SJ700-2 Instruction Manual NT204DX - Hitachi America, Ltd.

Chapter 4 Explanation of Functions
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.
Related code
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
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
Setting of the rate of the frequency
A043/A243/A343 0.0 to 50.0(%)
adjustment
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
See Item (2), "Automatic torque
setting for automatic torque A046/A246 0. to 255.
boost."
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.
Output voltage (%)
100
A042/A242/A342
A043/A243/A343
Base frequency
(100%)
Output
frequency
4 - 18