Chapter 4
Explanation of Functions
4-18
4.2.18 Torque boost setting
The torque boost setting function allows you to compensate for the
voltage drop due to wiring and the primary resistance of the motor
so as to improve the motor torque at low speeds.
When you select automatic torque boost by the torque boost
selection (A041/A241), adjust the settings of the motor capacity
selection (H003/H203) and motor pole selection (H004/H204)
based on the motor to be driven.
Item
Function code
Data or range of data
Description
Torque boost selection
A041/A241
00
Manual torque boost
01
Automatic torque boost
Manual torque boost value
A042/A242/A342
0.0 to 20.0(%)
Setting of the rate of the boost to the
output voltage (100%)
Manual torque boost frequency
adjustment
A043/A243/A343
0.0 to 50.0(%)
Setting of the rate of the frequency at
breakpoint to the base frequency
Motor capacity
H003/H203
0.20 to 75.0(kW)
Selection of the motor capacity
Motor poles setting
H004/H204
2, 4, 6, 8, or 10 (poles)
Selection of the number of poles of the
motor
Voltage compensation gain
setting for automatic torque
boost
A046/A246
0. to 255.
See Item (2), "Automatic torque
boost."
Slippage compensation gain
setting for automatic torque
boost
A047/A247
0. to 255.
See Item (2), "Automatic torque
boost."
(1) Automatic torque boost
The inverter outputs the voltage according to the settings of the manual torque boost (A042/A242/A342) and manual
torque boost frequency adjustment (A043/A243/A343).
Use the manual torque boost value (A042/A242/A342) to specify the rate of the boost to the voltage (100%) set by the
AVR voltage select.
The set rate of voltage corresponds to the boost voltage that is output when the output frequency is 0 Hz.
When increasing the value of the manual torque boost value, be careful to prevent motor over-excitation.
Over-excitation may result in motor burnout.
Use the manual torque boost frequency adjustment (A043/A243/A343) to specify the rate of the frequency at each
breakpoint to the base frequency (100%).
To switch the settings among the 1st, 2nd, and 3rd settings ("A041 to A043", "A241 to A243", and "A342 and A343"),
assign function "08" (SET) and "17" (SET3) to intelligent input terminals. Use the SET and SET3 signals for switching.
A042/A242/A342
A043/A243/A343
100
Output voltage (%)
Base frequency
(100%)
Output
frequency
A041/A241: Torque boost selection, 1st/2nd motors
A042/A242/A342: Manual torque boost value,
1st/2nd3rd motors
A043/A243/A343: Manual torque boost frequency
adjustment, 1st/2nd/3rd motors
H003/H203: Motor capacity, 1st/2nd motors
H004/H204: Motor poles setting, 1st/2nd motors
Related code
Summary of Contents for SJ700D-004L
Page 16: ...Contents Appendix Appendix A 1 Index Index Index 1 ...
Page 44: ...Chapter 2 Installation and Wiring 2 23 Memo ...
Page 70: ...Chapter 3 Operation 3 25 Memo ...
Page 248: ...Chapter 5 Error Codes 5 11 Memo ...
Page 256: ...Chapter6 Maintenance and Inspection 6 7 Memo ...