The formula for calculating footage capacities of reels for round cable is shown below. A 5% factor and 95% traverse utilization have been built into the formula. Cables must be wound evenly to obtain consistency.
* Round off the result to the nearest whole number.
|
F = |
π |
{[B+( |
A – 2 x X – B | )*0.95 x D][ | A – 2 x X – B | ]*[ | 0.95 x C | ]*} |
| 12 | 1.9 - D | 1.9 - D | D |
Where:
F = Feet of cable on reel
A = Flange diameter, in inches
B = Drum diameter, in inches
C = Inside traverse, in inches
D = Cable diameter, in inches
X = This variable is defined as the distance between the cable and the outside edge of the reel flange. Clearance is equivalent to 1 inch or 1 cable diameter, whichever is the larger quantity.
Note: The NEMA formula does not cover paralleled or triplexed assemblies. Contact the cable manufacturer for the maximum footages of these assemblies.
