The Difference Between Lifting and Load Capacity
Load capacity is the load a jack can hold on it while stationary; lifting capacity is the ability to move that load. The latter is limited by motor torque, gearbox ratio and supply voltage, and is usually lower. Do not interpret a catalogue value without knowing in which sense it is given.
Under a static load the mechanism only has to hold; friction helps and the motor does no work. When you want to move the load, however, the motor must produce the torque to overcome friction and raise the load. That torque depends directly on current, and current on supply voltage and cable cross-section.
- When the battery voltage drops the load capacity does not change, but the lifting ability decreases markedly. The jack slows down or does not rise at all.
- Temperature, grease consistency and corrosion increase friction and so reduce the lifting ability.
- For this reason the current protection usually trips at the lifting limit; the load limit is much higher up.
The quantity documented for the KTS200 is the load capacity (2000 kg/jack, 8000 kg total); no dynamic lifting value is stated in addition. The system should therefore be regarded not as a jack that lifts the vehicle into the air, but as a mechanism that carries part of the weight and corrects the angle.
Context in which this term is used: How to choose levelling jack capacity?