28
MMRG Series
IR Compensation (IR COMP)
The IR COMP setting determines the degree to which motor speed is held
constant as the motor load changes.
Use the following procedure to recalibrate the IR COMP setting:
1. Set the IR COMP trim pot to minimum (full CCW).
2. Increase the speed adjust potentiometer or input voltage signal
until the motor runs at midspeed without load (for example,
900 RPM for an 1800 RPM motor). A handheld 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 trim
pot until the motor runs at the speed measured in step 2. If
the motor oscillates (overcompensation), the IR COMP trim pot
may be set too high (CW). Turn the IR COMP trim pot CCW to
stabilize the motor.
5. Unload the motor.
See Figure 14 on page 29 for recommended IR COMP settings.
