Question on Cable Pulling calculations, particularly sidewall pressure

[stcalle]

In regards to cable pulling calculations, when calculating the sidewall pressure I found 3 different equations that vary based on the conductor configuration in the conduit ie)

one conductor --> normal equation
three single conductors --> cradled configuration equation
three single conductors --> triangular configuration equation

my question is, what would the equation be for four single conductors in a conduit, complex configuration?
(complex configuration is the term used for four single conductors in a conduit while calculating weight correction factor)


I could not find anything anwhere about this. What I did temporarily is use the sidewall pressure equation for three single conductors, cradled as I put in some parameters and found this equation to yield the worse case sidewall pressure.


thanks

 

[don_resqcapt19]

I don't recall the sidewall pressure calculation using the conductor configuration equation. I thought that was only used to find the pulling tension, but it does impact the side wall pressure as that is equal to the pulling tension divided by the radius of the bend in feet. I have the Southwire pulling calculation information at work, but not here at home and I could look at it on Monday....if I remember.
Don

 

[bob]

In regards to cable pulling calculations, when calculating the sidewall pressure I found 3 different equations that vary based on the conductor configuration in the conduit ie)

one conductor --> normal equation
three single conductors --> cradled configuration equation
three single conductors --> triangular configuration equation

my question is, what would the equation be for four single conductors in a conduit, complex configuration?
(complex configuration is the term used for four single conductors in a conduit while calculating weight correction factor)

thanks

Complex is used when the number of cables is 4 or more. For 1 single cable up to 3 single cables(4/0 Max) the max allowable tension out of the bend shall not exceed 300 times the radius of the bend in ft. For 2 thru six single cables random lay, multi-conductor cables up thru 6 conductors, or up to
6 single conductors twisted, the max allowable tension out of the bend shall not exceed 500 times the radius of the bend in ft. Info taken from Okonite Cable Company
Also 3 cables of equal diameter introduces the problem of Jam Ratio if the sum of the cable diameters
is close to the inside diameter of the conduit.

 

[stcalle]

thanks for the replies

don, yes the information I have been reading is mostly from the Southwire power cable manual. It only has the sidewall pressure equations for 3 instances, the ones i explained in my first post. I am unsure what to do in the event of calculating the sidewall pressure for "four single conductors in a conduit".

bob, thanks for the reply, but I am unsure of what you are saying in your explanation. The main problem I am having is what equation do I use to calculate the sidewall pressure for four single conductors in a conduit.

 

[bob]

thanks for the replies

don, yes the information I have been reading is mostly from the Southwire power cable manual. It only has the sidewall pressure equations for 3 instances, the ones i explained in my first post. I am unsure what to do in the event of calculating the sidewall pressure for "four single conductors in a conduit".

bob, thanks for the reply, but I am unsure of what you are saying in your explanation. The main problem I am having is what equation do I use to calculate the sidewall pressure for four single conductors in a conduit.

You use Complex.

 

[stcalle]

But I cannot find an equation for the sidewall pressure for a complex cable configuration. The southwire cable manual only has 3 sideall pressure equations for:

one conductor --> normal equation
three single conductors --> cradled configuration equation
three single conductors --> triangular configuration equation

I've looked on google to try to find an equation for complex but I have had no luck. I wanted to know if there is such a equation? Or should I just use the cradled or triangular configuration equations?

 

[don_resqcapt19]

stcalle,

It only has the sidewall pressure equations for 3 instances, the ones i explained in my first post.

I didn't remember that there were multiple formulas.
Don

 

[jimmac49]

http://www.polywater.com/pullplan.html

Polywater has a software program that will figure it for you.

Jim

 

[bob]

But I cannot find an equation for the sidewall pressure for a complex cable configuration. The southwire cable manual only has 3 sideall pressure equations for:

one conductor --> normal equation
three single conductors --> cradled configuration equation
three single conductors --> triangular configuration equation

I've looked on google to try to find an equation for complex but I have had no luck. I wanted to know if there is such a equation? Or should I just use the cradled or triangular configuration equations?

Check you messages. I sent you the same info as Jimmac 49.