The type and size of the conduit are major determinants of the pull's difficulty and required equipment.

• Conduit Size (Fill Ratio): The National Electrical Code (NEC) provides strict guidelines on the maximum number of conductors a conduit can hold. The fill ratio—the percentage of the conduit's cross-sectional area occupied by the cables—is crucial. Overfilling a conduit increases friction, making the pull more difficult and potentially damaging the cable insulation. It also leads to poor heat dissipation, which can be a fire hazard. We always recommend using a conduit fill calculator during the planning phase.

• Conduit Type and Bends: Different materials, such as PVC, EMT, or rigid metal, have varying friction coefficients. A rigid metal conduit generally offers a smoother pull than PVC. The number of bends, especially 90-degree bends, exponentially increases friction and tension. The "360-degree rule" states that the total of all bends in a single pull should not exceed 360 degrees.