KFU 2-/4-
187
If the output current has already been reduced due to the fact that the long-term over-
load has used up, the short-term overload is no longer available even if it has not
been used up beforehand. The defined overload reserve (Ixt) of the frequency in-
verter is available again after a power reduction lasting 10 minutes.
Output signals
Digital outputs can signalize the achievement of a limit value – selected in
Operation
Mode
573
.
15 - Warning Current Limitation Intelligent Current Limits active. Output current
is limited.
16 - Controller Current Limit.
Long Term Ixt
The overload reserve for 60 s has been used up
and the output current is being limited.
17 - Controller Current Limit.
Short Term Ixt
The overload reserve for 1 s has been used up
and the output current is being limited.
18 - Controller Current Limit. Tc Intelligent Current Limits active. Maximum heat
sink temperature Tc reached.
19 - Controller Current Limit.
Motor Temp.
Intelligent Current Limits active. Maximum mo-
tor temperature reached.
16.2 Voltage
controller
The voltage controller contains the functions necessary for monitoring the DC link
voltage.
The DC link voltage which rises in generator operation or in the braking process
of the 3-phase machine is controlled to the set limit value by the voltage control-
ler.
The power failure regulation uses the rotation energy of the drive to bridge short-
term power failures.
The voltage controller is set with the parameter
Operation Mode
670
in accordance
with the application.
Operation Mode
670
Function
0
-
Off
The function is switched off.
1
-
Udc-Limitation active
Overvoltage controller switched on,
with motor chopper. Factory setting.
2
-
Mains Support active
Power failure regulation switched on,
with motor chopper, for quick shutdown.
3
-
Udc-Limit. & Mains
Supp. active
Overvoltage controller and power failure regulation
switched on, with motor chopper.
12
-
Mains Support active,
Chopper not active
Power failure regulation switched on,
without motor chopper.
13
-
Udc-Limit. & Mains
Supp. active, Chopper
not active
Overvoltage controller and power failure regulation
switched on, without motor chopper.
The function motor chopper is available in the field-oriented control methods (in con-
figurations 210, 230, 410, 411 and 430).
When an operation mode with motor chopper is selected, set the
Trigger thresh-
old
507
to the
Reference UD limitation
680
.
