Power Module; Power Distribution; External Poe Power System - 3Com 7754 Installation Manual

Power Module

Power Distribution

External PoE Power
System
Table 43 Specifications for the
Specification
Port transmission speed
Cables and maximum
transmission distance
Compliance
Only one AC power module is required for the 4-slot chassis, although two power
module slots are provided to implement N+1 redundancy.
The 7-slot and 8-slot chassis provides three power module slots to implement N+1
redundancy. However, two power modules are sufficient to power one of these
fully loaded Switch 7700 systems.
The 8-slot chassis offers both AC and DC power modules. Table 44 describes the
specifications of each type of power module.
Table 44 Specifications for AC and DC Power Modules
Specification AC Power Module
Input 100 V to 240 V, 47 to 63 Hz
Maximum output 460 W
The Switch 7750 power distribution box is installed on the chassis floor in the back
of the chassis. It filters, connects, disconnects, and distributes electrical current to
the switch.
The power distribution box for the 4-slot chassis has two inputs and each input
has a separate ON/OFF switch. One input can support the normal operation of one
power module. Both AC inputs must be connected and switched on to provide
power to both power modules and to offer N+1 AC power redundancy. When
two power modules are installed but only one AC power input is working, only
one power module will operate. However, the power module LEDs on the Fabric
display alarm information for the power module that is not working.
The power distribution box for the 7-slot and 8-slot chassis has two inputs and
two ON/OFF switches. One input can support the normal operation of three AC
power modules at the same time. When both AC power inputs are connected and
switched on, the power distribution box offers N+1 AC power redundancy.
The Switch 7750 supports power-over-Ethernet (PoE). When the Switch 7750 is
equipped with an external PoE power system and PoE-capable I/O modules, it can
provide -48 V DC power to remote powered devices (PDs), such as IP phones,
WLAN APs, and network cameras through twisted pair cable.
Figure 30 illustrates the Switch 7750 PoE power system.
8-Port 10/100/1000BASE-T GE
Description
10 Mbps, half/full duplex
100 Mbps, half/full duplex
1000 Mbps, full duplex
4 100-ohm Category-5 non-shielded twisted pairs up to 100
m (300 ft).
IEEE 802.3ab
IEEE802.3
IEEE802.3u
IEEE802.3x
Power Module
Module (continued)
DC Power Module
-48 V to -60 V
460 W
33