3-13
Cisco 3700 Series Routers Hardware Installation Guide
OL-2180-08
Chapter 3 Installing the Router
Power Connections
DC Wiring Requirements for Cisco 3725 Routers
Warning
This product relies on the building’s installation for short-circuit (overcurrent) protection. Ensure that
the protective device is rated not greater than:
15A, 60VDC.
Statement
1005
Caution
Dual sources with opposite-polarity grounding damage equipment.
A Cisco 3725 router with a DC-input power supply requires copper wire and crimp-type terminals for
the power connections.
Table 3-1
summarizes the wiring requirements.
Wiring Procedure for Cisco 3725 Routers
To connect a Cisco 3725 router to a DC power source, perform the following steps:
Step 1
Remove power from the DC circuit. To ensure that power is removed from the DC circuit, locate the
circuit breaker for the DC circuit, switch the circuit breaker to the OFF position, and tape the
circuit-breaker switch in the OFF position.
Tip
Secure all power cabling when installing this unit to avoid disturbing field-wiring connections.
Step 2
Strip the wires to the appropriate length for the terminals. The strip length is 1/8 to 3/16 inch (3 to 5 mm)
for Molex number 19193-0009 and for AMP number 324159-0 terminals.
Step 3
Crimp the terminals to the power input and safety ground wires.
Warning
When stranded wiring is required, use approved wiring terminations, such as closed-loop or
spade-type with upturned lugs. These terminations should be the appropriate size for the wires and
should clamp both the insulation and conductor.
Statement
1002
Step 4
Remove the plastic cover from the terminal block. Save it for reinstallation after you finish wiring.
Step 5
Connect the DC power input wires to the terminal block as shown in
Figure 3-16
. To avoid interference
with the on/off switch, organize the wires downward from the terminal block.
Table 3-1
DC Wiring Requirements for Cisco 3725 Routers
DC Power
Source
DC Input
DC Input
Wire Size
Safety Ground
Wire Size
Wire Terminal (Lug)
Overcurrent
Protection
Nominal 24/48
VDC
1
1.
The input voltage tolerance limits for DC power are 18 and 72 VDC.
24–36 VDC, 9 A, positive or
negative, single source or dual
sources
AWG 18
(1.0 mm
2
)
AWG 14
(2.0 mm
2
)
Molex part number
19193-0017, or equivalent
15 A
maximum
36–60 VDC, 4 A, positive or
negative, single source or dual
sources
AWG 18
(1.0 mm
2
)
AWG 14
(2.0 mm
2
)
Molex part number
19193-0017, or equivalent
15 A
maximum
