Rockwell Automation 1302 575v AC Drive - Canada Only - Manual (Page 65)

8–7 Programming
Publication 1302-5.0 — January, 1998
FĆ06 Manual Torque Boost
This parameter sets the
percentage of output voltage
boost at zero frequency.
Parameter Range:
Default Setting:
Step Size:
0 to 10%
2%
1%
Torque boost offsets the voltage drop of the AC motor at low speeds. For high friction loads or high
inertia loads, a high starting torque level may be needed. Manual torque boost is only effective at speeds
lower than oneĆhalf of the motor's base frequency. See Figure 8.1.
When adjusting this parameter, start with the default setting of 2% and gradually increase the value until
motor operation is satisfactory. If torque boost is set too high relative to the load and acceleration rate,
an overcurrent fault may occur (OC will be displayed).
Figure 8.1 - Manual Torque Boost Adjustment Range
Base Speed Base Speed
2
FREQUENCY (Hz)
Manual Torque Boost
0
10
50
100
OUTPUT VOL
TAGE (%)
FĆ07 V/Hz (Base Speed)
This parameter specifies the
base speed at maximum output
voltage and is used to establish
the volts/hertz (V/Hz) curve.
Parameter Range:
Default Setting:
Step Size:
30 to 240 Hz
60 Hz
1.0 Hz
The V/Hz curve allows the Drive to maintain a constant V/Hz ratio, providing constant torque at any
frequency. See Figure 8.2.
Figure 8.2 - Volts/Hertz Curve
FREQUENCY (Hz)
0 240
100
Base
Frequency
Output V
oltage (%)