Rice Lake TradeRoute HL Series - Installation and Service Manual (Legal-for-Trade) - Manual (Page 32)

28 Trade Route Installation Manual
5. Repeat step four for the other load cells with the same procedure (remembering to press the zero key to
obtain a good center of zero). All the readings should be within approximately 1 percent of each other. If
the readings are significantly farther apart, you may not be able to balance your system. Contact Rice Lake
Weighing Systems for technical assistance.
6. Pick the lowest reading and adjust the other load cells down to this value with the trimmers inside the
j-box.
7. With no weight on the scale, zero the indicator. Then turn all four potentiometers (shown in Figure 3-5) to
increase the reading until a clicking sound is heard from each potentiometer. This ensures the maximum
signal from each load cell.
JP4
JP2
PT4 PT3 JP3
PT1
EXP
PT2
JP1
1
CELL4
1
CELL1
1
CELL3
1
CELL2
IND
-EX
-SI
SHD
+SI
+EX
M
R
N
I
-SI
S2 C
I
A
G
+EX
+SI
-SI
SHD
-EX
I
S
G
A
L
T
+SI
M
S
I
N
L
T
R
+EX
-EX
-SI
SHD
+SI
+EX
+SI
-EX
-SI
SHD
-EX
SHD
+SE
-SE
+EX
Potentiometers
Jumper Locations
JP1 and JP2
Shaded
Jumper Locations
JP3 and JP4
Shaded
Potentiometers
Figure 3-5. Trim Potentiometers
With all potentiometers at full signal, place the test weight over one corner and record the indicated weight.
Repeat the process for each of the other three corners. The load cell with the lowest corner reading will be
used as a reference point and will not be trimmed.
8. Test the final balance by loading each load cell again and recording the 920i readings. The load cells must
read within one graduation of each other for an acceptable final balance. However, it is more desirable that
there be no difference in the readings (zero balance error).
9. The system can now be calibrated.
EXAMPLE: OB30L-F3 System
Balancing Weights
English = 5000 lb
Metric = 2000 kg
Graduations
English = 5 lb
Metric = 2 kg
Table 3-3. First Loading
English Units (lb)
Load Cell
Metric Units (kg)
920i Reading 920i Reading
Start Loaded Unloaded Start Loaded Unloaded
0 4995 0 1 0 1998 0
0 4990 0 2 0 1996 0
0 5005 0 3 0 2002 0