Chapter 10: Troubleshooting
Load Cell Replacement
(2/01)
10-5
7.
Remove the two load cell mounting screws and keep them for reinstalling the new
load cell. Use a 3/8" hex Allen socket wrench to remove the 1/2-13 UNC socket
head cap screws that mount 250-lb to 5,000-lb load cells. Use a 1-1/8" hex Allen
socket wrench to remove the 3/4-10 UNC socket head cap screws that mount
10,000-lb load cells. Then lift the load cell from the mounting surface.
8.
Carefully pull the defective load cell’s cable through the platform while feeding the
string in at the junction box opening. Once the string is at the load cell location,
detach it from the load cell cable.
9.
Remove the rocker pin with O-rings from the defective load cell. Reinstall it in the
new load cell.
10.
Attach the new load cell’s cable to the pulling string and carefully thread it through
the platform into the junction box opening. Coil any excess cable and store it within
the platform side channel.
11.
Secure the new load cell to the platform. Apply an anti-seize compound such as
Never-Seez to the threads of the mounting screws and tighten with a calibrated
torque wrench to 100 ft-lb (250-lb to 5,000-lb load cells) or 250 ft-lb (10,000-lb
load cells).
12.
Verify that the load cell overload stop gap is set properly:
Load Cell Capacity
Overload Stop Gap
250 lb
0.009" to 0.012"
500 lb
0.009" to 0.015"
1250 lb
0.012" to 0.018"
2500 lb
0.017" to 0.023"
Figure 10-1: Load Cell Installation
13.
Thread the load cell cable through the connector on the junction box. When enough
cable is inside the box, tighten the connector.
14.
Wire the new load cell cable to the proper terminal on the PCB according to the
wiring codes shown in Chapter 3.
15.
Reinstall the platform in the frame. Make sure that the rocker pins are properly
seated and aligned with the receivers in the frame.
16.
Reconnect the instrument cable and power-up the indicator. Perform a shift adjust
and recalibrate the scale.
Note: Make sure load cell and platform
mounting surfaces are free of grease
and other foreign materials.
Note: 5,000-lb and 10,000-lb load
cells do not have an overload stop.
Bumper Gap 0.06" (0.16" for 10K load cells)
Platform
Frame
Lower Receiver
O-Ring
Rocker Pin
Load Cell
Load Cell Mounting Screws
Overload
Stop Gap
