
3.SELECTING A MOTOR SPECIFICATIONS FOR THE βiS SERIES B-65302EN/01
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Overload duty characteristic
The percentage duty cycle indicates the ratio of the time during which
torque can be applied to the total time of a single cycle.
The ON time indicates the time during which the torque is being
applied.
Maximum cutting
torque
Tor q u e
Time
T
t
ON
OFF
ON : Time during which the maximum cutting torque is applied
OFF : Time during which no cutting torque is applied
Duty = (t/T)
×
100 [%]
ON time = t [minute]
Overload duty characteristics indicate the relationship between the
percentage duty cycle (%) and ON time (load time) in which the
motor can intermittently be operated with no temperature limit in the
range exceeding the continuous rated torque.
0
10
20
30
40
50
60
70
80
90
100
1 10 100 1000 10000
Torque percent
Limits by overheating
Indicated at intervals of
10 torque percent.
Limits by overcurrent alarms
Indicated at intervals of 10
torque percent.
Overload duty characteristic
Load time (sec.)
Duty (time %)
(ON time)
110%
120%
140%
170%
210%
MAX
Fig.3.4.1(b) Overload duty characteristic for β
ββ
β8/3000is