Comeup CWL-301L, Instruction Manual

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III. Handling Precautions And Calculations
Handling Precautions
The operator of winch in some cases is required for qualifications according to
applicable laws and ordinances.
Prior to starting of use, carry out the daily checking without fail, and use after
confirming the safety of function.
Don't use exceeding the lead rated.
The operator of winch must not be apart from the operating position under the
loading condition.
Carry out the operation of lifting and lowering after stopping the winch once, and
avoid the rapid speed operation as far as possible.
Even in the condition where the rope is feed out at most, the rope must remain by
five more windings on the drum.
Record the daily operating time and take into consideration so as to obtain the
suitable time for intermediate inspection and arrangement.
Calculating Head Loads
P: Rope tension
η
: Sheave coefficient
θ
: Angle
W: Load
μ
: Friction factor
Calculating Fleet Angle
The winch should be mounted as close to center and as perpendicular as possible to
the direction of the line pull. This will keep the wire rope fleet angle centered on the
drum as small as possible.
If the proper fleet angle is not maintained, the wire rope could wind onto one side
of the drum. This could cause failure of the winch or wire rope, resulting in damage,
injury or death.
Experience has shown that the best wire rope service is obtained when the
maximum fleet angle is not more than 1.
5°
∘
for smooth drums.
The distance from centre of the rope drum till the first rope sheave or roller fairlead
shall in the ideal case be 19 times the drum width