Establishing the System Ground
This section describes how to connect a system ground to the Catalyst 6880-X switch.
Installations that rely solely on system grounding using only an AC third-prong ground run a substantially
greater risk of equipment problems and data corruption than those installations that use both the AC
third-prong ground and a properly installed system ground.
Caution
The system ground provides additional grounding for EMI shielding requirements and grounding for the low
voltage supplies (DC-DC converters) on the modules. You must observe the following system grounding
guidelines for your chassis:
•
You must install the system ground connection with any other rack or system power ground connections
that you make. The system ground connection is required if FXS modules are installed or if this equipment
is installed in a U.S. or European Central Office.
•
You must connect both the system ground connection and the power supply ground connection to an
earth ground. The system ground connection is required if FXS modules are installed or if this equipment
is installed in a U.S. or European Central Office.
•
When using DC-input power supplies, you must install the system (ground before you attach the source
DC power cables to the DC PEM. Power down the chassis before attaching the system ground.
In all situations, grounding practices must comply with Section 250 of the National Electric Code (NEC)
requirements or local laws and regulations. A 6 AWG grounding wire is preferred from the chassis to the
rack ground or directly to the common bonding network (CBN). The equipment rack should also be
connected to the CBN with 6 AWG grounding wire.
Note
The system ground serves as the primary safety ground for chassis that are equipped with DC-input power
supplies. The DC-input power supplies for these chassis do not have a separate ground.
Note
Required Tools and Equipment
To connect the system ground, you need the following tools and materials:
• Grounding lug—A two-hole standard barrel lug. Supports up to 6 AWG wire. Supplied as part of
accessory kit.
• Grounding screws—Two M4 x 8 mm (metric) pan-head screws. Supplied as part of the accessory kit.
• Grounding wire—Not supplied as part of accessory kit. The grounding wire should be sized according
to local and national installation requirements. Depending on the power supply and system, a 12 AWG
to 6 AWG copper conductor is required for U.S. installations. Commercially available 6 AWG wire is
recommended. The length of the grounding wire depends on the proximity of the switch to proper
grounding facilities.
•
No. 1 Phillips screwdriver.
Catalyst 6880-X Switch Hardware Installation Guide
OL-30827-02 45
Installing the Switch
Establishing the System Ground