Simphoenix V800 Series - Page 127

Description Of Specific Functions
119
V800 Series High Performance Closed-Loop Vector Inverter User Manual
Time
Frequency
[F1.2.15]
[F0.4.39]
[F0.4.40]
F0.4.41 Start pre-excitation current
Setting range: 0.0~100%
Factory default: 35.0
F0.4.42 Start pre-excitation time
Setting range:
0.00~10.00Sec.
Factory default: 0.10
It costs some time to develop air gap flux for asynchronous motor (approaching to the constant of the rotor
time). When it is at stop status before the motor is started, in order to get enough start torque, it is a must to
develop the air gap flux. Therefore, it is needed to start pre-excitation for the asynchronous motor. See
Figure 7-18 for the pre-excitation process.
The set value of start pre-excitation current is the percentage with respect to the inverter rated output current.
The start pre-excitation time means the duration in which the inverter inputs start pre-excitation current for
the motor.
Figure 7-17 Start frequency sketch
Figure 7-18 Start pre-excitation output

When the rated current of the adapter motor differs greatly from the rated current of the
inverter, please carefully set the pre-excitation current (F0.4.41), as excessive setting may
damage the motor.