09/01 AWB8230-1412GB
Current limit
99
Current limit
With the current limit parameter, the motor current can be limited.
To reduce the load current, the frequency rise ends in the accele-
ration phase or the output frequency is reduced in the static phase,
as soon as the output current exceeds the set current limit. The
time constant for control at the current limit is entered under
PNU b23. As soon as the output current drops below the set
current limit, the frequency increases again to the configured
setpoint value. The current limit can be switched off for the acce-
leration phase (a PNU b21), to allow higher currents to flow for
a brief period.
Figure 94: Current limit
I
M
: motor current
I
1
: current limit
Caution!
Note that the current limit cannot prevent a fault message
and shutdown due to a sudden overcurrent (e.g. caused
by a short-circuit).
I
1
PNU b23 PNU b23
f
I
t
PNU Name Adjustable in
RUN mode
Value Function WE
b21 Current limit
characteristic
– 00 Motor current limit not active 01
01 Motor current limit active in all operating states
02 Motor current limit not active during acceleration
b22 Tripping
current
– 0.5 to 1.5 x I
e
Setting range of the tripping current as a multiple of the frequency
inverter rated current, i.e. the range is given in amperes (A).
1.25 x I
e
1)
b23 Time constant – 0.1 to 30 Hz/s When the set current limit is achieved, the frequency is reduced in
the time set here.
Caution: If possible, do not enter a value less than 0.3 here!
1.0
1) Inverter rated current
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