3com 8814 User Manual

Page of 104
General Architecture
15
Table 2 describes typical equipment configurations and specifications of external 
PoE power system.
The external PoE power system has monitor function. It provides one system 
monitoring module, one RS232 and two RS485 monitoring interfaces. The system 
monitoring module reports the running information of the PSUs in the system to a 
fabric through RS232 or RS485 interface and indicates alarm status by the alarm 
LED (ALM). You can connect cables to the interfaces from the front as well as the 
rear of the frame.
The external PoE power system for the Switch 8800 Family only supports the 
RS485 monitoring interface.
MBUS
Introduction
The MBUS is a service-independent maintenance and test bus. No service traffic 
goes through the MBUS. The shutdown and reset of the MBUS does not affect the 
services on the switch, and faults that have occurred on modules do not affect the 
MBUS.
Through the MBUS, the system instructs the MBUS modules on individual cards to 
power on/off the cards one by one in turn, thus prevent power surging. The MBUS 
module software must support online upgrade.
Table 2   Typical equipment configurations and specifications of external PoE power system
Item 
Description 
Physical dimensions (H x W x D) 
177 x 486 x 320.5 mm (7.0 x 19.1 x 12.6 in.) 
System controller 
One 
Rectifier 
Two NP2500UAC (required) + one redundant 
NP2500UAC (optional) 
AC accessory 
Three AC inputs and switches
Three-phase AC voltage detection circuit
Input voltage range: 90 to 290 VAC; rated voltage 
and current: 250 VAC, 20 A 
DC accessory 
A single DC output, with max output current of 
93 A 
Max power consumption 
4500 W
Table 3   LEDs of external PoE power system
LED 
Label  Color 
Normal 
 
state 
Abnormal 
 
state 
Abnormal reason 
Input power LED 
AC 
Green  ON 
OFF 
Loss of AC input power, or blown 
fuse 
Output power LED 
DC 
Green  ON 
OFF 
No DC output from PSU 
Fault LED 
Fault 
Red 
OFF 
ON 
Irreversible fault occurred in PSU 
Running status LED  RUN 
Green  ON 
OFF 
PSU shutdown or PSU running 
trouble 
Alarm LED 
ALM 
Red 
OFF 
ON 
Loss of AC input power, 
under-voltage or over-voltage 
input, under-voltage or 
over-voltage output, or PSU fault