Answer from Ningbo Changshi: Selecting the correct machine size is a critical decision that impacts safety, efficiency, and project cost. The primary factor is not the size of the cable itself, but the total pulling force required. To make the right choice, consider the following:

• Cable Weight and Length: The longer and heavier the cable, the more force will be required. This is the base load of the pull.

• Friction: The biggest variable is friction from the conduit or duct. Rough surfaces, small conduit diameters, and contaminants will dramatically increase the required force.

• Bends and Elevation Changes: Every bend, incline, or decline in the cable route adds a significant multiplier to the pulling tension. A single 90-degree bend can exponentially increase the required force.

• Safety Factor: Always choose a machine with a rated capacity that is at least 1.5 times the maximum calculated pulling tension. This provides a crucial safety margin to account for unforeseen conditions and protects the cable from being overstressed.

For complex projects, we recommend a detailed pulling study. Our sales engineers can assist you in calculating the required tension based on your project's specific parameters, ensuring you get a machine that is both powerful enough and safely rated for the job.