The amount of pulling force that is exerted on a cable has a lot of effects on the cable operation. It is always observed that during installation where a pulling device is used to pull the cable, there a lot of mechanical stresses that cause damage to the cable. If a damaged cable is used in installation, the consequent effects may be so damaging. Determination of the maximum pull tension on a cable is based on the force exerted by the pulling device. Besides, it can also be evaluated by the strength of the conductors. When pulling the cable, it should be maintained that the maximum tension allowed is not exceeded.

When the conductor is being pulled through the conduit, pulling tension has to be calculated and then compared if it falls within the allowable range. In case the force used exceeds the cable tension limit, it is wise to consider reducing your pull force so that the installation is secure and successful.

All pulling devices are labelled with the manufacturer’s prescription on the allowable limit of tension which should not be exceeded by the pulling devices. The user should check and have deep knowledge on what limit its pulling machine operates on so that the prescription is not contravened. Some of the basic guides which should lead you to the appropriate maximum pulling tension of a device are below.

        i.            Machine pulling eye. Read what is published by the manufacturer as the rating which should not be exceeded. Fiber cables have a device through which a hook used for pulling the cable through a conduit is placed, this is known as the pulling eye. The size and the make of the pulling eye is supposed to help you determine the tension required for pulling.

      ii.            Basket grip. This is a loop-like structure at the cable end which is used in holding the pulling device. There are instances where the tension limit indicted can be exceeded but you should be done under a guide from the manufacturer.

    iii.            There are some cases where the tension limit which is permitted is not indicated, therefore it calls for a lot of care when handling a cable under such situations.

Effect of the incoming tension

The overall tension in a conductor pull is highly affected by the incoming tension. Because this tension replicates in many ways through the conductor, it has a lot of effects on the pulling tension overly. Therefore an accurate estimation should be done on the incoming tension so as to get an accurate probable pull tension. Here are the ways in which an incoming tension acts on a cable:

        i.            Off reel vertical pulling. It involves putting the reel below a conduit then a conductor is pulled into the conduit.

      ii.            Off reel horizontal pulling.  The conductor is fed into a conduit horizontally over a specific length.

The bending forces involved when the conductor is coming out of the reel must also be consider since all these contribute to the tension. All these considerations are helpful for your success in installation and smooth service.

At Nassau we have a myriad of cable pulling devices. If you need help with these devices or more information on how to handle cables, all you have to do is get in touch with us and we’ll be very happy to help you out.