Nebs Supplemental Unit Bonding And Grounding Guidelines - Cisco ASR 9000 Series Installation Manual

NEBS Supplemental Unit Bonding and Grounding Guidelines

NEBS Supplemental Unit Bonding and Grounding Guidelines
The router is sensitive to variations in voltage supplied by the power sources. Overvoltage, undervoltage, and
transients (or spikes) can erase data from memory or cause components to fail. To protect against these types
of problems, ensure that there is an earth-ground connection for the router. You can connect the grounding
pad on the router either directly to the earth-ground connection or to a fully bonded and grounded rack.
When you properly install the chassis in a grounded rack, the router is grounded because it has a metal-to-metal
connection to the rack. Alternatively, you can ground the chassis by using a customer-supplied grounding
cable that meets your local and national installation requirements (we recommend 6-AWG wire for U.S.
installations). One end of the grounding cable is connected to the chassis with a grounding receptacle (provided
in the router accessory kit) and the other end to the appropriate grounding point at your site.
Although the router chassis requires a safety earth ground connection as part of the power cabling to power
modules, you must permanently connect the central office ground system or interior equipment grounding
system to one of the three supplemental bonding and grounding connections on the back or side of the router
chassis to meet Network Equipment Building System (NEBS) requirements as well as safety compliance
requirements. These grounding points are referred to as the NEBS bonding and grounding points.
Note
You automatically ground the chassis with AC power modules when you connect them to AC power sources.
However, it is still strongly recommended to provide an additional direct earth-ground connection for the
chassis.
For DC power supplies, it is mandatory to connect a grounding wire when wiring the power supply to the DC
power source.
Figure 55: NEBS Bonding and Grounding Points on the Cisco ASR 9006 Router Chassis
1 NEBS grounding
point on right side of
the chassis
Cisco ASR 9000 Series Aggregation Services Router Hardware Installation Guide
44
2 NEBS grounding
point on rear of the
chassis
Preparing for Installation
3 NEBS grounding
point on left side of
the chassis