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Calibration
REGULATION (IR COMP)
The IR COMP trimpot setting determines the degree to which
motor speed is held constant as the motor load changes. It is
factory set for optimum motor regulation.
To calibrate IR COMP (exact calibration):
1. Turn the IR COMP trimpot full CCW.
2. Set the speed adjust potentiometer until the motor runs at
midspeed without load (for example, 900 RPM for an 1800
RPM motor) A hand held tachometer may be used to
measure motor speed.
3. Load the motor armature to its full load armature current
rating. The motor should slow down.
4. While keeping the load on the motor, rotate the IR COMP
trimpot until the motor runs at the speed measured in step 2.
Approximate calibration:
If the motor does not maintain set speed as the load changes,
gradually rotate the IR COMP trimpot CW. If the motor
oscillates (overcompensation), the IR COMP trimpot may be
set too high (CW). Turn the IR COMP trimpot CCW to
stabilize the motor speed. See Figure 10 (page 27) for typical
IR COMP and TORQUE trimpot settings.
250-0089r3_readers_spreads.qxd 7/3/01 10:48 AM Page 25
