Cisco Systems MGX 8800, MGX 8900 DC Power Guidelines for MGX Switches

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Cisco MGX 8800/8900 Series Hardware Installation Guide

Releases 2 - 5.2, Part Number OL-4545-01, Rev. H0, May 2006

Chapter3 Preparing for Installation

Safety Requirements

•Use the Cisco MGX AC and DC systems within the specifications provided by their marked

electrical ratings and product usage instructions .

•Install the Cisco MGX AC and DC systems with the following local, national, or international

electrical codes:

–

United States—National Fire Protection Association (NFPA70), United States National

Electrical Code

–

Canada—Canadian Electrical Code, Part 1, CSA C22.1

–

Other countries—International Electromechanical Commission ( IEC) 364, Part 1 through Part 7

•AC models of Cisco MGX systems are shipped with a 3-wire electrical cord with a grounding -type

plug that fits only a grounding-type power outlet. This is a safet y feature that you should not

circumvent. Equipment grounding should comply with local and national electri cal codes.

DC Power Guidelines for MGX Switches

Only a DC power source that complies with the safety extra low voltage (SELV) requirements of UL

1950, CSA C22.2 No. 950-95, EN 60950, and IEC 950 can be connected to a D C PEM in the MGX 8850

or MGX 8850/B switch.

MGX 8850 or MGX 8850/B switches equipped with DC PEM(s) are intended for installation only in a

restricted access location. In the United States, a restricted access area is one that meets the

specifications in Articles 110-16, 110-17, and 110-18 of the National Electrical Code ANSI/NFPA 70.

DC models for MGX 8850 and MGX 8850/B switches are equipped with DC power entry modules

(PEMs) and require you to terminate the DC input wiring on a DC source capable of supplying at least

60 A. A 60 A circuit breaker is required at the –48 VDC facility power source.

DC models of MGX 8950 switches are equipped with DC power entry modules ( PEMs) and require you

to terminate the DC input wiring on a DC source cap able of supplying at least 100 A. A 100 A circuit

breaker is required at the –48 VDC facility power source.

DC models of MGX 8830 or MGX 8830/B systems are equipped with DC power entry mod ules (PEMs)

and require you to terminate the DC input wiring on a DC source capable of supplying at least 30 A. A

30 A circuit breaker is required at the –48 VDC facility power source.

Caution An easily accessible disconnect device should be incorporated into the facility wiring. Be sure to connect

the grounding wire conduit to a solid earth ground. Use of a closed loop ring is recommended for

terminating the ground conductor at the ground stud.