Chapter2 Preparing for Installation
Power Connection Guidelines
2-8
Cisco7609 Internet Router Installation Guide
OL-5079-04
Power Requirements
Follow these requirements when preparing your site for the swit ch installation:
•The redundant power option provides a second, identical power supply to
ensure that power to the chassis continues uninterrupted if one power supply
fails or input power on one line fails.
•In systems configured with the redundant power option, connect each of the
two power supplies to a separate input power source. If you fail to do this,
your system might be susceptible to total power failure due to a fault in the
external wiring or a tripped circuit breaker.
•To prevent a loss of input power, be sure the total maximum load on each
circuit supplying the power supplies is within the current ratings of the wiring
and breakers.
•In some systems, you might use an uninterruptible power supply (UPS) to
protect against power failures at your site. Avoid UPS types that use
ferroresonant technology. These UPS types can become unstable with
systems like the Cisco 7609 Internet Router, which can have substantial
current draw fluctuations due to bursty data traffic patterns.
Use the information in Table 2 -2 to estimate the power requirements and heat
dissipation of a Cisco 7609 Internet Router based on a given configuration of the
switch. Table 2 -4 provides a sample calculation. Determining power requirements
might be useful for planning the power distribution system needed to su pport the
switch.
Power Connection Guidelines This section provides the guidelines for connecting the Cisc o 7609 Internet
Router AC and DC power supplies to the site power source.
•AC-Powered Systems, page 2-9
•DC-Powered Systems, page2-11