Manitowoc MLC150-1, Руководство по техническому обслуживанию

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HOISTS MLC150-1 SERVICE/MAINTENANCE MANUAL
5-42
Published 03-21-2021, Control # 264-01
Replacement Criteria
Deciding when a wire rope should be replaced is the
responsibility of the qualified person who is appointed to
review rope inspection records and evaluate rope condition.
The following are indications that the rope needs to be
replaced:
• Reduction in the rope diameter and excessive broken
wires (see
Reduction in the Rope Diameter on page 5-
42 and Broken Rope Wires on page 5-42 )
• Wear of one-third of the original diameter of outside
individual wires
• Kinking, crushing, bird caging, or any other damage
resulting in distortion of the rope structure
• Evidence of any heat damage from any cause
• Severe corrosion as evidenced by pitting
• Independent wire rope core (IWRC) or strand core
protrusion between outer strands
• Obvious damage existing from any heat source
including
—
but not limited to—welding, power line strike,
or lightning
Reduction in the Rope Diameter
A reduction in rope diameter is often the first outward sign
that the rope core is damaged. Reduction in the rope
diameter can be caused by loss of core support, internal or
external corrosion, or wear of the outside wires.
New Wire Rope
—After initial loading, measure (see
Figure 5-26 ) and record the diameter of any new wire rope
for comparison to future inspections (see Maintain a Wire
Rope Condition Report on page 5-39 ).
The wire rope must be taken out of service when the
reduction from its nominal diameter is more than 5 percent.
Broken Rope Wires
When conducting the periodic comprehensive inspection,
thoroughly clean the wire rope so breaks can be seen. Relax
the rope, move it off “pick-up points,” and flex it as much as
possible to uncover damage. Use a sharp awl to lift any wire
which appears loose.
Do not attempt to open the rope
.
Wire breaks are typically at the crown of the strands—the
area that contacts the sheave or drum when a load is picked
up. Breaks at the crown will appear as small gaps in a wire.
In comparison, when wires in the valley of a strand break, the
broken ends will rise up and are easier to notice.
WARNING
Falling Load Hazard!
Replacement wire rope can break if it does not meet
Manitowoc Cranes specifications given in the following
publications supplied with your crane:
• Wire Rope Specifications Chart located in the
Capacity Chart Manual (for load lines)
• Boom or Jib Assembly drawings located in the
Operator Manual (for boom or luffing hoist)
• Mast Assembly drawing located in the Parts Manual
WARNING
Falling Load Hazard!
A broken wire indicates a weakened wire rope. Replace
wire rope when more than one broken wire appears.
Incorrect
Correct
Measuring Technique
FIGURE 5-26
Item Description
1 Lay Length: distance in which one strand makes one
complete revolution around core
2 Core
3 Strand
4 Wire
FIGURE 5-27
REFERENCE
ONLY