Cisco ASR 903 Quick Start Manual page 16

Procedure
Step 1 Ensure that the system (earth) ground connection has been made. For ground connection installation instructions, see
Installing the Chassis Ground Connection section in the Cisco ASR 903 and ASR 903U Aggregation Services Router
Hardware Installation Guide.
Step 2 If necessary, remove the blank power supply filler plate from the chassis power supply bay opening by loosening the
captive installation screws.
Step 3 Verify that power to the DC circuit connected to the power supply you are installing is off. To ensure that power has been
removed from the DC circuits, locate the circuit breakers for the DC circuits, switch the circuit breakers to the OFF position,
and tape the circuit-breaker switches in the OFF position.
Step 4 Grasp the power supply handle with one hand. Place your other hand underneath the power supply, as shown in the figure
below . Slide the power supply into the power supply bay. Make sure that the power supply is fully seated in the bay.
Figure 11: Installing the DC Power Supply
Step 5 Tighten the captive installation screws of the power supply. The recommended maximum torque is 25 in.-lb (2.82 N-m).
If you are installing a redundant DC power supply, repeat these steps for the second power source.
Installing the AC Power Supply Module for A900-PWR550-A (550 W) and A900-PWR1200-A (1200
W)
Follow these steps to install the power supply module:
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