Valco Cincinnati VC350A, Manual

Page: 52 / 327

Section 7 — Initial Setup VC350A Flexoseal
®
System
Valco Cincinnati 7-9
IR Compensation Potentiometer
For automatic mode only. An IR compensation potentiometer (Figure 34) is provided to substantially improve load
regulation. If the load presented to the motor does not vary substantially, the IR comp may be set at a minimum
level (approximately one-quarter of the full setting).
If superior perforcmance is desired (less than 2% speed change of base speed from zero to full load), the IR comp
should be adjusted as follows:
1. Set the IR potentiometer at approximately 50% of travel.
2. Run the motor at approximately one-third speed and record the revolutions per minute.
3. Run the motor with a maximum load and adjust the IR potentiometer so that the motor speed under the
load equals the unloaded speed (see step 2).
4. Remove the load and recheck the unloaded revolutions per minute.
5. If the unloaded revolutions per minute have shifted, repeat step 2 for more exact regulation.
The control is now compensated to provide minimal speed change under large variations of applied load. If the IR
compensation is set too high, unstable motor operation will occur. This will be evident if the motor speed increases
and decreases in a cycle. To correct this problem, rotate the IR compensation potentiometer counterclockwise.
IR compensation potentiometer
Figure 7-7. IR Compensation Potentiometer