3Com 3C16895, Руководство по установке

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30 C
HAPTER
1: S
WITCH
7750 C
OMPONENTS
Table 38 describes the specifications of the Switch 7750 power module.
Power Distribution
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 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.
External PoE Power
System
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 26 illustrates the Switch 7750 PoE power system.
Figure 26 Switch 7750 PoE Power Supply
The Switch 7750 supports PoE external input power up to 2400 W.
Table 38 Specifications for Switch 7750 Power Modules
Specification AC Power Module
Input 100 V to 240 V, 47 to 63 Hz, 6 A
Maximum output 350 W