beautypg.com

Safety with electricity – Cisco 3620 User Manual

Page 4

background image

4 Installing a Fan-Speed Controller in Cisco 3620 Routers

Safety Recommendations

Warning

Ultimate disposal of this product should be handled according to all national laws and regulations.

Safety with Electricity

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.

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.

Disconnect all power before doing the following:

Installing or removing a router chassis

Working near power supplies

Do not work alone if potentially hazardous conditions exist.

Never assume that power is disconnected from a circuit. Always check.

Look carefully for possible hazards in your work area, such as moist floors, ungrounded power
extension cables, and missing safety grounds.