10. Advanced functions
H23: It limits the current during Speed search. Set as the percent of H33 – [Motor rated current].
H24, H25: Speed search is activated via PI control. Adjust P gain and I gain corresponding to the load characteristics.
I54, I55: Signal of active Speed search is given to external sequence via
EX) Speed search during Instant Power Failure restart
Input |
|
voltage |
|
Frequency |
|
t1 | t2 |
Voltage |
|
H23 |
|
Current |
|
| |
output or |
|
Relay |
|
When the input power is cut off due to instant power failure, the inverter outputs Low voltage trip (LV) to hold the output.
When the power is restored, the inverter outputs the frequency before the low voltage trip and the voltage is increased due to PI control.
t1: If the rise in current is greater than the preset level in H23, the rise in voltage will stop and the frequency is decreased.
t2: If the opposite of t1 occurs, the increase in voltage starts again and the decrease in frequency stops.
When the frequency and voltage are restored back to the nominal level, acceleration will continue at the frequency before trip.
Speed search is suitable operation when load inertia is large. It is highly recommended to restart after stopping the motor when the load inertia is great.
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