ArcFM Solution Configuration Guide
Pulling Tensions

Version: 10.1

Resource Center Home

Given the amount of tension on cables going into a section of conduit (T1), the following equations determine the amount of tension on cables coming out of the conduit section (T2).

Note: T1 of the conduit's first section only is the reelback or initial tension.

In subsequent sections of conduit, T, of a preceding section of conduit is T1 of the next section of conduit.

T2 = Outgoing tension (lb)

T1 = Incoming tension (lb)

L = Length of conduit section (ft)

K = Effective coefficient of friction (dimensionless)

W = Total weight of cables (lb/ft)

T = Offset angle (degrees)

e = Base of natural logs (2.718)

a = Bend angle (radians) (see table below)

 

Degrees

Radians*

11.25

.196

22.50

.393

30

.524

45

.785

60

1.047

90

1.571

* 1 radian = 57.30

 

A. For straight horizontal pulls:

  

T2 = T1 + LWK

  

B. For straight upward pulls:

  

T2 = T1 + LW (sin T + K cos T)

  

C. For straight downward pulls:

  

T2 = T1 - LW (sin T - K cos T)

  

D. For horizontal, upward, or downward pulls around bends:

  

T2 = T1 eKa

 


Send Comment