Omron JX-A4004, User Manual, Page: 94 / 220

4-16
4-2 Function Mode
4
Func
tions
Special Reduced Torque Characteristics (Special VP)
•Suitable for a fan or pump that requires torque in a low speed range using VC characteristics at
this area..
Period a Provides constant torque characteristics (VC) within a range from 0 Hz to 10% of base
frequency. (Example) If the base frequency is 50 Hz, the Inverter provides constant torque
characteristics within a range from 0 to 5 Hz.
Period b Provides reduced torque characteristics within a range from 10% to 100% of the base fre-
quency.
The Inverter outputs voltage based on a curve of the 1.7th power of the frequency.
Period c Provides constant voltage within a range from the base frequency to the maximum fre-
quency.
„
Torque Boost
This function helps to compensate insufficient motor torque in a low speed range.
•Compensates the voltage drop caused by the primary resistance of the motor or wiring increasing
the torque in low speed range.
•To select the simple torque boost in the torque boost selection (A041/A241), set the motor capacity
selection (H003/H203) and motor pole number selection (H004/H204) according to your motor.
Manual Torque Boost [A042/A242, A043/A243]
•Adds the voltage 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%.
•If you raise the set value of the manual torque boost (A042/A242) be careful about motor
overexcitation. Otherwise the motor may burn out.
Simple Torque Boost [A041/A241]
•If simple torque boost is selected in the torque boost selection (A041/A241: 01), it operates to
adjust the output voltage depending on the load level.
•To select simple torque boost in the torque boost selection (A041/A241), set the motor capacity
selection (H003/H203) and motor pole number selection (H004/H204) according to your motor.
•You may avoid a possible overcurrent trip during deceleration by always setting the AVR selection
to ON (A081: 00).
•Sufficient characteristics may not be obtained if you select two or more lower rank motor size than
specified.
0
Output
voltage
(100%)
Base frequency
(A003/A203)
Output
frequency (Hz)
Max. frequency
(A004/A204)
VC
VP
(1.7th power)
10% of base
frequency
a b c
0
Output
voltage (100%)
Manual torque
boost voltage
(A042/A242)
Manual torque boost
frequency (A043/A243)
Base frequency
(A003/A203)
Max. frequency
(A004/A204)
Output frequency (Hz)
V/f characteristics
(Example: VC)