User's Manual

20 LS420 Universal User Manual V2.91 2003-01-21.doc
2.6 Installation of radius calculation V1.0
Before proceeding with radius calibration:
•
Install the display unit (see section 2.1 of this manual).
•
Install the angle sensor (see section 2.3 of this manual). If a pendulum type angle
sensor is to be used it must be properly calibrated (see section 2.6.5 of this manual).
•
Install the length sensor (hydraulic cranes only) (see section 2.5 of this manual)
•
Enter the boom length on the boom length adjustment
screen of the display (lattice cranes only). This value
must be adjusted every time the length of the lattice
boom is changed.
•
Enter the jib length if the working hoist is rigged to a jib.
This value must be adjusted every time the length of
the lib is changed.
•
Enter the jib-offset angle if the working hoist is rigged to
a jib. This value must be adjusted every time the angle
of the jib is changed.
Note: for accurate radius display
when working with a luffing jib, an angle sensor must be installed on the luffing jib.
2.6.1 Radius calibration
The boom length (lattice cranes only), jib length and jib offset angle must be correctly entered in
the LS420 for accurate radius display. Furthermore, upon installation the LS420 must be cali-
brated for several crane specific angle and length parameters. Default values may have been
programmed at the factory before shipping. Upon installation these parameters must be con-
firmed and accurate radius display verified.
Step 1) Determine the following measurements to within a
tenth of a foot: slew offset, sheave head length and sheave ra-
dius. These measurements are described in sections 2.6.2 (lat-
tice cranes) and 2.6.3 (hydraulic cranes).
Step 2) Confirm the parameters entered in the advanced op-
tions of the LS420 display. Press the hoist button until the ad-
vanced options entry screen is displayed. Press the test button
to proceed to the advanced options. Verify that the radius pa-
rameters have been set correctly; the values may be adjusted
with the limit + and limit - buttons. Press the hoist button to
proceed from one parameter to the next.
Step 3) Test radius display. Compare the radius displayed with
the actual radius at different lengths of boom extension and dif-
ferent boom angles. If the radius displayed by the LS420 corresponds to the actual radius in all
cases, the radius function is correctly calibrated. Be sure that all radius parameters have been
carefully noted to facilitate re-calibration in the event of component or system upgrade, change,
or re-installation. If there is a difference between displayed radius and actual radius that remains
constant during changes in boom length and angle the slew offset can be adjusted to compen-
sate (see step 2 above). E.g. if the radius displayed is always 2.3 feet longer than the actual ra-
dius subtract 2.3 from slew offset. If the radius displayed is still different from the actual radius
proceed to section 2.6.4 of this manual (radius display trouble shooting).