The Calculator uses Standard Equations based on Industry Practices.
Cable Tension Pull
Calculator for Straight Pulls
(Read reference material below for explanations.) by electrician2.com 

Select
Material 
Select
Size 
Coefficient
of Friction 
Weight
Multiplier 
Number of
Conductors 
Enter
Length in Feet 
Add/Sub
weight 
degrees of
incline 
incline
up/down 


Circular
mil area 
Total Weight of
one foot of wire(s) 
Maximum Pulling
Tension in Pounds 
Maximum
Pulling Length in Feet 
Reel
Tension in Lbs. 
Pulling
Tension in Lbs. 
**************** 

Cable Tension Pull Calculator
for Sheave and Sidewall Pressure (uses weight from above) 

Enter tension
into sheave 
Enter sheave Lb
Adder 
Enter diameter
of sheave in inches 
Enter sidewall
pressure multiplier (see the table below) 



Tension out of sheave 
Sidewall Pressure in Lbs. 
Maximum allowed
Sidewall Pressure in Lbs. 
**************** 

Uses weight from above. Values must be entered in top calculator first. 

Enter height to top roller in feet 
Enter tension for roller section 

Distance between rollers in feet 
Pulling with rollers all directions 

For Horizontal pulls  0 degrees 
For Straight up  90 degrees up 
For Straight down  90 degrees down 
For inclined angles X from horizontal  X degrees up 
For angles X down from horizontal (declination)  X degrees down 
For larger wires add 1.09, the default. This approximately compensates for the weight of the insulation. 
If weight of 1 ft of wire(s) or cable(s) is known use the multiplier
that gives the nearest weight per foot for all the wires or cables the
same as known value. The default weight with multiplier set to 1.00
is 0.321 Lbs per cubic inch of copper and 0.10 Lbs. per cubic inch of Aluminum.
The cubic inch per foot calculation is found from the circular mil
area for the selected size of conductor. The weight and not the circular
mil area is used in subsequent calculations for Pulling Tension.
For other weights that are lighter, for instance fiber optic cables, use
a negative multiplier. The weight multiplier uses the size of conductors
as a reference only. This way the calculator can be used for
calculating Pulling Tension for communications and fiber optic cables.
The Maximum Pulling Tension is calculated as 0.008 times the circular mil area for copper and 0.006 times the circular mil area for aluminum. The Maximum Pull Tension and Maximum Pulling Length are not adjustable and would not be correct for fiber optic cables, but the Pulling Tension based on weight and coefficient of friction would be correct, likewise for the curvature calculator. 



Less than 8 AWG  Greater than No. 8 AWG  
One Single Cable 



Two or More (parallel or plex) 





