Fuji Electric FRENIC-Ace series - Page 239

5.3 Description of Function Codes
5-69
FUNCTION CODES
Chap 5
When motor speed decreases during momentary power failure, and when restarting from frequency of before
momentary power failure after power is recovered (auto-restarting), current limiter becomes active and output
frequency of the inverter decreases automatically. When output frequency and motor rotation speed synchronize,
the speed is accelerated up to the original output frequency. Refer to the figure below. However, it is necessary to
enable instantaneous overcurrent limiting (H12 = 1) to bring in synchronization of the motor.
• Auto-restarting after momentary power failure “IPF”
During momentary power failure auto-restarting “IPF” signal is turned on until returning to original frequency after
auto-restarting after momentary power failure occurred. When “IPF”: is turned ON, motor speed decreases,
therefore, take necessary measures. ( Function code E20, E21, E27 Data = 6)
■ Restart mode after momentary power failure (Basic operation: With auto-searching setting)
Auto-searching is not performed normally if there is residual voltage of the motor.
Therefore, it is necessary to secure the time until residual voltage runs out.
Restart mode after momentary power failure secures the necessary time with function code H46 starting mode
(auto search delay time 2). Even if starting conditions are satisfied, inverter does not start unless auto-search delay
time elapses after inverter goes into OFF state. Inverter starts after elapse of auto-searching delay time.
( Function code H09, d67)
• When operating auto-searching, it is necessary to perform auto-tuning in advance.
•
When the estimated speed exceeds the maximum frequency or the upper limit frequency, the inverter
disables auto search and starts running
the motor with the maximum frequency or the upper limit
frequency, whichever is lower.
•
During auto search, if an overcurrent or overvoltage trip occurs, the
inverter will restart the auto
search.
•
Use 60 Hz or below for auto-searching
•
Note that auto
search may not fully provide the performance depending on load conditions, motor
parameters, wiring length, and other external factors.
•
When output circuit filter OFL--2, -
4 is equipped on the output side of the inverter,
auto-searching must be disabled. Use OFL--A type.
Power
failure
Power
restoration
DC link bus
voltage
Undervoltage
Output frequency
(motor rotational speed)
Auto-restarting after
momentary power failure IPF
Synchronization
Acceleration
Time
Time
Time
Power
restoration
Power
failure
DC link bus
voltage
Motor speed/output
frequency
Output frequency
Motor speed
F14 = 4