Rice Lake BenchMark CW-80 Base - Manual (Page 8)

4 Benchmark HD Series
4.0 Load Cell Replacement
Use the following steps when replacing a load cell in the CW-80B.
1. Unplug AC power from indicator and disconnect load cell cable from indicator’s terminal connection strip.
2. Lift off scale top cover. Locate two upper load cell screws. Use 7/16” wrench to unscrew and remove those
two load cell screws. Do not remove four spring-loaded screws that attach load plate to spider assembly.
Lift off load plate/spider assembly as a unit. Remove spacer between load plate and load cell and set it
aside.
3.Turn scale over and back off Overload
P r o t e c t i o n S c r e w o n e c o m p l e t e t u r n .
Completely unscrew and remove the Lift up
Protection Screw.
Top Sub -Assembly
Load Plate/Spider
Load Cell Screw
Top Cover
Overload
Protection
Screw
Lift up
Protection
Screw
Load Cell Screw
4.Use 7/16” wrench to unscrew and remove two
lower load cell screws. The load cell and cable
can now be removed from scale. Do not lose
shim beneath load cell.
5.Thread cable of replacement load cell through
rubber grommet. Position load cell on shim and
screw in two lower load cell screws. Torque to
80 in lbs.
6. Replace Lift up Protection Screw by screwing it in until it lightly bottoms, then back it off 
1/4 turn.
7. Turn scale right side up. Position spacer on load cell, then place load plate/spider unit into position. Screw
in two upper load cell screws. Torque to 80 in/lbs.
8. Use an accurate caliper to check compressed spring length of the four overload springs as shown in Figure
3-2. If necessary, adjust length to specifications in Table 3-1. Replace top cover and re-level scale.
9. Connect load cell cable to correct pins on indicator terminal strip.
10. Tighten cord grip where cable enters indicator head. Reassemble indicator enclosure if required.
11. Recalibrate scale according to calibration instructions for the attached indicator.
12. Adjust Overload Protection Screw on bottom of scale by loading scale to 125% capacity. Place this weight
on top cover, centered on platform. With appropriate size hex wrench, screw in Overload Protection Screw
until it touches load cell, then back it off 1/6 turn. Recheck calibration.
Figure 4-1.
H –.02
CW-80B Load Cell Mounting
Figure 4-2. Overload Spring Height Adjustment