Cisco 12012 Replacement Instructions Manual page 2

Product Overview
Figure 1
Bottom blower module
(behind front cover)
The lower card cage, located behind the air filter, has five horizontal slots for switch fabric cards.
The Cisco 12012 supports up to two DC-input power supplies in a power supply bay located below
the lower card cage. (Refer to Figure 1.) The power supply bay is divided into four positions
designated A1, A2, B1, and B2 (from left to right). Cisco 12012 systems come standard with one
DC-input power supply installed in power supply bay positions A1 and A2. Power supply bay
positions B1 and B2 have power supply blanks installed to maintain airflow and for EMI
considerations. You can install a second DC-input power supply in power supply bay positions B1
and B2 for power supply redundancy and current sharing.
Caution
configuration is not supported and can cause system damage.
In systems with redundant power (two DC-input power supplies), you can install, remove, or replace
one of the power supplies without affecting system operation. When power is removed from one
power supply, the redundant power supply maintains uninterrupted system operation.
The DC-input power supply is a modular unit measuring 7.8-inches (20-cm) wide by 10-inches
(25.4-cm) wide by 15-inches (38-cm) deep and weighing 19 lb (8.6 kg). (Refer to Figure 2.) The
power supply slides in and out of the power supply bay and is secured in place by a combination of
a single captive jackscrew on the power supply faceplate and a latch, which is part of the power
on/off switch also located on the power supply faceplate.
2 Cisco 12012 Gigabit Switch Router DC-Input Power Supply Replacement Instructions
Cisco 12012—Front View
Top blower module
(behind front cover)
Upper card cage
Air filter tray
Power supply bay
Do not mix DC-input and AC-input power supplies in the same Cisco 12012. This
Lower card cage
(behind air filter)