Wieland
podis
system
Manual V 1.03 / ref. no. 00.000.0059.0 / 28.03.2001
Max. speed
Adjustable value range (decimal) 1…255
Value range (physical variable)
0.25 Hz … 63.7 Hz
Factory setting
255
Recommended values
120 to 255
In the case of speeds below the nominal speed,
ensure that the motor is cooled sufficiently.
This parameter should for example be set to 200 if the connected drive
is to be operated with a maximum of 50 Hz. The frequency can be
increased and decreased in increments of 0.25 Hz. The motor speed is
then adjusted according to the number of poles and slip frequency.
Boost factor
Adjustable value range (decimal) 1…64
Value range (physical variable)
0%…25%
Factory setting
10
Recommended values
5…64
Used to increase the rotational torque (by increasing the voltage) at
low speeds.
U/f characteristic curve for podis MFI
U/U
nom
Boost factor (0…25% of nominal voltage)
At a nominal voltage of 400 V, the boost factor would be max. 100 V.
The U/f line starts with 100 V at 0 Hz and rises to 50 Hz at 400 V (see
U/f characteristic curve).
The voltage increase can be max. 25% of the nominal voltage e.g. at a
nominal voltage of 400 V, it would be 100 V. This leads to a better
torque curve in the lower speeds – the motor can accelerate at a faster
rate.
The boost factor influences the U/f characteristic curve of the
frequency inverter. When the motor is started, the motor voltage is
increased until the motor current exceeds the nominal motor current by
the figure indicated here.
CAUTION
Bild: (PDF)
Kennlin_MFI_U_vs_f_boost_01
