Rice Lake JB4SS TuffSeal Signal Trim Junction Box - Manual (Page 8)

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4. Zero the indicator and place calibrated test weights over each load cell
in turn. The amount of test weights to be used will depend on the scale
confi guration; for specifi c recommendations, refer to Handbook 44 Field
Manual, published by the Institute for Weights and Measures. For a four-
cell platform, it's recommended using 25% of scale capacity.
5. Record the value displayed on the indicator after the test weight is placed
in turn on each corner (directly over the load cell) without allowing the
weight to overhang the sides. Allow the scale to return to zero each time
to check for friction or other mechanical problems. Select the load cell
which has the lowest value as your reference point. This cell will not be
trimmed.
6. Replace the same test load over each cell in turn. Using the correspond-
ing potentiometer, trim each cell down to equal the reference load cell.
As corner corrections are somewhat interactive, check all cells again for
repeatability. If necessary, repeat steps 4 and 5.
7. Pull excess cable out of the enclosure.
8. Using a wrench, tighten nut until the rubber touches the cable com-
pletely.
9. Then tighten the nut an additional 1/2 turn (180º). To be watertight, each
cord grip must be tightened so the rubber sleeve begins to protrude from
the hub.
10. Unused hubs must be properly plugged to prevent moisture entry. See
the Elec tron ic Replacement Parts and Components catalog to order extra
hole plugs.
11. Remove the desiccant from the plastic bag, and insert the des ic cant bag
into the junction box before closing. Inspect the desiccant during normal
service and change desiccant as needed.
12. Replace the cover and tighten the cover screws in an alternating pattern to
15 in/lb to be certain the gasket is compressed equally in all locations.