Fairbanks Aegis Drum Scales - Manual (Page 20)

Section 4: Service & Maintenance
04/10 20 51190 Rev. 2
4.2. SCALE PLATFORM TROUBLESHOOTING
Except for severe structural damages, most Platform Assembly problems can be
traced to the following causes.
• Material under or around the Platform.
• Broken Load Cell Feet.
• Faulty Load Cells.
• Incorrect, loose or damaged Load Cells.
4.2.1. Scale Platform Testing
1. Inspect the Interface Cable from the Platform to the Instrument for visible breaks
or cracks.
2. ZERO the Instrument Display.
3. Apply a test load of 25% of the Load Cell capacity to one corner.
─ The Instrument should display a weight reading within 0.1% of the applied
weight, or One Instrument Division, whichever is greater.
4. Repeat Step 3 for all the corners, placing the same Test Load on each corner.
4.2.2. Load Cell Testing
When corners do not match the correct tolerances, unsolder each Load Cell Cable,
then test each Load Cell for the settings on the following chart.
TEST READING REMARKS
Green to Black (Input) 1106 Ohms (+5 / -2 Ohms) Input Resistance
Red to White (Output) 1000 Ohms (+5 / -2 Ohms) Output / Bridge Resistance
Yellow (Shield) to Load Cell Case
More than 1,000 megohms Insulation Resistance Input and Output Leads to Shield
Input and Output Leads to Case
If any Load Cell fails, it should be replaced according to Subsection 4.4.