Fuji Electric FRENIC-AQUA series, User Manual

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F43, F44 Current Limiter (Mode selection and Level)
H12 (Instantaneous Overcurrent Limiting, Mode selection)
When the output current of the inverter exceeds the level specified by the current limiter
(F44), the inverter automatically manages its output frequency to prevent a stall and limits the
output current. The default of the current limiter level is 120%. Do not change the factory
default except when necessary.
The current limiter mode is selected with F43. If F43 = 1, the current limiter is enabled only
during constant speed operation. If F43 = 2, it is enabled during both of acceleration and
constant speed operation. Choose F43 = 1 if you need to run the inverter at full capability
during acceleration and to limit the output current during constant speed operation.
„ Mode selection (F43)
F43 selects the motor running state in which the current limiter becomes activated.
Running states that enable the current limiter
Data for
F43
During acceleration During constant speed During deceleration
0 Disable Disable Disable
1 Disable Enable Disable
2 Enable Enable Disable
„
Level (F44)
F44 specifies the operation level at which the output current limiter becomes activated, in
ratio to the inverter rating.
- Data setting range: 20 to 120 (%) (in ratio to the inverter rating)
„
Instantaneous Overcurrent Limiting (Mode selection) (H12)
H12 specifies whether the inverter invokes the current limit processing or enters the
overcurrent trip when its output current exceeds the instantaneous overcurrent limiting level.
Under the current limit processing, the inverter immediately turns OFF its output gate to
suppress the further current increase and continues to control the output frequency.
Data for H12 Function
0 Disable
An overcurrent trip occurs at the instantaneous overcurrent limiting level.
1 Enable
If any problem could occur when the motor torque temporarily drops during current limiting
processing, it is necessary to cause an overcurrent trip (H12 = 0) and actuate a mechanical
brake at the same time.
• Since the current limit operation with F43 and F44 is performed by software, it
may cause a delay in control. If you need a quick response current limiting, also
enable the instantaneous overcurrent limiting with H12.