Load cells are transducers that convert mechanical force into electrical signals. They are commonly used in weighing, force measurement, and material testing applications. Load cells come in different shapes and designs, but the most popular type is the strain gauge load cell.
In this article, we will discuss the wiring diagram for 4 load cells. We will cover the basic principles, the wiring connections, and some frequently asked questions about load cells. Let’s get started!
What is a Load Cell?
A load cell is a device that measures force or weight. It consists of a metal body with a strain gauge attached to it. When a force is applied to the load cell, the metal body deforms, causing the strain gauge to stretch or compress. This change in resistance is converted into an electrical signal that is proportional to the force applied.
Types of Load Cells
There are four primary types of load cells:
- Compression load cells
- Tension load cells
- Shear load cells
- Bending beam load cells
In this article, we will be focusing on the bending beam load cell.
Wiring Diagram for 4 Load Cells
The wiring diagram for 4 load cells is shown below:
| Load Cell | Color Code | Signal (+) | Signal (-) | Excitation (+) | Excitation (-) |
|---|---|---|---|---|---|
| Load Cell 1 | White | A | B | EX+ | EX- |
| Load Cell 2 | Green | C | D | EX+ | EX- |
| Load Cell 3 | Red | E | F | EX+ | EX- |
| Load Cell 4 | Black | G | H | EX+ | EX- |
Each load cell has two signal wires and two excitation wires. The signal wires (A, B, C, D, E, F, G, H) transmit the electrical signal generated by the strain gauge. The excitation wires (EX+, EX-) provide a constant voltage to the strain gauge to maintain its accuracy and stability.
In a 4 load cell system, the signal wires of all load cells are connected in parallel, while the excitation wires are connected in series. The wiring diagram shows the color code for the load cell wires, but it may vary depending on the manufacturer.
FAQ about Load Cells
1. How do load cells work?
Load cells work on the principle of strain gauge technology. When a force is applied to the load cell, the metal body deforms, causing the strain gauge to stretch or compress. This change in resistance is converted into an electrical signal that is proportional to the force applied.
2. How accurate are load cells?
Load cells are highly accurate, with most models having a precision of 0.1% or better. However, the accuracy may be affected by environmental factors such as temperature, humidity, and electromagnetic interference.
3. How do I calibrate a load cell?
Load cells need to be calibrated periodically to ensure accurate measurements. Calibration involves applying known weights or forces to the load cell and comparing the readings to the actual values. The calibration procedure may vary depending on the type and model of the load cell.
4. How do I troubleshoot load cell problems?
If you encounter problems with your load cell, check the wiring connections, the supply voltage, and the load cell output. Make sure that the load cell is properly installed and protected from external forces that may affect its accuracy.
5. Can load cells be used in hazardous environments?
Load cells can be used in hazardous environments but require special construction and protection measures. They may need to be rated for explosion-proof, intrinsically safe, or non-incendive use depending on the type of hazard present.
Conclusion
In this article, we have discussed the wiring diagram for 4 load cells, the basic principles of load cell technology, and some frequently asked questions about load cells. We hope that this information will be helpful for those who are planning to use load cells for weighing, force measurement, or material testing applications.
