TM 5-3810-306-10
Proximity sensing devices are available in different
types. Some use boom nose (localized) sensors and
others use full boom length sensors. No warning may be
given for components, cables, loads, etc. located outside
of the sensing area. Responsibility is on you, the
operator, in selecting and properly setting sensitivity of
these devices.
Never rely soley on a device to protect you and your
fellow workers from danger!
Some variables which you must be aware of are:
1.
Proximity devices detect the existence of
electricity -- not it’s quantity or magnitude.
2.
Some
proximity
devices
will
detect
only
alternating current (AC) -- not direct current
(DC).
3.
Some devices detect radio frequency (RF)
energy -- others do not.
4.
Most proximity devices simply provide a signal
(audible, visual or both) -- the signal must not be
ignored.
5.
Proximity devices often become confused by
complex
or
differing
arrays
of
power
lines/sources.
Plan ahead and plainly mark a safe route before
traveling under power lines. Erect rider poles on each
side of the crossing to assure sufficient clearance is
maintained.
Overhead lines tend to blow with wind. Allow for this
when determining safe operating distances.
DO NOT store material under power lines or close to
electrical power sources.
Grounding the crane offers little or no protection from
electrical hazards. The grounding effect is limited by the
wire size used, the condition of the ground, amount of
voltage and current present, etc. Power source contacts
have been known to cause serious arcing due to
grounding.
Tag lines should always be made of non-conductive
materials.
Any tag line that is wet or dirty can conduct
electricity.
Working
in
the
vicinity
of
radio
frequency
transmission towers/sources may cause a crane to
become electrically "charged." Survey the work site and
develop specific safety precautions and operating
procedures, prior to commencing operations.
If contact is made with a power source - THINK -
DON’T PANIC.
1.
Warn everyone to stay away from the crane.
2.
Attempt to free the crane by operating the crane
functions.
3.
Stay in the crane until the power source has
been turned off.
You should, only as a last resort, attempt to leave the
crane after contacting a power source.
If it is absolutely necessary to leave the cab, JUMP
COMPLETELY CLEAR OF THE CRANE - DO NOT
STEP OFF. Hop away with both feet together. DO NOT
walk or run.
Following any contact with an energized electrical
source, thoroughly inspect the wire rope and all points of
contact with the crane.
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