Cisco Systems 3700 Series manual DC Wiring Requirements for Cisco 3745 Routers, 3-18

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 3-2summarizes 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 3-2summarizes the wiring requirement for both power supplies.

Table 3-2	DC Wiring Requirements for Cisco 3745 Routers
						DC Input Wire	Safety Ground		Overcurrent
Installed Power Supply					DC Input	Size	Wire Size	Wire Terminal (Lug)	Protection
Nominal 24/48 VDC1					24–36 V,	AWG 12	AWG 12	Amp/Tyco No.	20 A
Identified by the following printed					15 A	(3.0 mm2)	(3.0 mm2),	52961 or equivalent	maximum
							minimum
label:
					36–60 V,	AWG 12 or 14	AWG 12	For AWG 12:	20 A
CISCO 3745					7 A	(3.0 or 2.0 mm2)	(3.0 mm2),	Amp/Tyco No.	maximum
							minimum	52961 or equivalent
100-240V~50/60Hz 10A				!
OR Input +/- 24-36 V			15 A					For AWG 14: Molex
36-60 V			7 A
								No. 19099-0017 or
								equivalent
Nominal 48 VDC2					48–60 V,	AWG 14 or 16	AWG 14	For AWG 14 or 16:	20 A
Identified by the following printed					10 A	(2.0 or 1.2 mm2)	(2.0 mm2),	Molex No.	maximum
							minimum	19099-0017 or
label:
								equivalent
CISCO 3745				!
100-240V~50/60Hz, 10A
OR 48-60V		, 10A

1.The input voltage tolerance limits for nominal 24/48-V power supplies are 18 and 72 VDC.

2.The input voltage tolerance limits for nominal 48-V power supplies are 38 and 72 VDC.

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.

Cisco 3700 Series Routers Hardware Installation Guide

3-18 OL-2180-08