FujiFilm Frenic-Mini Instruction Manual page 90

F09
Torque Boost
F37
Load Selection/Auto Torque Boost/Auto Energy Saving Operation
In general, there are two different properties of loads--the torque load which is in-
versely proportional to the square of speed (fans and pumps) and the constant
torque load (industrial machinery). You can select a V/f pattern optimized to the
load property.
Manual torque boost
In manual torque boost mode, the inverter maintains the output at a constant level
regardless of the load. When you use this mode, select the appropriate V/f pattern
(square reduction torque or constant torque characteristics) with Select Load
(F37). To keep the motor starting torque, manually select optimal inverter output
voltage for the motor and load by setting an optimal torque boost rate to F09 in
accordance with the motor and its load.
Setting an excessive torque boost rate may result in over-excitation and overheat
of the motor during light or no load operation.
Manual torque boost keeps the output voltage constant even if the load varies, as-
suring stable motor operation.
Variable torque characteristics (F37 = 0)
Automatic torque boost
This feature automatically optimizes the output voltage to fit the motor and its load.
Under a light load, it decreases the output voltage to prevent the motor from over-
excitation; under a heavy load, it increases the output voltage to increase torque.
Since this feature is related to the motor properties, it is necessary to set the rated
voltage at base frequency (F05) and motor parameters (P codes) properly.
• Set an appropriate torque boost rate that will keep the starting torque
of the motor within the voltage level in the low frequency zone. Set-
ting an excessive torque boost rate may result in over-excitation or
overheat of the motor during no load operation.
• The F09 data setting is effective when F37 (Load Selection/Auto
Torque Boost/Auto Energy Saving Operation) is set to 0, 1, 3, or 4.
For the automatic torque boost feature, which is related to the motor
characteristics, you need to consistently set the voltage at the base
frequency (F05) and motor parameters P02, P03 and P99 appropriately
for the motor rating and characteristics.
5-17
Constant torque characteristics (F37 = 1)