10.2.5
I/F START FUNCTION
When you have a PM motor, use the I/f Start function to start the motor with constant current
control. You can receive the best effect with a high power motor. With a high power motor,
the resistance is low and it is not easy to change the U/f curve.
The I/f Start function can also give a sufficient torque for the motor at startup.
C
B
D
A
[s]
Fig. 25: The I/f start parameters
A. I/f Start Current
B. Output Frequency
C. Motor Current
D. I/f Start Frequency
P3.1.4.12.1 I/F START (ID 534)
Use this parameter to enable the I/f Start function.
When you activate the I/f Start function, the drive starts to operate in the current control
mode. A constant current is led to the motor until the output frequency increases above the
level that is set in P3.1.4.12.2. When the output frequency increases above I/f Start
Frequency level, the operation mode changes back to the normal U/f control mode.
P3.1.4.12.2 I/F START FREQUENCY (ID 535)
Use this parameter to set the output frequency limit below which the set I/f start current is
fed to motor.
When the output frequency of the drive is below the limit of this parameter, I/f Start function
activates. When the output frequency is more than the limit, the drive operation mode
changes back to the normal U/f control mode.
P3.1.4.12.3 I/F START CURRENT (ID 536)
Use this parameter to set the current that is used when the I/f Start function is enabled.
PARAMETER DESCRIPTIONS
VACON · 209
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