Features to Consider:

• German Made WAGO color coded terminal blocks for easy identification of excitation, signal and sense for quick (reading glasses free) installation
• The expansion terminal allows connection of multiple junction boxes to connect up to 24 loadcells
• The signal disconnect jumpers allow isolation of individual loadcells which allows 1, 2 or 3 loadcells to be used per summing board
• The gas discharge tubes and grounding lug provide transient surge protection for your loadcell system blocking harmful voltage spikes that can be transmitted through the homerun cable
• Easy to read durable laser markings on the enclosure provide recommended wire stripping lengths & quick QR Barcodes to installation documents
• Loadcell Numbering, Excitation, Signal and Sense markings are large and easy to read on the printed circuit board
• large and high quality rechargeable desiccant packs included standard to guard against moisture buildup in humid climates
• Circuit boards are solidly mounted to the enclosure with brass inserts & stainless hardware so you don't have to worry about shoddy adhesives coming loose from heat and vibration

Consider the following factors when installation of a DrySummix junction box

• Ease of servicability
• • Can you easily reach the front cover and have enough room to open the lid with the proper tool?
  • Is the box oriented to easily read markings and insert wires into the terminals
  • Can you tighten the cord grips onto the loadcell wires easily and reliably
• Environmental
• • Be in the way of other production or cleaning processes for the customer
  • Solid structure suitable for long term durability
  • Protected from splashing of customers product, cleaning chemicals & rain
  • Include "drip loops" so that any moisture accumulating along cables drip off before going into the cord grips
  • Are there any heat or vibration factors that should be mitigated
• Electrical
• • Proximity to grounding rod or single point ground for transient protection
  • Allow easily running of load sensor and instrument homerun cables along existing conduit or scale/tank/hopper structures
  • Avoid running any of the low voltage scale signal lines near any high voltage pump, motor or power lines to reduce the potential for electrical noise to be present in the weight signal

The junction boxes can be mounted specific to their enclosure types listed below

(Need a picture of the scale deck and the loadcell numbers outlined with the board corresponding to cell numbers)

Determine the layout of the loadcells that you would like to connect, typically you would lay the board out flat in front of you and each loadcell is wired to the corner of the board that it is closest to.  This way when trimming later it is intuitive which cell number you need to adjust based on where the weight is placed on the scale deck.

Determine the wiring pattern to be used (diagram needed here)

2. Route the load cell cables through the cord grips, do not tighten the grips. 

3. Strip the wire insulation back 1/4 inch to expose the wire. 

4. Push in and hold the quick-connect lever with a small screwdriver.

 5. Insert the appropriate wire into the exposed wire opening. 

6. Release the screwdriver to allow the spring-loaded gate to close and lock the wire in place.

Need to have a guide on how to wire the single point ground to building or ground rod

We will need to show how to setup multiple boards daisy chained and what to watch out for

This will also need to be mostly Jeremy to help with this as I am not sure what to include???

Follow the steps below to properly trim the DrySummix SB4TP loadcell summing cards for accurate load cell balancing and scale performance.

1. Determine the Number of Load Cells

Identify the total number of active load cells being used in the scale system and which orientation the box is mounted so that the position the cells are connected makes sense if you were to lay the board flat in front of you

(Picture of floor scale here)  with picture of the summing board pointing from loadcell to board laying flat

2. Verify Wiring and Set the Jumpers

Verify that the jumpers are ON (connected) for all active load cells to enable the trimming functionality for that loadcell.  You MUST Remove jumpers (OFF or not connected) for any unused load cell positions.  You can easily set the jumper onto a single pin so that it is stored with the board should you need it later or you can remove it completely and keep as a spare in your parts kit.

3. ALREADY SET Initial Potentiometer Positions 

It is NOT recommended to adjust your potentiometers from their current positions.  

Each potentiometer is set from our factory at the exact "Mid-Range" (52K Ohms) for each loadcell channel.  This methodology is a tradeoff for overall trimming range (difference you are able to adjust between the two furthest cells) and the speed/ease of minor adjustments to the device in the future.

