Hitachi L700 SERIES Instruction Manual page 81

(2) Automatic torque boost
When automatic torque boost (data "01") is selected by the torque boost selection (A041/A241), the
inverter automatically adjusts the output frequency and voltage according to the load on the motor.
(During actual operation, the automatic torque boost is usually combined with the manual torque boost.)
When you select the automatic torque boost, adjust the settings of the motor capacity selection
(H003/H203) and motor pole selection (H004/H204) according to the motor to be driven.
If the inverter trips due to overcurrent during motor deceleration, set the AVR function select (A081) to
always enable the AVR function (data "00").
If you cannot obtain the desired operation characteristic by using the automatic torque boost, make the
following adjustments:
Symptom
Motor torque is insufficient at low
speed.
(The motor does not rotate at low
speed.)
The motor speed falls when a load
is applied to the motor.
The motor speed increases when a
load is applied to the motor.
The inverter trips due to overcurrent
when a load is applied to the motor.
This function cannot be selection for 3rd moter setting.
Manual torque boost valid.
Adjustment method
(1) Increase the voltage setting for manual torque boost
step by step.
(2) Increase the slippage compensation gain for
automatic torque boost step by step.
(3) Increase the voltage compensation gain for
automatic torque boost step by step.
(4) Reduce the carrier frequency setting.
Increase the slippage compensation gain for the
automatic torque boost step by step.
Reduce the slippage compensation gain for the
automatic torque boost step by step.
(1) Reduce the voltage compensation gain for the
automatic torque boost step by step.
(2) Reduce the slippage compensation gain for the
automatic torque boost step by step.
(3) Reduce the voltage setting for the manual torque
boost step by step.
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Chapter 4 Explanation of Functions
Adjustment item
A042/A242
A047/A247
A046/A246
b083
A047/A247
A047/A247
A046/A246
A047/A247
A042/A242