Hitachi SJ700-2 instruction manual Torque boost setting

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	A043/A243/A343	0.0 to 50.0(%)	Setting of the rate of the frequency
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	A047/A247	0. to 255.	See Item (2), "Automatic torque
setting for automatic torque
			boost."
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	Output
	(100%)	frequency

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