Pulling Tensions

[Mike01]

question on pulling tensions if:
Tm = .008 x n x CM
(applies to both certian conductors)
Tm = maximum allowable tension in lbs.
n = number of conductors in cable (assumes equal tension in each conductor)
CM = circular mil area of each conductor.

my question is if you have conductors of different sizes? if you had multiple 350kcmil cables and a single 1/0 conductor would the CM be equal to circular mill area of the sum of the cables? Or would this method potentially place to much tension on the smaller conductor?

 

[BJ Conner]

The Okonit Cable Installation Manual has an equation thus.

Tm = 0.008 x n x CM


The manual also says:
"In pulling three single conductors of equal size that are not triplexed, a value of n equal to 2, rather than 3, should be used since two of the condcutors may sustain the total pulling tension. When more than three single conductors of equal size are pulled in parallel. the maximum tension should be limited to 60% of the value dtermined by the equation , with n representing the total number of conductors.
When pulling conductors of differen sizes, consult manufacturer."

So that would be call the cable manufacture first. Your maximum tension would be something less than

Tm= 0.6 x 0.008x ( 3 x 350,000 + 105,600) = 5,547Lbs

Sidewall pressure is waht damage cable more than tension. The key is soap, soap and more soap.