Power And Ground Cabling Overview; Grounding Topologies - Nortel Passport 15000 Preparation Manual

Power and ground cabling overview

Grounding topologies

CAUTION
Risk of service interruption
An MFA150 power system of ac rectifiers is rated as class
A equipment, therefore it requires an appropriately
controlled environment for your site setup.
For more information on installing power cables for the MFA150 power
system, see the Astec document 167-9021-133 Advanced Power Systems
MFA150 Modular Front Access Power System Detailed Installation
Guidelines and Procedures Manual.
The NEBS 2000 frame in which one or two Passport 15000 or 20000 switches
are mounted has the versatility to use either top or bottom cable routing for
the power feeds and the top frame ground (labeled with the standard icon). A
-48/-60 V dc power source is required. It must be reliably connected to
ground and must be electrically isolated from the ac source. Before you
proceed, review the following information and procedures:
• "Grounding topologies" (page 153)
• "General grounding rules for IBN and CBN topologies" (page 156)
There are three grounding topologies to choose from depending on your
location and requirements:
• Isolated bonding network (IBN), which is used in North America and is
isolated from the floor (see the figure "IBN grounding" (page 154))
• Common bonding network (CBN), which is used in North America (see
the figure "CBN grounding" (page 155)
• Mesh-BN, which is the standard for the European Telecommunications
Standards Institutes (ETSI). The requirements for this grounding
topology are similar to CBN, except that each battery return (BR) must
be bonded to the frame ground (FG).
Passport 15000, 20000 Site Requirements and Preparation Guide
Chapter 4 Power and grounding preparation 153
5.2S2