Manitowoc CD25, Руководство оператора, Страница: 115 / 160

6-5
CD25 MAINTENANCE
6
Published 1-06-2017 Control # 579-01
It is recommended that a periodic inspection of all boom
extension and retraction cables be performed using the
following guidelines. This inspection shall cover the entire
length of the extension and retraction cables. This inspection
should be used to monitor progressive degradation and to
discover severe damages necessitating wire rope
replacement or equipment repair. Inspection criteria are as
follows:
• Inspect for reduction of rope diameter below nominal
diameter.
• Inspect for severely corroded or broken wires at end
connections.
• Inspect for severely corroded, cracked, bent, worn, or
improperly applied end connections.
• Inspect wire rope in areas subjected to rapid
deterioration such as:
• Sections in contact with saddles, equalizer sheaves,
or other sheaves where wire rope travel is limited.
• Sections of wire rope at or near terminal ends where
corroded or broken wires may protrude.
• Sections of wire rope in contact with stationary
surfaces where abrasion or chafing may take place
as a result of equipment vibration.
• Inspect for damaged or wobbly boom extension and
retraction sheaves that may cause rapid deterioration of
the wire rope.
• Inspect for unusual cable sag/stretch and be sure cables
used in sets all have an equal tension applied. Repeated
need for adjustment of an individual cable is evidence of
cable stretch and indicates the need for additional and
more thorough inspection in order to determine and
correct the cause.
Wire Rope Inspection/Replacement (All Wire
Rope)
No precise rules can be given for determination of the exact
time for replacement of wire rope since many variable factors
are involved. Determination regarding continued use or
replacement of wire rope depends largely upon the good
judgement of an appointed and qualified person who
evaluates the remaining strength in a used rope after
allowance for any deterioration disclosed by inspection.
Wire rope replacement should be determined by the
following information excerpted from a National Consensus
Standard as referenced by Federal Government Agencies
and as recommended by Manitowoc. All wire rope will
eventually deteriorate to a point where it is no longer usable.
Wire rope shall be taken out of service when any of the
following conditions exist:
• In running ropes, six randomly distributed broken wires
in one lay or three broken wires in one strand in one lay.
• Wear of one-third 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.
• Reductions from nominal diameter of more than 5%.
• In standing ropes, more than two broken wires in one lay
in sections beyond end connections or more than one
broken wire at an end connection.
• In rotation resistant rope, two randomly distributed
broken wires in six rope diameters or four randomly
distributed broken wires in 30 rope diameters.
• Severe corrosion as evidenced by pitting.
• Manitowoc recommends that for cable extended booms,
a single damaged wire rope assembly shall require
replacement of the entire set of extension cables.
• Manitowoc recommends for cable extended booms, that
boom extension cables be replaced every seven (7)
years.
Seizing Wire Rope
It is important to seize the ends of rotation resistant wire
ropes to prevent the displacement and unraveling of the
individual wires and strands at the ends. All preformed and
non-preformed styles of wire rope should be seized prior to
cutting. Seizings must be placed on both sides of the point
where the wire rope is to be cut.
The two preferred methods for seizing wire ropes are:
Method 1
Using a length of soft annealed wire (Figure 6-3), place one
end in the groove between two strands of the wire rope. Turn
the long end of the annealed wire at right angles to the wire
and wrap it tightly over the portion in the groove.
The two ends of the annealed wire should be twisted
together tightly. Cut off the excess wire and pound the twist
flat against the wire rope.
Reference Only