8000m Series
- 117 -
Setting Options
110~150%
FA.04: As in deceleration process of VFD, by the influence of load inertia, the
motor speed’s deceleration rate might be lower than the frequency reducing rate,
thus it results in power regeneration to VFD by motor and bus voltage increasing.
In some cases with no measure being carried out, it will put the VFD to over
voltage fault due to high bus voltage finally.
For 220V single phase VFD the value of parameter Over-voltage stalling
protection point FA.05 is 120%, and for 380V three-phase VFD this value of
FA.05 is 130%.
The principle of over-voltage stalling protection is as following: By sensing bus
voltage and comparing to FA.05 (relative to standard bus voltage) which defining
the over-voltage stalling point, if the bus voltage is over the point, VFD will stop
decreasing output frequency, and will keep running in current frequency until the
bus voltage falling to lower than the point. And then VFD will continue to
decelerate the motor again. As shown in the following illustration.
