Section 2.2 Hand and Power Tool Safety 33
• Do not use the machine in a wet location or
where there are explosive vapors.
• Inspect the machine’s power cord before
starting it. If the cord is frayed, split, or
worn, do not use the machine. Do not use
the machine if the grounding pin is missing
from a three-prong plug.
• When setting up the machine for a job or
when making adjustments, always remove
the plug from the wall receptacle or switch
the electrical disconnect to the OFF position.
• Determine the method of starting and
stopping the machine before using it.
After finishing a job, do not leave the
machine unattended until it has come to a
complete stop.
• Remove all adjustment wrenches, unneeded
tools, and extra material from a power
machine table before the power is turned on.
• Make sure all guards are in place. Special
setup jigs and accessories should be
properly positioned and secured. If the
guard must be removed for a certain
procedure, ask the instructor for permission
before removing the guard. After you have
removed the guard, ask the instructor to
check the setup and discuss the procedure.
Finally, ask the instructor to assist you in
the procedure. Instructors have valuable
experience and knowledge of the machines!
• Do not attempt to operate a power machine
that has a dull blade. Blades tend to overheat
when dull, causing them to warp or break
easily without warning. Dull blades also
cause the motor to overheat, which may
result in permanent damage to the machine.
In addition, a dull blade burns the cut
surface of the wood. The surface will then
need extra sanding, or it will not readily
accept glue or a fi nish.
Electrical Safety
When several tools or machines are in use at
the same time, circuits may become overloaded,
Figure 2-19. Overloads often occur when a num-
ber of extension cords have been connected to-
gether. The current-carrying capacity of each
extension cord is reduced. If a power tool that
exceeds this new current-carrying capacity is
operated, the cord may overheat, or the power
tool will operate with less power than required.
The tool itself may overheat, resulting in a loss of
effi ciency, damage to the tool if operated for any
length of time, or possible injury to the operator.
The National Electrical Code requires all
new wiring in basements, garages, bathrooms,
and outdoor locations to have ground fault
protection. A ground fault is an unintended
electrical path between a power source and
a grounded surface. For example, if you are
working with a faulty electric tool, your body
could become a path to ground for the current. A
ground fault circuit interrupter (GFCI) senses
when a ground fault exists and immediately
breaks the circuit. This protects the operator
from electrical shock, Figure 2-20.
Figure 2-19. When too many tools or machines are
drawing current from the same circuit, the circuit
can become overloaded. The result can be a tripped
circuit breaker or even a fi re.
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