For high-availability and fault-tolerant installations in which the switches use redundant power supply
units (PSUs), we recommend that each PSU in a switch be connected to a different UPS and that each
UPS be powered by an independent AC supply. This will prevent service interruptions when a power
source is lost, or when a UPS unit fails. (Note that a single, appropriately sized UPS can power PSUs in
multiple switches. The recommendation is simply that for any given switch, the two PSUs should be
connected to different UPS units.)
DC Power Requirements
This system should be installed in a DC-I battery return configuration.
In a DC-I configuration, the battery return conductor should be connected directly to the central office
power return bus, and not to the equipment frame or the grounding means of the equipment.
Following Applicable Industry Standards
Always follow applicable industry standards.
For more information, see the following ANSI/TIA/EIA standards:
•
ANSI/TIA/EIA-568-A—the six subsystems of a structured cabling system
•
ANSI/TIA/EIA-569-A—design considerations
•
ANSI/TIA/EIA-606—cabling system administration
•
ANSI/TIA/EIA-607—commercial building grounding and bonding requirements
You can access these standards at:
.
DC Power Requirements
Site Preparation
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ExtremeSwitching Hardware Installation Guide