Folio 1113-7
SAFE OPERATING PRACTICES
magnitude, can arc or jump to any part of the load, load line,
or crane boom if it comes too close to an electrical power
source. Low voltages can also be dangerous.
Set-Up and Operation
During crane use, assume that every line is energized (“hot”
or “live”) and take necessary precautions.
Position the crane such that the load, boom, or any part of
the crane and its attachments cannot be moved to within 20
ft (6 m) of electrical power lines or equipment. This includes
the crane boom and all attachments. Overhead lines tend to
blow in the wind so allow for lines’ movement when
determining safe operating distance.
A suitable barricade should be erected to physically restrain
the crane, all attachments, and the load from entering into an
unsafe distance from electrical power lines or equipment.
Plan ahead and always plan a safe route before traveling
under power lines. Rider poles should be erected on each
side of a crossing to assure sufficient clearance is
maintained.
Appoint a reliable and qualified signal person, equipped with
a loud signal whistle or horn and voice communication
equipment, to warn the operator when any part of the crane
or load moves near a power source. This person should have
no other duties while the crane is working.
Tag lines should always be made of non-conductive
materials. Any tag line that is wet or dirty can conduct
electricity.
DO NOT store materials under power lines or close to
electrical power sources.
Electrocution Hazard Devices
The use of insulated links, insulated boom cages/guards,
proximity warning devices, or mechanical limit stops does
not assure that electrical contact will not occur. Even if codes
or regulations require the use of such devices, failure to
follow the rules in this section may result in serious injury or
death.
Be aware that such devices have limitations and you should
follow the rules and precautions outlined in this section at all
times even if the crane is equipped with these devices.
Insulating links installed into the load line afford limited
protection from electrocution hazards. Links are limited in
their lifting abilities, insulating properties, and other
properties that affect their performance. Moisture, dust, dirt,
oils, and other contaminants can cause a link to conduct
electricity. Due to their capacity ratings, some links are not
effective for large cranes and/or high voltages/currents.
The only protection that may be afforded by an insulated link
is below the link (electrically downstream), provided the link
has been kept clean, free of contamination, has not been
scratched or damaged, and is periodically tested (just before
use) for its dielectric integrity.
Boom cages and boom guards afford limited protection from
electrocution hazards. They are designed to cover only the
boom nose and a small portion of the boom. Performance of
boom cages and boom guards is limited by their physical
size, insulating characteristics, and operating environment
(e.g. dust, dirt, moisture, etc.). The insulating characteristics
of these devices can be compromised if not kept clean, free
of contamination, and undamaged.
Proximity sensing and warning 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, and other attachments
located outside of the sensing area.Reliance is placed upon
the operator in selecting and properly setting the sensitivity
of these devices.
Never rely solely on a device to protect you and your fellow
workers from danger.
Some variables you must know and understand are:
• Proximity devices are supposed to detect the existence
of electricity and not its quantity or magnitude.
• Some proximity devices will detect only alternating
current (AC) and not direct current (DC).
• Some proximity devices detect radio frequency (RF)
energy and others do not.
• Most proximity devices simply provide a signal (audible,
visual, or both) for the operator and this signal must not
be ignored.
• Sometimes the sensing portion of the proximity devices
becomes confused by complex or differing arrays of
power lines and power sources.
DO NOT depend on grounding. Grounding of a crane affords
little or no protection from electrical hazards. The
effectiveness of grounding is limited by the size of the (wire)
conductor used, the condition of the ground, the magnitude
of the voltage and current present, and numerous other
factors.
Electrical Contact
If the crane comes in contact with an energized power
source, the operator must:
1. Stay in the crane cab. DON’T PANIC.
2. Immediately warn PERSONNEL in the vicinity to STAY
AWAY.
3. Attempt to move the crane away from the contacted
power source using the crane’s controls which are likely
to remain functional.
4. Stay in the crane until the power company has been
contacted and the power source has been de-energized.
NO ONE must attempt to come close to the crane or
load until the power has been turned off.
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