Guidelines For Dc-Powered Systems; Guidelines For Ac-Powered Systems; Preventing Esd Damage - Cisco NCS 540 Hardware Installation Manual

Guidelines for DC-Powered Systems

Warning
This product requires short-circuit (overcurrent) protection, to be provided as part of the building installation.
Install only in accordance with national and local wiring regulations. Statement 1045
Guidelines for DC-Powered Systems
Basic guidelines for DC-powered systems include the following:
• Each chassis power supply has its own dedicated input power source. The source must comply with the
• Protect the circuit by a dedicated two-pole circuit breaker. Ensure that the circuit breaker is 12A rated.
• The circuit breaker is considered as the disconnect device and is easily accessible.
• The system ground is the power supply and chassis ground.
• Use the grounding lug to attach a wrist strap for ESD protection during servicing.
• Do not connect the DC return wire to the system frame or to the system-grounding equipment.
• Ensure that the DC return is grounded at the source side.

Guidelines for AC-Powered Systems

Basic guidelines for AC-powered systems include the following:
• Each chassis power supply has its own dedicated branch circuit.
• Ensure that the circuit breaker is 7A rated.
• The AC power receptacles that are used to plug in the chassis must be the grounding type. The grounding

Preventing ESD Damage

Warning Ground this equipment. Use a green and yellow 6-AWG ground wire to connect the host to earth ground
during normal use. Statement 383
Electrostatic Discharge (ESD) can damage equipment and impair electrical circuitry. ESD may occur when
electronic printed circuit cards are improperly handled and can cause complete or intermittent failures. When
removing and replacing modules, always follow these ESD prevention procedures:
• Ensure that the device chassis is electrically connected to earth ground.
• Wear an ESD-preventive wrist strap, ensuring that it makes good skin contact. To channel unwanted
• If no wrist strap is available, ground yourself by touching a metal part of the chassis.
• When installing a component, use any available ejector levers or captive installation screws to properly
Cisco Network Convergence System 540 Large Density Routers Hardware Installation Guide
6
safety extra-low voltage (SELV) requirements in the UL 60950, CSA 60950, EN 60950, and IEC 60950
standards.
conductors that connect to the receptacles must connect to protective earth ground at the service equipment.
ESD voltages safely to ground, connect the clip to an unpainted surface of the chassis frame. To guard
against ESD damage and shocks, the wrist strap and cord must operate effectively.
seat the bus connectors in the backplane or midplane. These devices prevent accidental removal, provide
proper grounding for the system, and help to ensure that bus connectors are properly seated.
Safety Warnings