COMEUP Electric Winch (Ver:02) - Manual (Page 7)

III. Winching Principles
5
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 continuous ratings.
Continuous ratings means the percentage duty cycle (%ED) is subject to the rated voltage,
rated frequency and a 63% of rated load.
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.
For this reason, all electric winches are rated at a 25% percentage duty cycle (%ED).
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 electric winches are rated at their
top layer of wire rope on the drum.
Calculating Head Loads
Use a tackle block for double fall operation to increase the rated load by approximately
85% but its speed will be deducted by half accordingly.
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