Cisco XR 12406 - Manual (Page 53)

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Cisco XR 12406 Router Installation Guide
OL-13831-01
Chapter 1 Cisco XR 12406 Router Overview
Line Cards
Power Distribution
The router chassis backplane distributes -48 VDC power throughout the router
and to all cards in the card cages.
All cards have multiple DC-DC converters that convert the -48 VDC into
+2.5 VDC, +3.3 VDC, +5 VDC, and other voltages as required by the line card.
The DC-DC converters are turned on by the MBus modules under the control of
the route processor and MBus software.
Power for the blower module is supplied directly from the backplane through a
connector in the PDU that passes DC voltage from the backplane to the blower
module. An blower module controller card in the blower module converts
–48 VDC into DC voltage that powers the blower module fans.
Caution To ensure that the chassis configuration complies with the required power
budgets, use the on-line power calculator. Failure to properly verify the
configuration may result in an unpredictable state if one of the power units fails.
Contact your local sales representative for assistance.
Blower Module
The Cisco XR 12406 Router is equipped with a blower module to distribute air
within the chassis. The blower module is located on the rear of the chassis (see
Figure 1-3 ). The blower module draws room air into the chassis through two air
filters on the side of the chassis, pulls the air through the chassis card cages, and
expels it through exhaust vents on the back of the blower module (
Figure 1-17 ).
Caution Exhaust from other equipment vented directly into the router air inlet may cause
overheating. The front, back, and sides of the router must remain unobstructed to
ensure adequate air flow and prevent overheating inside the chassis. Allow
sufficient air flow by maintaining 6 inches (15.24 cm) of clearance at both the
inlet and exhaust openings on the chassis.