Rice Lake Combination System - Precision Loads On-Board Weighing Systems - Manual (Page 31)

Applications 27
To prevent distortion or twisting of the subframe, stiffening may be required. The installer must assess any
potential for a weak frame area, and must consider the type of frame involved, the relative position of existing
crossmembers, and the best method of stiffening to be used, whether by glove section, web stiffeners, etc. See
Section 4.2.3 on page 22.
Rice Lake Weighing Systems recommends that load cells mounting brackets be made of no less than 0.50 inch (13
mm) thick heavy steel construction. Angle iron mounting brackets must always be gusseted in the areas between
the top load cell mounting bolts. Refer to Appendix drawings.
Prior to mounting of the load cell brackets, inspect all body subframe rails to ensure they are clean and straight
(providing a flat mounting surface for the mounting bracket is sometimes required). Look for any evidence of
cracking or corrosion, pitting, burrs or other characteristics which can adversely affect the strength of the
installation, or the correct fit of the load cell angles.
Access to the load cell bolts for the final installation and post-installation bolt torque maintenance is important.
Always ensure that adequate space and clearance is provided beneath the trailer subframe for access to all load cell
mounting bolts.
Correct alignment of the installation is critical to proper system performance. Always ensure that all frame
members are kept straight and do not bend, warp or crack when cutting or welding takes place. Avoid 90 degree
angle welds.
4.3.3 Installation Procedure
1. Assemble the trailer subframe mounting brackets to the top of the load cell using the 1 inch diameter top
mounting bolts supplied. Both Model PL9000-22 and PL9000-26 load cells use these (three) top bolts. The
installer must ensure that the top mounting bolts used are of the correct length so that sufficient thread
engagement into the cell is ensured and also that longer bolts do not bottom-out in the tapped holes of the
load cell. The PL9000-22 load cell uses three 1"-14UNF x 1.50"L bolts and the PL9000-26 load cell uses
three 1"-14UNF x 2"L bolts. Bolts which are not secure, and either too long or too short, could result in a
hazardous operating condition. Check carefully for correct bolt length. See “Bolt Torque Values” on
page 58
2. Tighten all three top bolts. Assemble the load cells by bolting up the single piece bearing plates into
position. Tighten the bearing plate bolts.
3. Cable output from the load cell should always face inward towards the longitudinal center of the body. If
this is not possible to ensure access to the cable connector, protect outward facing cables from potential
damage.
4. To install the load cell mounting brackets (angles) to the trailer subframe, position temporary spacers
between the kingpin skid plate and the trailer frame rails to allow for a clearance after installation of 1/2 to
3/4 inches (13 to 19 mm). In lifting and positioning the kingpin plate assembly into its final assembly
position, verify its correct alignment with the trailer subframe.
5. Tack weld (or bolt) both load cell mounting angles to the trailer subframe rails. Verify correct alignment of
the kingpin plate and the trailer subframe rails.
6. Tack weld the load cell bearing plates to the kingpin skid plate. Verify alignment of the skid plate and body.
Ensure that the load cell bearing plates rest flatly on the skid plate, Shim any gaps that are found to be
greater than 1/32 inch (1 mm).
7. Disassemble the load cell and remove the kingpin plate. Review “Welding Specifications” on page 59
before proceeding. Perform final welding of the two load cell mounting angles to the trailer subframe rails.
8. Perform final welding of the load cell bearing plates per instructions for welding single-piece bearing
plates. Observe all cautions.