What is the Sidewall Pressure for cable installation ?

Sidewall pressure is the vector force that exists on the cable as it is pulled through a bend. Because thesurface area of the bend is smaller in small radius bends, that force is concentrated over a much smallerarea. Most of the time sidewall pressure is the limiting factor in a cable pull.Sidewall pressure is calculated as follows:

For one single-conductor cable or multiple-conductor cable under a common jacket SP =T—R
For three single-conductor cables, cradledSP = (3ω -2) ∙—T (3R)

where:
T = tension coming out of the bend in pounds
R = bend radius, in feet
ω = weight correction factor, dimensionless
SP = sidewall pressure in pounds/food


Weight Correction Factor

The configuration of cables can affect cable tension. A weight correction factor (w) isused in the tension equations to account for this effect. The value for the weight cor-rection factor is determined from the equations that follow:

1 cable (single) ω =1

3 cables (Triangular) ω =1/(1-(d/(D-d))^2)^0,5

3 cables (Cradles) ω =1+4/3*(d/(D-d))^2

4 cables or more ( complex) ω =1,4

ω=   weight correction factor
D=   inner diameter of conduit
d=   outside diameter of the cable

Sidewall Pressure (SWP)To prevent damage to a cable from pressure that develops when a cable is pulled around a bend under tension, the pressure must be kept as low as possible and should not exceed specified values. Sidewall pressure 5tension out of the bend divided by bend radius. Cable manufacturers generally recommend a maximum SWP of 500 lb./ft. for most 600 V and medium-voltage power cables

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