6
5
KEB COMBIVERT F4-C
4
Name: Basis
28.01.98
©
KEB Antriebstechnik, 1997
All Rights reserved
Adjustment U/f-Characteristic
Functional Description
Chapter
Section
Page
Date
250 V
CP.17 = 230 V
190 V
CP.5 = 50 Hz
f
U
N
/U
A
uF.8 = 230V
uF.0 = 50Hz
UA
t
uF.1
100%
uF.5
uF.4
uF.4 = 0,0...25,5 %; Default = 0 %
uF.5 = 0,0...10,0 s; Default = 0 s
6.5.4
Delta Boost
(uF.4/uF.5)
The Delta-Boost is a time-limited Boost, which is used to overcome large breakaway
torques. The Delta-Boost acts adding to the Boost, however, the sum is limited to
25.5 %.
6.5.5
UZK-
Compensation
(uF.8)
Through fluctuations of the mains voltage or the load the DC-link voltage can change
and with it the directly dependent output voltage. At activated DC-link (UZK)
compensation the fluctuations of the output voltage are balanced. This means 100 %
output voltage correspond to the value adjusted in uF.8, but maximum 105% -
(UZK /
√
2). The function also allows the adaption of motors with smaller rated voltage
to the inverter.
uF.8 = 1...649 V
650 = off (default)
Picture 6.5.4
Delta Boost
Picture 6.5.5.a
UZK-Compensation
with UZK-compensation
without UZK-compensation
Picture 6.5.5.b
Example: Acceleration with load
actual Load
actual Load
Motor voltage
Motor speed
Motor voltage
Motor speed
U
A
at U
N
= 250V unstabilized
U
A
at U
N
= 190V unstabilized
U
A
at U
N
= 190V stabilized
U
A
at U
N
= 250V stabilized
Example: uF.8 = 230V
no boost adjusted
U
N
= Mains voltage
U
A
= Output voltage