Toshiba TOSVERT VF-nC3 Instruction Manual page 101

3) Increasing starting torque
Setting of V/F control mode selection  to  (automatic torque boost control)
Detects load current in all speed ranges and automatically adjusts voltage output (torque boost) from inverter.
This gives steady torque for stable runs.
Base frequency voltage
:Automatically
adjusts the
amountof torque
boost.
Note: This control system can oscillate and destabilize runs depending on the load. In this case, set
V/F mode selection = (V/F constant) and increase manual torque boost .
Motor constant must be set
If the motor you are using is a 4P Toshiba standard motor and if it has the same capacity as the inverter,
there is basically no need to set the motor constant. In any other case, set the following parameters
according to the motor's name plate.
 (base frequency 1),  (base frequency voltage 1),  (motor rated capacity),  (motor
rated current),  (motor rated speed)
Be sure to set  (rated current of motor) and  (rated speed of motor) correctly, as specified on
the motor's nameplate. For the setting of  (no-load current of motor), refer to the motor test report.
There are three procedures for setting the other motor constants.
1) Auto torque boost and a motor constant (auto-tuning) can be set at once.
To do so, set the basic parameter  to .
2) The motor constant can be automatically set (auto-tuning).
Set the extended parameter  to .
3) Each motor constant can be set individually.
4) Vector control - increasing starting torque and achieving high-precision operation.
Setting of V/F control mode selection  to 3 (Vector control)
Using sensor-less vector control will provide the highest torque at the low speed ranges.
(1) Provides large starting torque.
(2) Effective when stable operation is required to move smoothly up from the low speeds.
(3) Effective in elimination of load fluctuations caused by motor slippage.

0
Base frequency 
⇒For details, see 1 in 5.2.
⇒ For details, see 6.14, selection 2.
⇒ For details, see 6.14, selection 3.
E-19
E6581595
Output frequency (Hz)
5