Technical information
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5
5.2.3
Starting torque >> OL(
n
max
) for constant torque load
It is possible to set the starting torque higher than the overload at maximum speed, i.e. OL(
n
base
) <
OL(
n
max
).
This can be useful when selecting the correct AC drive for constant torque drives where the starting
torque requirement is much higher than the maximum load requirement at maximum speed.
This possibility is usually used when the field weakening point is higher than base speed and when
the starting torque is needed for a very short time.
The benefit from this can be the possibility to use a size smaller AC drive.
Figure 46. Example: Starting torque >> OL(n
max
) for constant torque load
0
200
400
600
800
1000
1200
0
200
400
600
800
1000
1200
1400
1600
cont. load
max load
Speed [rpm]
To
rq
ue
[
N
m
]
13888_UK
