Electrical Safety - Lenovo 90H9 Hardware Maintenance Manual

Electrical safety

CAUTION:
Electrical current from power, telephone, and communication cables can be
hazardous. To avoid personal injury or equipment damage, disconnect the
attached power cords, telecommunication systems, networks, and modems
before you open the computer covers, unless instructed otherwise in the
installation and configuration procedures.
Observe the following rules when working on electrical equipment.
Important: Use only approved tools and test equipment. Some hand tools have
handles covered with a soft material that does not insulate you when working with
live electrical currents.
Many customers have, near their equipment, rubber floor mats that contain small
conductive fibers to decrease electrostatic discharges. Do not use this type of mat
to protect yourself from electrical shock.
• Find the room emergency power-off (EPO) switch, disconnecting switch, or
electrical outlet. If an electrical accident occurs, you can then operate the
switch or unplug the power cord quickly.
• Do not work alone under hazardous conditions or near equipment that has
hazardous voltages.
• Disconnect all power before:
– Performing a mechanical inspection
– Working near power supplies
– Removing or installing Field Replaceable Units (FRUs)
• Before you start to work on the machine, unplug the power cord. If you cannot
unplug it, ask the customer to power-off the wall box that supplies power to
the machine and to lock the wall box in the off position.
• If you need to work on a machine that has exposed electrical circuits, observe
the following precautions:
– Ensure that another person, familiar with the power-off controls, is near
you.
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