Rice Lake TSA Truck Scale Assembly - Manual (Page 10)

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4. Junction Box Connections, Adjustments & Calibration
1. Refer to the Junction Box manual for trimming details.
2. Refer to the indicator manual or the “Technical Information” section in the Rice
Lake Weighing Systems’ Load Cell Product Selection Guide for system
calibration details.
5. Troubleshooting
If the system powers up and gives some type of stable digital readout that varies
with the load on the system, any system problems are probably caused by factors
other than the load cells. The load cells are often blamed for a malfunctioning
system, but the majority of the time, the problem lies elsewhere. Look for
mechanical causes for your problem first.
If the system can be calibrated but doesn’t return to zero, loses calibration, or
demonstrates non-linearity or non-repeatability, see the following chart for pos-
sible causes and do the following checks.
1. Check load cell mount for debris restricting load cell movement or debris
between scale and structure.
2. Check that tank/vessel and mounts are plumb, level, and square at the
critical areas.
3. Check all piping and conduit for connections which restrict vessel
movement.
4. If check rods are used, loosen all connections to finger tight only for
testing.
5. Check load cell cables for physical or water damage.
6. Check all electrical connections, especially in the junction box.
Possible Cause
No return to zero
Mechanical binding or debris in seals or under load cells; may have lost system
calibration
Non-linearity Thermal expansion or deflection under load causing binding or side load
Non-repeatability
Loose load cell mount; drifting caused by moisture, load cell overload or shock
damage; mechanical binding
Lost calibration Out of level or plumb; moisture problem; mechanical binding
Drifting readout Moisture in junction box, cables, or load cell; mechanical binding
Symptom