F09
Torque Boost1
F37
Load Selection/Auto Torque Boost
F37 specifies V/f pattern, torque boost type for optimizing the operation in accordance
with the characteristics of the load. F09 specifies the type of torque boost in order to
provide sufficient starting torque.
Data for
F37
V/f pattern
Torque boost
(F09)
Auto energy
saving
Applicable load
0
Variable
torque V/f
pattern
Torque boost
specified by
F09
Disable
Variable torque load
(General purpose fans and pumps)
1
Linear
V/f pattern
Constant torque load
2
Auto torque
boost
Constant torque load
(To be selected if a motor may be
over-excited at no load.)
Note: If a required "load torque + acceleration toque" is more than 50% of the rated
torque, it is recommended to select the linear V/f pattern (factory default).
V/f characteristics
The FVR-Micro of inverters offers a variety of V/f patterns and torque boosts, which
include V/f patterns suitable for variable torque load such as general fans and pumps or
for special pump load requiring high starting torque. Two types of torque boost are
available: manual and automatic.
Variable torque V/f pattern (F37 = 0)
Linear V/f pattern (F37 = 1)
When the variable torque V/f pattern is selected (F37 = 0), the output voltage
may be low and insufficient voltage output may result in less output torque of
the motor at a low frequency zone, depending on some characteristics of the
motor itself and load. In such a case, it is recommended to increase the output
voltage at the low frequency zone using the non-linear V/f pattern (H50, H51).
Recommended value: H50 = 1/10 of the base frequency
H51 = 1/10 of the voltage at base frequency
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