8.6.3
Adjustment of the U/f curve
Information
The device comes supplied with a preprogrammed square characteristic curve for the operation of
fans.
In the case of voltage-controllable motors and square load torque-moments (e.g. fans and pump
operation), an optimal speed control is generally achieved through this.
In systems in which high dynamics are required, switchover to a linear characteristic must take place.
Generally speaking, if the load characteristic is not known as a de
fi
nite value, the linear characteristic
should be set. In the case of linear characteristic curves, the motor achieves full torque throughout the
entire speed range. For this, a thermal overload of the motor must be prevented through suitable
measures (complete motor protection through using thermocontact or PTC thermistor-monitoring).
Edgefrequency
Edgefrequency
The maximum output voltage is attained during break edge frequency.
Adjustment range: 1.0 - 120.0 Hz
Factory setting: 48.5 Hz
In the case of special settings with
“
Edge frequency
”
>
“
Max. Frequency
”
, due to higher
power losses it is possible that automatic power reduction occurs (
Messages and
trouble shooting
“
Temp. Manager
”
).
Max. Frequency
Max. Frequency
Above the Edgefrequency, the frequency is merely increased up to the Maximum
frequency.
Adjustment range: 1.0 - 120 Hz
Factory setting: 50.0 Hz
F
out
[Hz]
F
max
= 50 Hz
F
off
26.07.2012
v_u_f_dia_fcontr_d.vsd
1
2
3
4
5
6
7
8
9
10
Analog In 1
0
45
50
40
35
30
25
20
15
10
5
2
4
6
8
10
12
14
16
18
20
0...10 V
0...20 mA
10
20
30
40
50
60
70
80
90
100 0...100 % PWM
F
edge
= 48.5 Hz
U
out
100 %
F
on
0.5
1
5
Q
L
U
start
= 10 %
U
start
= 0 %
Uout
Output voltage
Fout:
Output frequency
Analog In
Speed setting signal (0 - 10 V, 0...20 mA, 0...100 % PWM)
Ustart
Startvoltage
Foff
Shutdown Freq.
Fon:
Switch on Freq.
Fedge
Edgefrequency
Fmax
Max. Frequency
L
linear
Q
Square (factory setting)
Due to technical reasons the output voltage amounts to approx. max. 95 % of the applied mains
voltage.
In order to still be able to achieve the maximum air
fl
ow of the connected fans, an increase of the
maximum frequency is possible for our motors. For this, a current increase must be included in the
calculation. It is necessary to optimize monitoring of motor current, output voltage, and speed using
suitable measuring instruments.
Operating Instructions
Fcontrol Basic
–
model series FSDM2.5..50AM
Programming
L-BAL-E174-GB 1704 Index 005
Part.-No.
31/49