Since the potentiometers are set to midrange, any loadcell can be easily adjusted up OR down to trim minor differences.  This prevents having to completely reset all loadcells and trim multiple cells for a small error on a cell that has run out of adjustment range because the potentiometers have already been maxed out.

4. Prepare the Indicator

With the scale unloaded, zero the indicator according to the indicator manufacturer’s instructions.  It may be best to put a preliminary calibration on the scale so that the weight values displayed are close to what you are expecting once finished.  This ensures that you are not chasing a corner error that won't be visible when the final calibration is applied. 

5. Apply Test Weights

Place calibrated test weights directly over each load cell, one corner at a time.  Being precise in the where the weight is applied to each corner will help with trimming corners quickly. 

The amount of weight used will depend on the scale capacity and configuration.  Recommended Practice:  For a four-load-cell platform, NIST Handbook 44 recommends using approximately 25% of the scale’s total capacity as test weight.  Typical floor scale trimming is done with 500lb or 1000lb block weights on each corner at minimum.

6. Record Displayed Values

Record the indicator reading for each corner after the test weight has stabilized. Ensure the weight is centered directly above the load cell and does not overhang the platform.

(picture of 500lb weight on floor scale corner)

7. Verify Return to Zero

After removing the test weight from each corner, allow the scale to return to zero. This helps identify friction, binding, or other mechanical issues.  These must all be resolved prior to attempting any electrical adjustments like we are doing in this procedure.

8. Establish the Reference Load Cell/s

Identify the load cells that match each other.  Typically two or three cells will be the same and the other cells will be slightly different from your nominal value.  

If you had already put a calibration into the instrument with certified test weight we will plan to adjust the cells that don't match nominal test weight value

9. Trim Remaining Load Cell/s

Place the same calibrated test weight over the loadcells that did not match in the corner in the same exact place your originally set them

10. Adjust the Corresponding Potentiometer

Using the matching potentiometer, adjust the output of that load cell until the indicator reading matches the reference load cell value/s or matches the nominal test weight value.

The trim direction is shown in the center of the circuit board with the rotating arrows:

To the right (clockwise) decreases the weight shown on the scale instrument

To the left (counter clockwise) increases the weight shown on the scale instrument

If your weights are behaving opposite then you have the signal wires from the loadcell connected backwards

11. Repeat for All Remaining Load Cells

Continue the trimming process for each remaining load cell until all corners display equal readings.

12. Verify Repeatability

Recheck all load cells for consistency and repeatability. If necessary, repeat the trimming procedure until all corners are balanced accurately.  It is very important that once you feel you are completely done with adjusting the potentiometers that you go back and set the test weight on all of the other cells to ensure none were affecting by your most recent adjustment.

If all of the cells are displaying the nominal value of the test weight then you can proceed.  If they are all the same but a few divisions from nominal then you must refer to the calibration documentation for the instrument it is connected to and perform a zero and span calibration to make the scale display the accurate nominal test weight value.

13. Install Desiccant Drying Pack

Place the supplied desiccant drying pack inside the junction box to help protect against moisture and condensation.  It is recommended to tuck it down into the box away from the circuit board or wires.  Should the pack become saturated with water we want it as far away from the board as possible for the most reliable experience for the end user.

14. Secure the Junction Box Cover

Replace the cover and tighten the screws evenly in an alternating cross pattern to ensure proper gasket compression and environmental sealing.

(Image of the top box with screws going in numbered in a cross pattern)

Important Maintenance Note

Inspect the desiccant during routine service intervals and replace it as needed to maintain moisture protection and long-term reliability especially in humid climates

Next time we do some board assembly we need some images of removing the board and installing a new one in the ABS enclosure

Best easiest way to check any of the terminal blocks with standard multimeter prongs

fastest way to check the signal wires for the millivolt signal from the loadcells

Notes on the standard values you should find at each location

we will need how to check if the GDTs have been blown

how to check if the pots are balanced

how to check for good grounding to single point location