Earthing And Bonding Recommendations - Cisco MGX MGX 8800 Hardware Installation Manual

Earthing and Bonding Recommendations

This appendix applies to the Cisco MGX switches and gateways described in this guide: MGX 8850
Note
(PXM45/PXM1E), MGX 8850/B, MGX 8950, MGX 8830 and MGX 8830/B multiservice switches and
the MGX 8880 Media Gateway.
This appendix discusses the techniques and policies that Cisco practices with regard to DC power,
earthing, and bonding of Cisco equipment. It also explains why these techniques are the best practice.
More specifically, this appendix describes the techniques for DC power and earth bonding for
Cisco MGX switches.
The appendix also discusses the principles of mesh bonding and explains the earth return systems that
are used in the Cisco MGX switch. It identifies the earthing points, shows how they are to be earthed,
and how the DC power connections are to be connected to the equipment.
The earthing and powering techniques described in this appendix are extracts from Cisco internal
documentation, engineering documentation, and the following standards documentation:
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Scope
The bonding and earthing principles adopted by Cisco are as follows:
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This appendix supports the principles listed above by providing information that complies with relevant
safety standards on the following topics:
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Releases 2 - 5.2, Part Number OL-4545-01, Rev. H0, May 2006
ITU-T K.27, Bonding configurations and earthing inside a telecommunications building
GR-1089-CORE, Electromagnetic compatibility and electrical safety—generic criteria for network
telecommunications equipment
Promote personal safety and reduce fire hazards
Enable telecomm signaling with earth return
Minimize equipment damage and service interruption
Minimize radiated and conducted electromagnetic emissions and susceptibility
Maximize tolerance to discharge of electrostatic energy and lightning interference
Bonding and earthing of the Cisco WAN equipment at the telco sites
Shielding provided by cabinets, cable trays, and cable shields
Techniques for verifying and maintaining bonding and earthing networks
A P P E N D I X
Cisco MGX 8800/8900 Series Hardware Installation Guide
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