.

AC mains

AC mains and RPS