Cisco Systems Cisco CRS-1 manual Supplemental Unit Bonding and Grounding Guidelines

Chapter 2 Installing and Removing Power Components

About Installing and Removing the Power Components

Caution A Cisco router must be operated with all its power modules installed at all times for electromagnetic compatibility (EMC).

The Cisco CRS-1 4-slot line card chassis requires that at least the power shelves and their components be installed to operate properly. Two types of power shelves exist: an AC shelf and a DC shelf. An AC power shelf houses AC rectifiers, while a DC power shelf houses the DC power input module (PIM) and DC power input shelf (which encloses the DC power supplies). We recommend that you use only one type of power shelf in a chassis at a time.

Warning This unit might have more than one power supply connection. All connections must be removed to de-energize the unit. Statement 1028

The Cisco CRS-1 4-slot line card chassis is shipped fully populated with a power shelf that contains four power supplies for power redundancy. See the appropriate installation section (see “Installing a DC Power Shelf” section on page 2-11or “Installing an AC Power Shelf” section on page 2-22) for detailed installation information.

As viewed from the front (PLIM) side of the chassis, the left two power supplies feed output A, while the right two power supplies feed output B.

For 2N redundancy, the power input on rear (SFC) side of the chassis should be from two different branch sources, with the left two input connections to one branch source and the right two to the other branch source. With this configuration the router remains fully powered in case one branch source fails. In normal operation all power supplies should be installed.

Be sure to install the power shelf before installing the power supplies.

Caution If you install a non-Cisco power supply in the chassis, upon its detection as a non-compliant power supply, the system will shut down. Using non-Cisco power supplies MAY RESULT IN COMPLETE CHASSIS SHUTDOWN due to insufficient power.

Supplemental Unit Bonding and Grounding Guidelines

Although the router chassis has a safety earth ground connection as part of the power cabling to the power shelf, the chassis includes an option that allows you to connect the central office ground system or interior equipment ground system to the supplemental bonding and grounding receptacles on the router chassis. Two ground studs are located on the rear (SFC) side of the chassis. (see Figure 2-1). This ground point is also called the network equipment building system (NEBS) bonding and grounding stud.

Note These bonding and grounding receptacles satisfy the Telcordia® NEBS requirements for supplemental bonding and grounding connections. If you are not installing the router in a NEBS environment, you can choose to bypass these guidelines and rely on the safety earth ground connection for the power shelf.

Cisco CRS-1 Carrier Routing System 4-Slot Line Card Chassis Installation Guide

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