load cell wiring diagram

Most load cells use a standard coloring: red for Excitation+, black for Excitation-, green for Signal+, and white for Signal-. In 6-wire versions, blue and yellow often stand for Sense+ and Sense-. But never rely on color alone—always check the manufacturer’s data sheet because some brands deviate from this convention.

You can connect a 4-wire load cell by bridging the Sense+ to Excitation+ and Sense- to Excitation- at the indicator terminal. This locally senses the excitation voltage, but you lose the ability to compensate for cable resistance. For long cable runs, it’s better to use a load cell with sense wires to maintain accuracy.

Yes, unstable readings often point to poor connections or noise. Check that all wires are securely screwed down, the shield is connected only at the instrument end, and the cable isn’t running alongside power lines. Moisture in the cable or junction box can also cause drift, so look for corrosion or damaged insulation.

You can extend it, but adding length increases resistance and makes the signal more susceptible to electrical noise. If you must extend, use a 6-wire system for sense compensation, use shielded twisted-pair cable, and solder or use proper crimp connections—never just twist wires together. Recalibrate the system after any extension.

Start by measuring resistance between the excitation leads—it should match the datasheet (typically 350 or 1000 ohms). The signal leads should show similar resistance. Check for shorts between shield and any wire. With no load, the signal voltage (mV) should be near zero. If values are way off, you might have swapped excitation and signal wires.