Connectivity Guide

Fundamentals of cable engineering Components of a cable

Shielding

Shielding is basically an electrically conductive wrapping that is applied over the cable core, individual pairs, triads, or quads, or inner cable jacket. One of the shield’s primary purposes is to prevent electrical interference between cables and their components, pairs, triads, or quad groups. Since electrical interference does not only occur within the cable itself, shielding also provides protection from interference generated by external sources. In order for shields to be effective, they must be terminated properly as determined by end-use application requirements. Certain applications may only necessitate correct drain wire grounding, while others involve full circumferential termination requiring the use of round metal connectors. There are several types of shield designs for wire and cable.

• Steel wire braid:

mechanical protection see Lapp “SY” cables

• Tinned copper braid: electromagnetic protection (EMC) see Lapp “CY” cables

• Copper serve wires: more flexible than braid see Lapp “DP” cables

• Foil tape & braid: optimum coverage and flexibility

Bend radius

The bend radius is the degree of flexibility that a cable is capable of without being damaged. The minimum bend radius is expressed in terms of the total cable outer diameter. It is absolutely necessary to respect this value, particularly when using cable in continuous flexing applications.

3xD

r

D

10

Archived copy. For current information see: www.lappusa.com