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SANTERNO
USER MANUAL
quantity is 100%, the integral adjuster adjusts continuously through this time, and the adjustment amount reaches
the maximum frequency.
The output side of the process PI controller contains the default limit function to prevent the output value from
deviating from the normal value.
If the gain is positive, then the loop is positive effect loop; if the gain is negative, then the loop is negative loop. (for
the I or ID control with gain value 0.0, if set the integral time and differential time to be positive, then the loop is
positive effect loop; if set negative value, the loop will be negative effect loop).
Figure 6-2 Closed Loop Running Flow Chart
6.3 Synchronous Transfer Switch
By using the synchronizing switch technology, the VFD can be used to soft start and control multiple motors.
Synchronizing switch includes switch from the variable frequency to network frequency and switch from the
network frequency to variable frequency:
● VFD/Grid switch: Variable frequency to grid switch: VFD drives motor until the output frequency, amplitude, and
phase position are sync to grid, motor will be bypassed from VFD and running at grid frequency mode;
● Grid to variable frequency switch: motor running at grid frequency, VFD starts from no load and running until
sync switch to grid, VFD phase lock success and motor will run with VFD at variable frequency;
Control mode: Upper/ local/ remote
Set mode: Upper/ local/ remote
start
Adjust PI
Set the given parameter
Process close loop running flow chart is as following:
Close loop running
Close loop running
