Function Applications
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Figure 4-35 User-defined multi-point V/f curve
The multi-point V/f curve is defined by F3-03 to F3-08. The range of the frequency points is 0.00 Hz to
the rated motor frequency. The range of the voltage points is 0.0% to 100%, which corresponds to the
range of 0 V to the rated motor voltage. The multi-point V/f curve references are typically determined
based on load characteristics of the motor. Ensure that the following conditions are met: F3-03 ≤ F3-
05 ≤ F3-07. To ensure correct setting, this AC drive has restrictions on the relationship between the
upper and lower limits of the frequency points F3-03, F3-05, and F3-07. F3-07, F3-05, and F3-03 must be
set in order.
Square V/f Curve
The following figure shows the variable-torque square V/f curve.
Figure 4-36 Variable-torque square V/f curve
Below the rated frequency, the output voltage changes with the output frequency of the AC drive
according to the 2-power curve. This curve is applicable to applications with light loads that seldom
change, such as fans and water pumps.