F43,F44
Current Limiter (Mode selection, Level)
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 limit the output
current. (Refer to the description of function code H12.)
If F43 = 1, the current limiter is enabled only during constant speed operation. If F43 = 2, the
current limiter 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.
The F44 setting value is converted from current braking operation level current I
imit
(A) based on reference current I
ref
(A). Set the value obtained from the following
conversion formula.
[Conversion formula]
Setting value
(%) = I
limit
(A)
×
100
I
ref
(A)
Example: If setting I
limit
(A) of 4.2 A with standard applicable motor capacity of 0.75 kW
Setting value
(%) = 4.2 (A)
×
100
=
84
5.0 (A)
Refer to the table for F20 to F22 for reference current.
Mode selection (F43)
F43 selects the motor running state in which the current limiter will be active.
Data for
F43
Running states that enable the current limiter
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.
• 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, specify a current limit
operation by hardware (H12 = 1) at the same time.
• If an excessive load is applied when the current limiter operation level is set
extremely low, the inverter will rapidly lower its output frequency. This may cause an
overvoltage trip or dangerous turnover of the motor rotation due to undershooting.
5-40
