27
c. Apply power; Rotate CL trimpot CW until desired CL setting is reached (factory
setting is 1.5 times rated motor current). Be sure control is in Forward direction for
FCL trimpot adjustment and likewise with RCL.
WARNING! DO NOT LEAVE MOTOR SHAFT LOCKED FOR MORE THAN 2 - 3
SECONDS, TO PREVENT MOTOR DAMAGE.
CAUTION: Adjusting the CL above 150% of motor rating can cause overheating and
demagnetization of some PM motors. Consult motor manufacturer.
10.4 IR Compensation (IR Comp)
- The IR Comp is
used to stabilize motor speed under varying
loads. The IR Trimpot is factory set to 5 Volts
DC, with 115 Volt AC line input, and 10 Volts
DC, with 208/230 Volt AC line input. See
Figure 23.
If control is in Tach Feedback mode, the IR
Comp should be set to minimum -CCW.
Note:
Too much IR Comp will cause unstable
(oscillatory) operation.
Readjust the IR Comp trimpot as follows:
a. Run motor at approximately 30-50% of rated speed under no load and measure
actual
speed.
b. Load motor to rated current. Rotate IR Comp trimpot so that loaded speed is the
same as the unloaded speed measured in the previous step.
Control is now compensated so that minimal speed change will occur over a wide range
of motor load.
FIGURE 22A – FORWARD
CURRENT LIMIT TRIMPOT
POSITION
FIGURE 22B – REVERSE
CURRENT LIMIT TRIMPOT
POSITION
FIGURE 23 – IR
COMPENSATION TRIMPOT
POSITION
