Establishing the System Ground

This section describes how to connect a system ground to the SAN c-type switch.

Note: This system ground is also referred to as the network equipment building system (NEBS) ground.

Note: You must use the system (NEBS) ground on both AC- and DC-powered systems if you are installing this equipment in a U.S. or European Central Office.

The system (NEBS) ground provides additional grounding for EMI shielding requirements and grounding for the low-voltage supplies (DC-DC converters) on the modules and is intended to satisfy the Telcordia Technologies NEBS requirements for supplemental bonding and grounding connections. You must observe the following system grounding guidelines for your chassis:

You must install the system (NEBS) ground connection with any other rack or system power ground connections that you make. The system ground connection is required if this equipment is installed in a U.S. or European Central Office.

You must connect both the system (NEBS) ground connection and the power supply ground connection to an earth ground. The system (NEBS) ground connection is required if this equipment is installed in a U.S. or European Central Office.

For IBM c-type SAN devices that are equipped with DC-input power supplies, you must install the system (NEBS) ground before you attach the source DC power cables to the DC PEM. If the chassis is powered up, you must power down the chassis before attaching the system (NEBS) ground. If you are installing the system (NEBS) ground on models of the IBM c-type SAN Device chassis that are equipped with either AC-input or DC-input power supplies, you do not need to power down the chassis.

Note: The system (NEBS) ground serves as the primary safety ground for the IBM c-type SAN Directors that are equipped with DC-input PEMs. The DC-input power supplies for these chassis do not have a separate ground.