IBM 4247 Maintenance Information page 14

Remember: There must be a complete circuit to cause electrical shock. By observing the above rule, you
may prevent a current from passing through your body.
– When using testers, set the controls correctly and use the approved probe leads and accessories for that
tester.
DANGER
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.
– Stand on suitable rubber mats (obtained locally, if necessary) to insulate you from grounds such as metal
floor strips and machine frames.
Observe the special safety precautions when you work with very high voltages; these instructions are in the
safety sections of maintenance information. Use extreme care when measuring high voltages.
v Regularly inspect and maintain your electrical hand tools for safe operational condition.
v Never assume that power has been disconnected from a circuit. First, check that it has been powered off (O).
v Always look carefully for possible hazards in your work area. Examples of these hazards are moist floors,
nongrounded power extension cables, power surges, and missing safety grounds.
v Do not touch live electrical circuits with the reflective surface of a plastic dental mirror. The surface is
conductive; such touching can cause personal injury and machine damage.
v To ensure correct grounding, do not service the following parts with the power on when they are removed from
their normal operating places in a machine:
– Power supply
– Fans
– Motors
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Safety Information