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Cisco CRS-1 Carrier Routing System 8-Slot Line Card Chassis Site Planning Guide
OL-5802-06
Chapter 2 Power and Cooling
Supplemental Bonding and Grounding
Supplemental Bonding and Grounding
The 8-slot line card chassis has a safety earth ground connection as part of the power cabling to the
PDUs. The chassis also has supplemental bonding and grounding points (two threaded ground inserts)
that you can use to connect the router to the central office ground system or interior equipment grounding
system. Also referred to as the network equipment building system (NEBS) bonding and grounding stud,
these grounding points are located at the rear (MSC side) of the chassis (see
Figure 2-8).
Note The NEBS bonding and grounding points are intended to satisfy the Telcordia NEBS requirements for
supplemental bonding and grounding connections. If you are not installing the router in a NEBS
environment, you can skip these guidelines and rely on the safety earth ground connection for the PDUs.
Figure 2-8 NEBS Bonding and Grounding Points (Rear of Chassis)
To connect the chassis to a supplemental ground connection, you must have the following:
• A grounding lug that has two M6 bolt holes with 0.625- to 0.75-inch (15.86- to 19.05-mm) spacing
between them, and a wire receptacle large enough to accept a 6-AWG or larger multistrand copper
wire. The lug is not available from Cisco Systems; it is available from electrical-connector vendors.
• Two M6 or equivalent hex-head bolts with locking washers and nuts (nickel-plated brass is ideal).
These bolts, locking washers, and nuts are not available from Cisco Systems; they are available from
any commercial hardware vendor.
• A grounding wire. Although we recommend at least 6-AWG multistrand copper wire, the actual
wire diameter and length depend on your router location and site environment. This wire is not
available from Cisco Systems; it is available from any commercial cable vendor.
Caution The DC Return of the Cisco CRS-1 8-slot chassis should remain isolated from the system frame and
chassis (DC-I: Isolated DC Return).
For additional information about NEBS, see Cisco CRS-1 Carrier Routing System Regulatory
Compliance and Safety Information.
1 NEBS bonding and grounding points
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