Cisco GSR12/60 - 12012 Router -AnyLAN, SONET/SDH Installation And Configuration Manual page 154

Connecting Power
The card cage assembly power supply bays are labeled A1, A2, B1, and B2 (from left to
right). If your Cisco 12012 is configured with only one DC-input power supply, reinstall
the power supply in power supply bays A1/A2. If your Cisco 12012 is configured with a
second (redundant) DC-input power supply, reinstall it in power supply bays B1/B2.
Note
proper airflow and for EMI considerations.
Perform the following steps to reinstall a DC-input power supply:
Caution
the power supply.
Step 1
Step 2
Step 3
3-58 Cisco 12012 Gigabit Switch Router Installation and Configuration Guide
Unoccupied power supply bays must have power supply blanks installed to maintain
The DC-input power supply weighs 19 lb (8.3 kg). Use two hands when handling
Attach an antistatic wrist strap to yourself and to one of the two ESD connection
sockets located on the front edges of the upper card cage or to bare metal on the
frame.
Verify that the DC-input power supply power switch is turned OFF (O).
Place the DC-input power supply faceplate-up, in front of the empty power
supply bay.