3-18
Cisco 3700 Series Routers Hardware Installation Guide
OL-2180-08
Chapter 3 Installing the Router
Power Connections
DC Wiring Requirements for Cisco 3745 Routers
A Cisco 3745 router with a DC-input power supply requires copper wire for the power connections.
Table 3-2
summarizes the wiring requirements.
Note
Two types of DC input power supply can be installed in a Cisco 3745 router: power supplies rated at
24/48 VDC nominal input, and power supplies rated at 48 VDC nominal input.
Table 3-2
summarizes
the wiring requirement for both power supplies.
Wiring Procedure for DC Input
To connect the 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 19073-0009 terminals and for AMP/Tyco number 52961 terminals.
Step 3
Crimp the terminals onto the DC power input wires.
Table 3-2
DC Wiring Requirements for Cisco 3745 Routers
Installed Power Supply
DC Input
DC Input Wire
Size
Safety Ground
Wire Size
Wire Terminal (Lug)
Overcurrent
Protection
Nominal 24/48 VDC
1
Identified by the following printed
label:
1.
The input voltage tolerance limits for nominal 24/48-V power supplies are 18 and 72 VDC.
24–36 V,
15 A
AWG 12
(3.0 mm
2
)
AWG 12
(3.0 mm
2
),
minimum
Amp/Tyco No.
52961 or equivalent
20 A
maximum
36–60 V,
7 A
AWG 12 or 14
(3.0 or 2.0 mm
2
)
AWG 12
(3.0 mm
2
),
minimum
For AWG 12:
Amp/Tyco No.
52961 or equivalent
For AWG 14: Molex
No. 19099-0017 or
equivalent
20 A
maximum
Nominal 48 VDC
2
Identified by the following printed
label:
2.
The input voltage tolerance limits for nominal 48-V power supplies are 38 and 72 VDC.
48–60 V,
10 A
AWG 14 or 16
(2.0 or 1.2 mm
2
)
AWG 14
(2.0 mm
2
),
minimum
For AWG 14 or 16:
Molex No.
19099-0017 or
equivalent
20 A
maximum
100-240V 50/60Hz 10A
OR Input +/- 24-36 V 15 A
36-60 V 7 A
!
CISCO 3745
~
100-240V 50/60Hz, 10A
OR 48-60V , 10A
!
CISCO 3745
~
