COMEUP Baby Winch (Ver:03) - Manual (Page 9)

III. Winching Principles
7
Percentage Duty Cycle
Load Rated
The life of the winch is depending on the conditions of the load and working frequency.
In the long time operation, make sure to use the machine within its short time ratings.
Short time ratings means the working duty cycle (%ED) is subject to the rated voltage, rated
frequency and a 63% of rated load. All baby winches are rated 25% percentage duty cycle (%ED).
Percentage duty cycle (%ED) X 100 (%)
Tb: total sum of overall loadings operating hours.
Ts: total sum of stopping hours.
Tb + Ts = approximately 1 to 10 minutes.
Load and speed vary according to how
much wire rope is on the drum. The first layer
of rope on the drum delivers the slowest speed
and the maximum load. A full drum delivers the
maximum speed and the minimum load. For
this reason, all CWS winches are rated at their
top layer of wire rope on the drum.
Use a tackle block for double line operation,
to increase line pull by approximately 85% but its speed will be deducted by half accordingly.
Calculating Head Loads
P: Rope tension
η: Sheave efficient
θ: Angle
W: Load
μ: Friction factor
！
WARNING
Never hoist over the rated percentage duty cycle.
First layer (Min.speed Max.load)
Half layer (Med.speed Med.load)
Top layer (Max.speed Min.load)
Flange of drum
P
W
P= W η
P
W
P= W
2
η
P
P= W
4
η
W
P
W
P= W
μ .
μ
P
μ
W
θ
P= W
μ . .
sinθ + W
.
cosθ
Tb
Tb + Ts