Rapid-Air STRAIGHTENER: SBX, SCX & SD SERIES - Manual (Page 26)

To set the CL to factory specification adjust as follows:
1. Set speed control knob at approximately 30-50% CW rotation.
Set CL trimpot to full CCW position.
2. Connect a DC ammeter in series with the armature lead.
3. Lock shaft of motor (be sure CL pot is in full CCW position).
Apply power and rotate CL pot CW slowly until DC ammeter reads 1.5 times motor
rating (do no exceed 2 times motor rating, Max. CW position.)
F. IR Compensation Adjustment. IR compensation is provided to substantially improve load
regulation. If the load presented to the motor does not vary substantially, the IR adjustment
may be set at a minimum level (approximately 1/4 of full setting). The control is factory ad-
justed to approximately 3% regulation. If superior performance is desired (less than 1% speed
change of base speed from 0 to full load), then the IR comp. should be adjusted as follows.
1. Set IR comp. Trimpot at approximately 25% of CW rotation. Run motor unloaded at ap-
proximately 1/3 speed and record RPM.
2. Run motor with maximum load and adjust IR comp. trimpot so that the motor speed under
load equals the unloaded speed per step 1.
3. Remove load and recheck unloaded RPM. If unloaded RPM has shifted, repeat procedure
for more exact regulation.
The RAMM is now compensated to provide minimal speed change under large variations of
applied load.
NOTE: If only an AC ammeter is available, it can be installed in series with the AC line.
Follow above instructions; however, set AC amperage at .75 times motor rating.
NOTES: 1. Excessive IR comp. Will cause control to become unstable, which causes
motor cogging.
2. For tach feedback applications the IR comp can be set to minimum rotation
(full CCW).