The Voltage drop is the part of the voltage that is lost along a cable. The longer the cable, the smaller the cross-section and the higher the current, the greater it is.
Why does this matter at 24 V?
At 24 V, losing just a few volts is a large share. If too little voltage reaches the actuator, it runs slower, lacks force or stops. A voltage drop of at most about 5 %, i.e. around 1.2 V, is usual.
Formula
Voltage drop ≈ 2 × length × current ÷ (56 × cross-section). 56 is the conductivity of copper in m/(Ω·mm²).
Example: 20 m of cable, 2 A and 1.5 mm² result in a voltage drop of around 0.95 V.
Learn more: Cable cross-section with table
Related terms: Cable cross-section
