4-2 Function Mode „ Torque Boost •Compensates for the voltage drop caused by the motor primary resistance or by wiring and suppresses torque reduction at a low speed range. Manual Torque Boost [A042/A242, A043/A243] •Adds the voltage characteristics set in A042/A242 and A043/A243 to the V/f characteristics, and outputs the resulting voltage. The addition value is set in percentage terms based on the AVR voltage selection (A082) as 100%. •The manual torque boost frequency (A043/A243) is set in percentage terms based on the base frequency as 100%. 4 Output voltage (100%) Manual torque boost voltage (A042/A242) Functions 0 Base frequency (A003/A203) Max.
frequency (A004/A204) Manual torque boost frequency (A043/A243) •If you raise the set value of the manual torque boost, be careful about motor overexcitation. Otherwise, the motor may burn out. •Should such a situation occur, lower the set value of A042/A242. Output frequency (Hz) Manual + Automatic Torque Boost (Intelligent Sensorless Vector Control) •Automatically adjusts output voltage and output frequency according to the load status. •To avoid a possible overcurrent trip during deceleration, set the AVR selection to "Always ON" (A081: 00). •Sufficient characteristics may not be obtained if you select two or more lower rank motor size than specified.
4-13 V/f characte Phenomenon Adjusting method Adjustment item Insufficient torque at low speed (Motor does not run at low speed.) Gradually increase the voltage setting of the manual torque boost. A042/A242 Gradually increase the slip compensation gain of the automatic torque boost. A047/A247 Gradually increase the voltage compensation gain of the automatic torque boost. A046/A246 Reduce the set value of the carrier frequency. b083 Rotation speed lowers when load is applied. Gradually increase the slip compensation gain of the automatic torque boost. A047/A247 Rotation speed increases when load is applied. Gradually reduce the slip compensation gain of the automatic torque boost.
A047/A247 Overcurrent trip occurs when load is applied. Gradually reduce the voltage compensation gain of the automatic torque boost. A046/A246 Gradually reduce the slip compensation gain of the automatic torque boost. A047/A247 Gradually reduce the voltage setting of the manual torque boost. A042/A242