7 - 11
7 Advanced Settings
High-function General-purpose Inverter RX2 Series User’s Manual
7-2 Selection of Motor Control Methods
7
7-2-5 Manual Torque Boost
Raise the output voltage by adding an extra voltage in order to achieve a higher torque at low speeds
than otherwise.
In the V/f control, no special correction is conducted to control the motor. Accordingly, at low output volt-
ages, the resistance component and/or the wiring in the motor will cause the voltage drop, which in turn
lowers the voltage applied to the motor. Manual boost corrects the voltage and thereby improves the
lowering of the torque at the low-speed range.
Confirm and adjust so that the output voltage of an inverter is within 150% level of the rated currents of
a motor.
As the manual torque boost value, 1st-motor [Hb141], set the proportion thereof to the async.Motor
rated voltage, 1st-motor [Hb106] (= 100 %). The set value is the maximum amount to be added at man-
ual torque boost Peak speed, 1st-motor [Hb142].
As the manual torque boost Peak speed, 1st-motor [Hb142], set the proportion of the frequency at that
point to the async.Motor Base frequency setting, 1st-motor [Hb104] (= 100%).
When an automatic torque boost is activated, you do not need to use the manual torque boost. Set the
manual torque boost when you do not use an automatic torque boost or a motor goes into a stall while
the deceleration.
e.g.) When [Hb140] = 02, the boost works only for the forward revolution of the motor.
Precautions for Correct Use
• Be sure not to cause an over excitation of the motor when raising the set value for the man-
ual torque boost. Boosting increases the flow of the current, which may burn the motor.
• The target of the torque boost is the V/f control of induction motors. (except the free V/f)
7-2-5 Manual Torque Boost
[Hb141]
[Hb142]
100
0
Output
voltage (%)
Forward-revolution
Base frequency
(100%)
Backward-
revolution
Output
frequency
Base frequency
(100%)
To Next Page
Loading...
