Installing cables and electrical wires often involve wire or cable pulling through conduits of various sizes. This seemingly simple task can become a real challenge, what with the many conditions surrounding it, such as the type of cable and distribution method, type and size of the raceway, and the overall dimension of the cable when combined with the pull string and other pulling tools used. This is why, in some situations, a cable lubricant is used to ensure that the wire is pulled without causing damage. Because any frays and cuts that happen along the way can become a long-term problem.
But aside from using cable lubricant Australia offers, observing the best practices in wire and cable pulling is necessary for a successfully accomplished job. Because re-pulling cables installed through walls is one of the worst back jobs in the construction and energy industry.
Best Practices in Pulling Cables
- Make sure there’s adequate clearance between the cable and conduit
A minimum quarter-inch clearance between the inner top of the conduit and the uppermost cable in the conduit is highly recommended. Clearance for large cable installations should go up to 1 inch. But if there are numerous bends that the wire has to go through, calculation for the conduit fill must be done.
- Calculate the jamming ratio
When 3 cables lie side by side in a conduit, jamming is likely to happen, even when a cable lubricant is used. This is especially true when the cables are pulled around bends or when the cable itself gets twisted while being pulled. To calculate the jamming ratio, the D/d ratio has to be slightly modified, with consideration to the manufacturing tolerances of a cable.
A value of 1.05D assigned to the inner diameter of the conduit will serve as the basis on whether or not jamming is possible. If the 1.05D/d ratio is less than 2.5, the cables may jam but clearance can be checked. If it’s bigger than 3.0, jamming will happen, and if it’s between 2.8 and 3.0, the potential for jamming is highest. Visit us at TEN The Energy Network
- Use the right lubrication
Cable lubricant in Australia is available in a huge variety because of the various types of cables, conduit surfaces, jacket materials, and other factors. This is why it is important to use only the best cable lubricant for the wire being used and the other conditions that must be considered.