rinstrum 0075 Junction Boxes Installation Guide

: June 13, 2024
: rinstrum

Table of Contents

rinstrum 0075 Junction Boxes
Product Information

rinstrum 0075 Junction Boxes

Product Information

The 0075/0076/0078 Junction Boxes are used for the installation and connection of load cells in a scale system. They feature a 5-way terminal strip for each load cell, allowing the connection of 4-wire load cells with shield connection. The terminal strips are screw-operated cage clamp design. The boxes are available in three models: 0075, 0076, and 0078. They have different shell materials and dimensions. The 0075 model has a polymer shell, while the 0076 and 0078 models have stainless-steel shells. The dimensions of the boxes are as follows: 0075 – 180mm x 65mm x 43mm, 0076 – 175mm x 91mm x 42mm, and 0078 – 192mm x 124mm x 43mm. They also have different levels of environmental protection (IP rating): 0075 – IP65, 0076 – IP6X, and 0078 – IP68. The boxes come with cable glands for connection and trimming of signal output is done using 30-turn trim potentiometers.

Product Usage Instructions

Before installation, ensure that any unused cable glands are closed with suitable plugs.
When connecting the cable shields, make sure not to create ground loops to avoid disturbance.
To mount the Junction Box, use the provided 2 or 4 mounting holes. Ensure that the enclosure is connected to the scale framework with the lowest risk of getting wet.
After completing all wiring and powering up the scale instrument, check for repeatability and correct any issues.
To trim the output from multiple load cells, follow the corner adjusting method described below:
Before starting trimming, set each potentiometer (W1-W4) to the halfway point by turning it up or down 15 turns from the clicking point.
Connect each load cell cable to the matched terminal of the Junction Box through PG9 connectors.
Connect the indicator with a cable through PG9 to the Junction Box and set the indicator to Zero.
Place test weights over each load cell (each corner) and on the center point in turn. For a four-load-cell scale, use a weight of 25% of the full-scale capacity.
Record the value displayed on the indicator after placing the test weight on each corner and center.
Select the lowest corner value compared to the center value. Adjust the potentiometer of that corner clockwise to increase its value. Alternatively, select the greatest value compared to the center value and adjust the potentiometer of that corner counterclockwise to decrease its value.
Repeat steps 5 and 6, replacing the same test weight over each cell and center in turn, until all values are within the required range.

0075/0076/0078 Junction Boxes

Installation

Cable glands that are not used need to be closed with suitable plugs. It has a 5-way terminal strip for each load cell, enabling connection of 4 wire load cells with shield connection. Terminal strips are screw-operated cage clamp design. To overcome disturbance, make sure not to create ground loops whilst connecting the cable shields. Trimming of signal output is accomplished using 30-turn trim potentiometers. Remove the cover and connect the load cell cables to the circuit board and the circuit board output to the associated indicator. Each load cell terminal strip has the same sequence for connecting the respective wires as the output terminal strip. Be sure that all terminal strip connections are tight and that the cables are not damaged. The load cells used should be of the same model, and capacity and have the same rated output (mV/V). Tinning the leads is not recommended for vibrant applications. Make sure all screws and gaskets are tight when putting the cover back on. Make sure to properly tighten the cable glands to keep the sealing intact.

Mounting

The Junction Box can be mounted through the 2 or 4 mounting holes. When installing the junction box, be sure that the enclosure is connected to the scale framework with the lowest risk to get wet.

Specification

	0075	0076	0078
Shell Material	Polymer	Stainless-Steel	Stainless-Steel
Connections	5 x PG7 Polymer Glands	5 x PG7 Polymer Glands	5 x PG7

Mounting Holes

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Note : 0075-M12 is the M12 cable extension variant for 0075. This model contains 4 Female 5 pin M12 headers (loadcells) and 1 Male 5 pin M12 header (indicator).

Connection Diagram

Trimming

After all wiring is completed and the scale instrument is powered up, check the scale for repeatability and correct any problems. The potentiometers nearest to the terminal strip (W1-W4) adjust the respective load cell connected to it.
Trimming is a process of equalizing the output from multiple individual load cells by adjusting each matched potentiometer. The corner adjusting method described below can be used to achieve the best possible performance.

Each potentiometer should be at the halfway point before starting trimming, please turn it up or down 15 turns (Max Turns/2) from the clicking point.
Connect each load cell cable to the matched terminal of the Junction box through PG9 as the figure is shown above, and connect the indicator with a cable through PG9 to the Junction box as well.
Set the indicator to Zero, then place test weights over each load cell (each corner) and on the center point in turn. For a four-load-cell scale, it’s recommended to use a weight of 25% of full-scale capacity.
Record the value displayed on the indicator after the test weight is placed in turn on each corner and center. Select the lowest corner value compared with center value, adjust the potentiometer of the corner by clockwise turn to increase the value of this corner, or select the greatest value compared with center value, then trim the potentiometer of the corner by counterclockwise turn to decrease the value of this corner.
Replace the same test weight over each cell and center in turn. Adjust the potentiometers to trim each load cell up or down to equal the value of each corner to the center. Check all cells again for repeatability, repeat steps 2 and 3 if necessary, until all the value is within the required range.