Connecting A Redundant Power Supply To Your Switch 4500 Pwr - 3Com 4500 Getting Started Manual

22 C 2: I
HAPTER NSTALLING THE
Connecting a
Redundant Power
Supply to your Switch
4500 PWR
S
WITCH
The Switch 4500 PWR 26 and 50 port have a -48V DC Redundant Power Supply
socket that can be used in addition to the standard AC connection of the switch.
If you intend to use this DC connection, please read this section.
WARNING: The installation of the Redundant Power Supply (RPS) should only be
carried out by properly trained and qualified personnel.
WARNING: These instructions must be read in conjunction with the RPS flyer and
the safety and installation instructions supplied with your RPS.
WARNING: When powering any Switch 4500 PWR from an RPS, the unit must be
earthed (grounded). This can be achieved by either connecting the power cord to
the unit or by connecting the earth terminal on the rear of the unit to a reliable
electrical earth, or by connecting both. You must ensure that the earth connection
is made before connecting the DC supply from the RPS.
3Com Switches which support -48V DC RPS inputs, that are PoE enabled, can only
be powered by an RPS which complies with the isolation requirements of IEEE-Std
802.3af. Non PoE enabled switches do not have this restriction.
WARNING: A standard 'positive-earthed' -48V redundant power system suitable
for use with telecommunications equipment should not be used with the 3Com
Power-over-Ethernet (PoE) network switches. In order to meet the IEEE 802.3af
(PoE) specification, the -48V output must be isolated from earth (ground) and
meet the isolation requirements in that specification.