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W450769A 01/14
3.4.2 Displayed Load or Radius Errors
This section gives direction to fault diagnosis of load and radius errors. Load or radius errors can cause
early or late tripping of overload alarms. Accuracy of load, radius, length, and angle is determined by
the correct installation and maintenance of the system sensors. Accuracy of load is governed by the
radius accuracy, and the extension, angle, and pressure sensors. Accuracy of radius (unloaded) is
governed by the extension and angle sensors.
Ensure there are no system faults before continuing.
3.4.2.1 Check Boom Extension
1. Ensure the boom is fully retracted.
2. Ensure the Reeling Drum cable is correctly layered as a single layer across the Reeling Drum
surface. Any stacking of the cable will cause extension errors when the boom is fully retracted.
This will cause the System to exceed the 0.5 ft tolerance allowed by the computer for boom
mode selection. If the Reeling Drum cable is stacking on the reel, see
SECTION 3.8.1
CHECKING THE REELING DRUM CABLE LAYERING
.
3. Check the zero of the extension sensor with the boom fully retracted. Enter the Calibration
Mode and use the “SPAN” command. Select sensor No. 2 to view the extension value in feet.
The value of extension must be between -0.2 and +0.2, with the boom fully retracted. If the
extension value is incorrect, refer to
CHAPTER 2 - CALIBRATION
. Fully extend the boom and
ensure the displayed boom length value matches the maximum length of the boom. If the length
value is incorrect, refer to
SECTION 3.10.4 SPAN CALIBRATION
.
3.4.2.2 Check Main Boom Radius
1. Ensure the correct crane configuration is in use and fully retract the boom.
NOTE: The required accuracy of taped radius measurements is 0.1 feet. When taking radius
measurements use a good quality tape that does not stretch. Use a tape graduate in feet and tenths of
a foot. Always measure between the swing center of the crane and the hook line, using a single part of
line with the crane centered over front (rough terrain) or centered over rear (truck crane).
2. Raise the boom to about 45° and measure the radius. The measured radius must match the
displayed radius /- 0.2 ft. If it does not match, continue to the
CHECK BOOM ANGLE
procedure. If it does match, continue to
CHECK PRESSURE SENSORS
.
3. Raise the boom to a high angle (at least 70°) and measure the angle with the inclinometer.
Ensure the displayed angle matches the inclinometer reading within 0.2°. If the displayed angle
is incorrect, follow the angle span calibration procedure in
SECTION 3.10.4
SPAN
CALIBRATION
.
3.4.2.3 Check Boom Angle
1. Fully retract the boom.
NOTE: The required accuracy of measured angles is within 0.2°. When taking boom angle
measurements use a good quality inclinometer. Many inclinometers are only accurate at 0°. Ensure a
reliable position on the top of the boom is used to measure the angle and that the inclinometer will
provide an accurate reading at 0° and at 70°
.
2. Using an inclinometer set the boom to 0° and ensure the displayed boom angle value is 0.0°. If
the angle value is not 0.0°, follow
SECTION 3.8.5 CHECKING THE ANGLE SENSOR
PENDULUM.
