Cisco ASR 903 Installation Manual page 65

Preparing for Installation
Warning
When you connect or disconnect the power and relay connector with power applied, an electrical arc can
occur. This could cause an explosion in hazardous area installations. Be sure that power is removed from the
switch and alarm circuit. Be sure that power cannot be accidentally turned on or verify that the area is
nonhazardous before proceeding. Failure to securely tighten the power and relay connector captive screws
can result in an electrical arc if the connector is accidentally removed. Statement 1058
Warning Failure to securely tighten the power and relay connector captive screws can result in an electrical arc if the
connector is accidentally removed. Statement 397
Warning This equipment is intended to be grounded. Ensure that the host is connected to earth ground during normal
use.
Warning
If you connect or disconnect the console cable with power applied to the switch or any device on the network,
an electrical arc can occur. This could cause an explosion in hazardous location installations. Be sure that
power is removed or the area is nonhazardous before proceeding. To verify switch operation, perform POST
on the switch in a nonhazardous location before installation. Statement 1065
Warning
Installation of the equipment must comply with local and national electrical codes. Statement 1074
Warning
Hazardous voltage or energy may be present on DC power terminals. Always replace cover when terminals
are not in service. Be sure uninsulated conductors are not accessible when cover is in place. Statement 1075
When working on equipment powered by electricity, follow these guidelines:
• Locate the room's emergency power-off switch. If an electrical accident occurs, you will be able to
quickly turn off the power.
• Before working on the system, turn off the DC main circuit breaker and disconnect the power terminal
block cable.
• Before doing the following, disconnect all power:
• Never install equipment that appears damaged.
• Carefully examine your work area for possible hazards, such as moist floors, ungrounded power extension
cables, and missing safety grounds.
• Never assume that power is disconnected from a circuit; always check.
• Never perform any action that creates a potential hazard to people or makes the equipment unsafe.
• Working on or near power supplies
• Installing or removing a router chassis or network processor module
• Performing most hardware upgrades
Cisco ASR 903 and ASR 903U Aggregation Services Router Hardware Installation Guide
Safety with Electricity
55