Cisco 3800 Series - Page 56

Power Connections
26
Connecting Cables to Cisco 3800 Series Routers
OL-5970-02
Note When source A and source B are wired with common negative terminals, as in Figure 17, discharging
does not occur and there is no requirement that source A and source B voltages be equal.
Figure 18 Connecting Source A and Source B with Common Positive Terminals
In Figure 19, source A and source B are wired with opposite polarity grounds. Do not use this
configuration.
Caution Do not use the DC input configuration shown in Figure 19.
A-
A+
B+
B-
Va
Vb
+
+
127040
A-
A+
B+
B-
Va
Vb
+
+
A-
Va voltage = Vb voltage (within 0.25 V)
Va voltage = Vb voltage (greater than 0.25 V)
A+
B+
B-
Va
Vb
+
+