Installation guide

Overview of Cisco WAN and Voice Interface Cards 1-19
Safety with Electricity
Safety with Electricity
Follow these guidelines when working on equipment powered by electricity:
• Locate the emergency power-off switch in the room in which you are working. Then, if
an electrical accident occurs, you can quickly shut the power OFF.
• Before working on the router, turn OFF the power and unplug the power cord.
Warning Before working on equipment that is connected to power lines, remove jewelry
(including rings, necklaces, and watches). Metal objects will heat up when connected to
power and ground and can cause serious burns or weld the metal object to the terminals.
Warning To avoid electric shock, do not connect safety extra-low voltage (SELV)
circuits to telephone-network voltage (TNV) circuits. LAN ports contain SELV circuits,
and WAN ports contain TNV circuits. Both LAN and WAN ports may use RJ-45
connectors. Use caution when connecting cables.
Warning Hazardous network voltages are present in WAN ports regardless of whether
power to the router is OFF or ON. To avoid electric shock, use caution when working near
WAN ports. When detaching cables, detach the end away from the router first.
Warning Before opening the chassis, disconnect the telephone-network cables to avoid
contact with telephone-network voltages.
Warning Do not work on the system or connect or disconnect cables during periods of
lightning activity.
Warning Do not touch the power supply when the power cord is connected. For systems
with a power switch, line voltages are present within the power supply even when the
power switch is OFF and the power cord is connected. For systems without a power
switch, line voltages are present within the power supply when the power cord is
connected.