Bonding and grounding guidelines – Cisco CRS-1 User Manual

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Cisco CRS Carrier Routing System 8-Slot Line Card Chassis Site Planning Guide


Chapter 2 Power and Cooling

Bonding and Grounding Guidelines

General power and grounding requirements are:

Installation of the routing system must follow national and local electrical codes:

In the United States: United States National Fire Protection Association (NFPA) 70 and United
States National Electrical Code (NEC).

In Canada: Canadian Electrical Code, part I, CSA C22.1.

In other countries: International Electrotechnical Commission (IEC) 60364, parts 1 through 7.

Two separate and independent AC or DC power sources are needed to provide 2N redundancy for
system power. Each power source requires its own circuit breaker.

Each power source must provide clean power to the site. If necessary, install a power conditioner.

The site must provide short-circuit (over-current) protection for devices.

Proper grounding is required at the site to ensure that equipment is not damaged by lightning and
power surges. In addition:

For fixed and modular configuration AC-powered systems, a grounding-type AC power outlet
is required. In addition, AC-powered systems also require chassis grounding.

For fixed configuration DC-powered systems, each DC PDU requires a connection to earth

Modular configuration DC-powered systems support chassis grounding only.

When planning the power for the site, be sure to include the power requirements for any external
terminals and test equipment you will use with your system.


Be sure to review the safety warnings in Regulatory Compliance and Safety Information for the Cisco
CRS Carrier Routing System
before attempting to install the routing system.

Bonding and Grounding Guidelines

The router chassis has safety earth ground connections in conjunction with the power cabling to the fixed
configuration PDUs.


Modular configuration power supports chassis grounding only.

The chassis allows you to connect the central office ground system or interior equipment ground system
to the bonding and grounding receptacles on the router chassis, when either a fixed or modular
configuration power system is installed. Six chassis grounding points are provided at the rear (MSC) side
of the chassis, as shown in

Figure 2-1

. Each side of the chassis has one pair of threaded ground studs

located on the inside of the chassis and two pairs of grounding receptacles located on the outside of the
chassis. These ground points are also called the network equipment building system (NEBS) bonding
and grounding points.


These bonding and grounding receptacles satisfy the Telcordia NEBS requirements for bonding and
grounding connections.