One Cable  500  
Two or more Cables  1000  


Single Pair  300  
Multipair  500 
Given:
L1 = 300 ft.
L2 = 200 ft.
H1 = 30 ft.
H2 = 30 ft.
H3 = 60 ft.
T1 is tension out of first sheave.
T2 is tension out of second Sheave.
T3 is tension out of third sheave.
T4 is total tension at end of pull.Cable is 3/c 500 kcmil copper 15 Kv Type MC corrugated approved for cable tray installation.
Cable O.D. is 3.60 inches.
Net weight per foot is 8.67 Lb.
Minimum Bending Radius is equal to 7xOD = 25.2 inches.
see NEC Section 33411(b)
Maximum Sidewall Pressure is 1000 per foot of bend radius for three conductor cable.
See table below.
With a radius of 3 feet for a sheave the maximum pulling tension is 3000 Lbs.
Rollers are 1 foot above tray.
Using Given Conditions to find total pulling tension at T4 and number and spacing of rollers between T1 and T2 and between T3 and T4.
Step 1
Set add multiplier to 1.91 to get 8.67 Lb/Ft for conductor weight
for 3 1/C 500 kcmil
Calculate pull tension off reel and first 30 feet. using top calculator
Coefficient of Friction = 0.15
Length = 30 feet
degrees of incline = 90
incline up/down = up
Calculated pull tension = 260 Lbs.
Calculated pull tension off reel is 217 Lbs.Step 2
Calculate pull tension at T1 using bottom calculator
Tension into sheave is 260 + 217
Sheave adder = 125 Lbs.
(Adder is the estimated force required to bend the cable around the sheave)
diameter of sheave is 72 inches
(Remember the larger the sheave diameter the less the sidewall pressure)
Calculated pull tension = 602 Lbs.Step 3
Calculate pull tension into T2 using top calculator
Coefficient of Friction = 0.15
Length in feet = 300 ft.
Angle of Bend = 0 degrees
Total Calculated pull tension = 390 Lbs.
Total tension into T2 sheave is 390 + 602 = 992 Lbs.Find Spacing for rollers between T1 and T2
using roller spacing estimator:
Height to top of roller = 1 ft.
Tension for roller section = 992 Lbs.
Calculated spacing = 30.25 ft.
300/30 = 10 rollers
Step 4
Calculate pull tension out of T2 Sheave using bottom calculator
Tension into T2 sheave is 992 Lbs.
Sheave adder is 125 Lbs.
Diameter of Sheave is 72 inches.
Calculated Pull Tension = 1117Step 5
Calculate pull tension into T3 using top calculator
Coefficient of Friction = 0.15
Length in feet = 30 ft.
Angle of Bend = 90 degrees up
Total Calculated pull tension = 269 Lbs.
Total tension into T2 sheave is 260 + 1117 = 1377 Lbs.Step 6
Calculate pull tension out of T3 Sheave using bottom calculator
Tension into T2 sheave is 1377 Lbs.
Sheave adder is 125 Lbs.
Diameter of Sheave is 72 inches.
Calculated Pull Tension = 1502Step 7
Calculate pull tension at T4 using top calculator
Coefficient of Friction = 0.15
Length in feet = 200 ft.
Angle of Bend = 0 degrees up
Total Calculated pull tension = 260 Lbs.
Total tension at T4 is 260 + 1502 = 1762 Lbs.Find Spacing for rollers between T3 and T4
using roller spacing estimator:
Height to top of roller = 1 ft.
Tension for roller section = 1762 Lbs.
Calculated spacing = 40.33 ft.
200/40 = 5 rollers
Bending Radii and Pulling Tensions 

Power Cables
Without Metallic Shielding
Power Cables With Metallic Shielding
The following recommendations are based on a study sponsored by ICEA. These recommendations may be modified if experience and more exact information so indicate. A. Maximum Pulling Tension On Cable
TM =0.006 x n x CM, for aluminum Done in Calculator where TM = max. tension, lb. n = number of conductors CM = cirmil area of each conductor
t = sheath thickness, inches D = overall diameter of cable, inches B. Maximum Permissible Pulling Length
where
C. Reel Back Tension
where
D. Pulling Tension Requirements in Tray
where Tout = tension for straight section at pulling end, lb. f = coefficient of friction (usually 0.15 for rollers) W = weight of one foot of cable(s) L = Length in feet Tin = pounds of tension in. For inclination (pulling up) the following formula applies:
T out = W L (sin ø + f cos ø
) + Tin pounds
For declinations (pulling down) the following formula applies: T out =  W L (sin ø  f cos ø
) + Tin pounds
E. Sidewall PressureF. Roller Spacing EstimatorSidewall Pressure = T / R Done in Calculator To estimate Roller Spacing the following can be used. G. Pulling Tensions Must Not Exceed The Smaller of These Values:
Pulling Eye:
T (Cu) = Number conductors x circular mills x .008 for copper
BasketGrip: T = 1000 lbs. per grip Sidewall Pressure: P = (300, 500 or 1000) pounds x radius of curve in feet depending on type and size of cable. 