Fixed Configuration Dc Input Power And Ground Cables - Cisco CRS-1 Site Planning Manual

DC Power Systems

Fixed Configuration DC Input Power and Ground Cables

Each PDU has three pairs of double-stud terminals (RTN, –48V/–60V) for connecting DC input power.
To provide 2N power redundancy, one PDU should be connected to the central office "A" power bus and
the other PDU should be connected to the "B" power bus.
The requirements for the DC input power and ground connections are as follows:
•
Figure 2-2
0.60
.10
Cisco CRS Carrier Routing System 8-Slot Line Card Chassis Site Planning Guide
2-6
For DC input power cables, select the appropriate wire gauge based on the National Electrical
Code (NEC) and local codes for 60-amp service at nominal DC input voltage (–48/–60 VDC).
Three pairs of cable leads, source DC (–) and source DC return (+), are required for each PDU.
These cables are available from any commercial cable vendor. All input power cables for the chassis
should have the same wire gauge and cable lengths should match within 10 percent of deviation.
Each DC input power cable is terminated at the PDU by a cable lug. The cable lugs must be
dual-hole, and have a 45-degree angle tongue. They must be able to fit over 1/4-inch terminal studs
at 0.625-inch (15.88-mm) centers. For example, you could terminate a 2-AWG power cable with a
cable lug, such as Panduit part number LCC2-14AWH-Q (Cisco part number 32-0677-01) or
equivalent, as shown in Figure
Note Use local electrical codes for clearance requirements when using power lugs to ensure safe
operation.
DC Input Power Cable Lug
All measurements in inches
2.38
Ø 0.27
2 holes
0.25 0.63 0.38
1.16
2.38
2-2.
1.44
45˚
Chapter 2 Power and Cooling
OL-5802-09