Motor Controllers AC Variable Frequency Drives
RVBS
Specifications are subjected to change without notice.10/08/2021
35
inverter at full capability during acceleration and to limit the output current during constant speed operation.
F26 specifies the output current level to determine whether to limit the output current. The function code data
should be set, assuming the rated output current of the inverter as 100%, in increments of 1%.
[Conversion formula]
𝑆𝑒𝑡𝑡𝑖𝑛𝑔 𝑣𝑎𝑙𝑢𝑒 (%) =
𝐼
𝑙𝑖𝑚𝑖𝑡
(𝐴)
𝐼
𝑟𝑒𝑓
(𝐴)
∗ 100
➢
Example: If setting I
limit
(A) of 4.2 A with standard applicable motor capacity of 0.75 kW
𝑆𝑒𝑡𝑡𝑖𝑛𝑔 𝑣𝑎𝑙𝑢𝑒 (%) =
4.2 (𝐴)
5.0 (𝐴)
∗ 100 = 84
-
Mode selection (F25)
F25 selects the motor running state in which the current limiter will be active.
Data for
F25
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 (F26)
F26 specifies the operation level at which the output current limiter becomes activated, in ratio to the
inverter rating.
➢
Note: Since the current limit operation with F25 and F26 is performed by software, it may cause a delay in
control. If you need a quick response, specify a current limit operation by hardware (H07 = 1) at the same
time.
➢
Note: 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
Function
code
Mod.
add.
Description
Def
Min
Max
U.M.
R/W
F25
0x0019
Current Limiter (Mode selection)
2
0
2
-
R/W
F26
0x001A
Current Limiter (Level)
180
20
200
%
R/W
4.4.2
Instantaneous over-current limitation
H07 specifies whether the inverter invokes the current limit processing or enters the over-current trip
when its output current exceeds the instantaneous over-current 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.
