Braided Shield Cable Preparation
Jan 27, 2002 12:00 PM
Braided-shield cables provide a flexible method of electrically shielding a cable. The braid also adds strength to the cable. Because of this, braided-shield cables are the best choice for cables used in mobile, remote or live applications. The drawback to using a braided shield, however, is the time and effort needed to prepare the cable for attaching a connector.
The standard approach is to completely unbraid the shield to free the conductors inside, and then twist the shield conductors together. The photos below detail this method. While there is nothing wrong with this method, it is tedious to unbraid the shield. Pulling and twisting the individual wires of the braid also subjects them to a great deal of stress, which often weakens the wires, breaking some of them in the process. In addition, the reformed shield conductor tends to shed wires causing potential electrical problems later on.
An alternate method provides a cleaner way to prepare the shield without subjecting the wires to stress, and it results in a cleaner, more manageable shield conductor.
The Traditional Method
Strip the jacket. With a pointed tool, carefully separate the braided shield.
Continue unbraiding the shield until it is completely fanned.
Remove any paper or plastic material between the braid and the conductors.
Twist the fanned shield into a single conductor.
The unbraided shield will have a natural twist to it. Try to follow this tendency.
Be careful not to break off the individual shield strands.
A Better Way
Strip the cable's jacket.
Push the braided shield away from the end of the wire to loosen the braid.
With a pointed tool, carefully push the strands to the side to make an opening in the braid.
Detail of the above instruction. Work slowly and the strands will move easily.
The size of the opening will depend on the flexibility of the inner conductors and your own skill.
Loop the tool around the conductors pull them through the opening in the braid. If there is a paper or plastic wrapper, you may be able to remove this before you create the opening in the braid.
Detail of the instruction above.
Continue pulling the conductors and filler through the opening.
The braided shield is now empty.
Detail of the note above showing all the conductors and filler pulled through the opening.
Cut the filler material.
Lightly squeeze and pull on the empty, loosened braid.
Detail of the above instruction. This step tightens the braid.
The cable is ready to be attached.
Detail of the finished effort.
The results of both methods. The pull-through method is on the left. The fanning method is on the right.
Photos by Marilyn Scherer