Preventing Power Loss; Power Connection Guidelines - Cisco ASR 903 Installing Manual

Preventing Power Loss

Preventing Power Loss
Use the following guidelines to prevent power loss to the router.
• To prevent loss of input power, ensure that the total maximum load on each circuit supplying the power
• In some systems, you can use an UPS to protect against power failures at your site. Avoid UPS types
Use the information in the
of a Cisco ASR 903 Router based on a given configuration of the router. Determining power requirements is
useful for planning the power distribution system needed to support the router.

Power Connection Guidelines

This section provides guidelines for connecting the Cisco ASR 903 Router power supplies to the site power
source.
Never defeat the ground conductor or operate the equipment in the absence of a suitably installed ground
Warning
conductor. Contact the appropriate electrical inspection authority or an electrician if you are uncertain
that suitable grounding is available. Statement 213
The plug-socket combination must be accessible at all times because it serves as the main disconnecting
Warning
device. Statement 1019
This product requires short-circuit (overcurrent) protection, to be provided as part of the building installation.
Warning
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 should have its own dedicated input power source. The source must comply
• The circuit must be protected by a dedicated two-pole circuit breaker. The circuit breaker should be
• The circuit breaker is considered the disconnect device and should be easily accessible.
• The system ground is the power supply and chassis ground.
• Do not connect the DC return wire to the system frame or to the system grounding equipment.
Cisco ASR 903 and ASR 903U Aggregation Services Router Hardware Installation Guide
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supplies is within the current ratings of the wiring and breakers.
that use ferroresonant technology. These UPS types can become unstable with systems like the Cisco
ASR 903 Router, which can have substantial current draw fluctuations due to bursty data traffic patterns.
DC Power Specifications
with the safety extra-low voltage (SELV) requirements in the UL 60950, CSA 60950, EN 60950, and
IEC 60950 standards.
sized according to the power supply input rating and local or national code requirements.
Installing the Cisco ASR 903 Router
to estimate the power requirements and heat dissipation