Manual 26727
VariStroke-I (VS-I) Electro-hydraulic Actuator
Woodward
72
Set Offset and Maximum Stop Position
If one of the calibration routines has already been run, or the user
wishes to adjust these values based on the factory calibration, the
“Adjust Minimum Offset and Maximum Position” button may be
pressed. This will skip the automatic calibration process.
Figure 5-7. Calibration Complete Screen
After either calibration routine is run, the service tool will return to the Calibration page where setting the
desired “Offset at Minimum Position” and “Maximum Stop Position” is now allowed. The Maximum Stop
Position minus the Offset at Minimum Position must not be less than 40% of the Factory Maximum stop
position shown on at the bottom of this page, or an Illegal Stroke Percent Error will appear.
The “Offset and Minimum Position: and “Maximum Stop Position” settings are presented in millimeters for
user convenience. If a specific stroke length is required, the user shall adjust these parameters while
verifying the actual actuator minimum and maximum positions. Some small variation between these
parameters and the actual stroke is allowed, and the final stroke will be linear between the actual
minimum and maximum positions.
After changing the “Offset at Minimum Position” and “Maximum Stop Position”, press the Apply button.
During this process, the “Position Request” on the right side of the page can be used to manually position
the actuator during this process. The “Manual Slew Rate” is also shown, but is for reference only. “Manual
Slew Rate” can be changed on the Config/Calibrate page, before entering the Calibration mode.
If calibration was performed with linkage attached, a small negative
number can be input into the “Offset at Minimum Position” field to
provide additional valve seating force.
It is the installer’s
responsibility to verify the structural capabilities of the linkage and/or
attachments.
Released