WEG CFW300 V1.3X, Programming Manual

Page: 66 / 157

V/f Scalar Control
9-4 | CFW300
9
P136 - Manual Torque Boost
Adjustable
Range:
0.0 to 30.0 %
Factory
Setting:
5.0 %
Properties: V/f
Description:
It actuates at low speeds, that is, in the range 0 to P146 (V/f) or 0 to P145 (Quadratic V/f), increasing the inverter
output voltage so as to compensate the voltage drop in the motor stator resistance in order to keep the torque
constant.
The optimum setting is the smallest value of P136 which allows the motor satisfactory start. A value greater
than necessary will excessively increase the motor current at low speeds, which may lead the inverter to a fault
condition (F051 or F070) or alarm condition (A046 or A050), as well as motor overheating.
Figure 9.4 on page
9-4 and Figure 9.5 on page 9-4 show the actuation regions of the Torque Boost for the V/f and Quadratic
V/f mode, respectively.
P134 P145 P146
P
0
P
1
P
2
P
3
P142
P143
P136
Output
frequency (Hz)
Output
voltage (%)
Figure 9.4: Torque boost region for V/f control mode
P134 P145
P142
P136
Output
frequency (Hz)
Output
voltage (%)
Figure 9.5: Torque boost region for quadratic V/f control mode