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Operating Instructions ACU
225
18.5.3.1
Torque preset
The reference torque can be specified as follows:
Set parameter
n-/M-Control Change-Over
164 to “6 - On” or link it to a digital signal and turn it on.
Select the torque preset source via parameter
Reference Percentage Source 1
476 or
Reference
Percentage Source 2
494.
For example:
The reference torque can be set via the arrow keys of the control panel if the following setting
is selected:
Reference Percentage Source 2
494
= “5 - KeyPad-Motorpoti” (factory setting).
The reference torque can be set via multifunction input 1 (MFI1A) if the following setting is
selected:
Reference Percentage Source 1
476
= “1 - Analog value MFI1A” (factory setting).
100 % torque refer to torque calculated from
Rated mech. power
376
(motor power) and
Rated Speed
372
(rated motor speed).
Parameter
Torque
224
shows the actual torque value.
Select setting of parameter
Operation Mode Search Run
645
according to the application. See
Chapter 13.5 "13.5".
18.5.3.2
Upper and lower frequency limit in torque control
In many situations, the speed must be limited at operating points with reduced or without load
torque, as the speed is adjusted according to the preset torque and the load behavior. To avoid
unwanted speeds (in most cases excessive speed, but sometimes low speeds, too, and to avoid
current impression), the speed is limited by the speed controller via
Frequency Upper Limit
767
and
Frequency Lower Limit
768
.
As from the limit, the speed is adjusted to the maximum (
Frequency Upper Limit
767
and
Frequency Lower Limit
768
) which corresponds to the behavior of the speed controller. In addition,
the controller limits the speed to the
Maximum Frequency
419
. This limitation is done by the speed
controller – changes of the speed controller affect the speed behavior in the limit range of the 3
parameters mentioned accordingly.
In current impression mode, the frequency is also limited to the
Minimum Frequency
418
– in direct
torque control mode, this limit is not active.
Parameter
Setting
No.
Description
Min.
Max.
Factory setting
767 Frequency upper limit
-599.00 Hz
599.00 Hz
599.00 Hz
768 Frequency lower limit
-599.00 Hz
599.00 Hz
-599.00 Hz
Positive values limit clockwise speed, negative values limit anticlockwise speed. If, for
example, both values are positive (> 0 Hz), anticlockwise operation will be disabled.
WARNING
If torque control is activated while the torsional frequency is outside the range
between
Frequency Upper Limit
767
and
Frequency Lower Limit
768
, (e.g. when a
machine is started from standstill or a quickly rotating machine is stopped quickly),
the permissible speed range will be approached without ramps by means of the
speed controller. In this case, the torque is only limited by the limitations of the
speed controller (current and torque). For this reason, there may be unexpected
dynamic behavior.
Summary of Contents for active cube 201
Page 1: ...ACTIVE CUBE Operating Instructions Frequency inverter 230 V 400 V 0 25 kW 132 kW...
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Page 45: ...12 16 Operating Instructions ACU 45...
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