3Com 3CR17251-91 - Switch 5500G-EI Stackable Gigabit Ethernet Getting Started Manual - page 37
Connecting a Redundant Power Supply
37
3Com’s RPS solution uses -48V DC power distribution. The RPS system
provides bulk -48V DC power that is separately distributed to a number
of network switches.
Each RPS consists of a shelf which can house from one to six rectifiers, a
Distribution Module and a Management Module.
Connecting the
Switch to the
Redundant Power
System
When connecting the RPS to the Switch, the circuit breaker and 2-core
cable need to be matched to the power rating of the Switch.
Table 11
shows the recommended circuit breaker and cable rating for the Switch
5500. The recommended cable length should not exceed 3 metres (9.84
feet).
Table 11 Switch 5500 Circuit Breaker and Cable Ratings
WARNING: RPS Manufacturers recommendations must be followed
when connecting the cable to the RPS.
WARNING: Ensure that the circuit breaker in the RPS is in the open (off)
position when connecting the cable to the RPS and the cable and
connector to the Switch.
WARNING: You must ensure that the positive terminal on the Switch is
connected to the positive (common) terminal of the RPS and that the
negative terminal on the Switch is connected to the negative (circuit
breaker) terminal of the RPS..
Figure 14
shows how to connect the power supply to the RPS socket in
the back of the Switch. Use the cable tie supplied with your Switch to
support the cable at the rear of the RPS connector as shown.
Circuit Breaker Minimum 2-Core Cable Diameter
Non PoE
6A C type
18 AWG (solid or stranded cable)
PoE
25A C type
12 AWG (solid or stranded cable
)