KB Electronics KBWM-240 - Manual (Page 12)

Note: If only an AC ammeter is available, it can be installed in series with AC input
line. Follow above instructions; however, set AC amperage at 0.75 motor rating.
F. IR Compensation Adjustment – IR compensation is provided to 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 adjusted
to approximately 3% regulation. If superior performance is needed (less than 1% speed
change of base speed from 0 - full load), then the IR Comp. should be adjusted as fol-
lows:
Note: Excessive IR Comp. will cause control to become unstable, which causes motor
cogging.
1. Set IR Comp. trimpot at approximately 25% of CW rotation. Run motor unloaded at
approximately 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 pro-
cedure for more exact regulation.
The control is now compensated to provide minimal speed change under large varia-
tions of applied load.
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