Conductor Pulling Tension
Capstan-equation pulling tension and sidewall pressure across bends.
Example
You enter
- Cable weight (lb/ft) 1.5
- Total run length (ft) 200
- Lubricant polymer
- Straight run before bends (ft) 100
- Bends angle (deg) 90, radius (ft) 2
You get
- Head-end tension 71 lb
- Max sidewall pressure 21 lb/ft
- Status ok
- Sidewall flag ok
Details, formula, and sources
Capstan equation T_out = T_in × exp(μ × θ) accumulated per bend; sidewall pressure T/R per bend; flagged against 5000 lb head-end / 1000 lb-per-ft sidewall thresholds.
Manufacturer pull-tension guides (Southwire, Encore Wire) by name.
Free at southwire.com and encorewire.com technical bulletins.
Estimate. AHJ and licensed electrician govern. Verify against the NEC edition adopted in your jurisdiction.
Field names used by the API: cable_weight_lb_per_ft, run_length_ft, lubricant, straight_run_ft, bends, tension_lb, max_sidewall_lb_per_ft, tension_flag, sidewall_flag
- Coefficient of friction 0.5 unlubricated / 0.2 lubricated unless user suppliesmanufacturer pull-tension guide typical