Installing Dc Input Power Supplies - Cisco Catalyst 8500 Series Hardware Installation Manual

Removing and Replacing FRUs

Installing DC Input Power Supplies

Warning To reduce risk of electric shock, before performing any of the following procedures, ensure that power is
removed from the system.
Warning
Only trained and qualified personnel should be allowed to install, replace, or service this equipment.
Note Do not install the power supplies with the chassis cover off.
This section describes how to install the DC power supply input power leads to the DC input power supply.
Before you begin, read these important notices:
• The color coding of the DC input power supply leads depends on the color coding of the DC power
• Ensure that the chassis ground is connected on the chassis before you begin installing the DC power
• For DC input power cables, the wire gauge is based on the National Electrical Code (NEC) and local
Each DC input power cable is terminated at the PDU by a cable lug, as shown in the following figure.
Note
DC input power cables must be connected to the PDU terminal studs in the proper positive (+) and negative
(–) polarity. In some cases, the DC cable leads are labeled, which is a relatively safe indication of the polarity.
However, you must verify the polarity by measuring the voltage between the DC cable leads. When making
the measurement, the positive (+) lead and the negative (–) lead must always match the (+) and (–) labels on
the power distribution unit.
Figure 8: DC Input Power Cable Lug
source at your site. Ensure that the lead color coding you choose for the DC input power supply matches
the lead color coding used at the DC power source and verify that the power source is connected to the
negative (–) terminal and to the positive (+) terminal on the power supply.
supply. Follow the steps provided in the Chassis Ground Connection section.
codes for 26 amp service at nominal DC input voltage (–40/–72 VDC). One pair of cable leads, source
DC (–) and source DC return (+), are required for each power distribution unit (PDU). These cables are
available from any commercial cable vendor. All DC input power cables for the chassis should be 10
gauge wire and cable lengths should match within 10 percent of deviation.
Cisco Catalyst 8500 Series Edge Platforms Hardware Installation Guide

Installing DC Input Power Supplies

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