Figure 2-4 – Cisco CRS-1 User Manual
Cisco CRS Carrier Routing System 8-Slot Line Card Chassis Site Planning Guide
Chapter 2 Power and Cooling
DC Power Systems
DC input power cables must be connected to the PDU terminal studs in the proper positive
(+) and negative (–) polarity. In some cases, the DC cable leads are labeled, which is a
relatively safe indication of the polarity. However, you must verify the polarity by measuring
the voltage between the DC cable leads. When making the measurement, the positive (+)
lead and the negative (–) lead must always match the (+) and (–) labels on the PDU.
An earth ground cable is required for each fixed configuration DC PDU. We recommend that you
use at least 6-AWG multistrand copper wire. This wire is not available from Cisco Systems; it is
available from commercial cable vendors.
The ground wire cable lug should be dual-hole, as shown in
, and able to fit over M6
terminal studs at 0.625-inch (15.88-mm) centers (for example, Panduit part number LCD6-14A-L
DC Earth Ground Cable Lug
shows the DC input power cables connected to the DC PDU terminal studs.
Fixed Configuration DC PDU Power Cable Connections
All measurements in inches
Each set of cables (RTN and –48V/–60V) is a single VDC input.