Cisco 6509 Installation Guide - Page 101

Chapter 2 Preparing for Installation Cabling Requirements Power Connection Guidelines for DC-Powered Systems This section provides the basic guidelines for connecting the Catalyst 6500 series switch DC-input power supplies to the site power source: • All power connection wiring should conform to the rules and regulations in the National Electrical Code (NEC), as well as any local codes. • The DC return is to remain isolated from the system frame and the chassis (DC-I). • For DC power cables, we recommend that you use commensurately rated, high-strand-count copper wire cable. Connection to the DC-input power supply requires one earth ground cable, one source DC (-), and one source DC return (+). The length of the cables depends on your switch location. These cables are not available from Cisco Systems. They are available from any commercial cable vendor. • The color coding of the source DC power cable leads depends on the color coding of the site DC power source. Typically, green or green and yellow indicate that the cable is a ground cable. Because there is no color code standard for source DC wiring, you must ensure that the power cables are connected to the DC-input power supply terminal block in the proper (+) and (-) polarity. In some cases, the source DC cable leads might have a positive (+) or a negative (-) label. This label is a relatively safe indication of the polarity, but 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 DC-input power supply terminal block. • DC power cables must be terminated by cable lugs at the power supply end. • The circuit breaker is considered the disconnect device and should be easily accessible. • The circuit must be protected by a dedicated two-pole circuit breaker. The circuit breaker should be sized according to the power supply input rating and local or national code requirements. Cabling Requirements Caution The intrabuilding port(s) of the equipment or subassembly is suitable for connection to intrabuilding or unexposed wiring or cabling only. The intrabuilding port(s) of the equipment or subassembly must not be metallically connected to interfaces that connect to the Outside Plant (OSP) or its wiring. These interfaces are designed for use as intrabuilding interfaces only (Type 2 or Type 4 ports as described in GR-1089-CORE, Issue 4) and require isolation from the exposed OSP cabling. The addition of Primary Protectors is not sufficient protection to connect these interfaces metallically to OSP wiring. When running power and data cables together in overhead cable trays or subfloor cable trays, be aware of the following caution: Caution We strongly recommend that power cabling runs and other potential noise sources be located as far away as practical from LAN cabling that terminates on Cisco equipment. In situations, where this type of long parallel cable runs exist which cannot be separated by at least 3.3 feet (1 meter), we recommend that you shield these potential noise sources. To avoid interference, the source should be shielded by housing it in a grounded metallic conduit. OL-5781-04 Catalyst 6500 Series Switches Installation Guide 2-21