It Must Be Ensured When Laying Cables That Every Kind Of Mechanical Stress Is Avoided.
Bending Loads The bending radii may never be less than the values provided by the cable manufacturer in the respective data sheets. At points that bend too much, the electrical properties of the cable change and reduce the transmission bandwidths and ranges. If manufacturer specifications are not available, then the following rule of thumb applies: With loose cabling, at least 15 times the external cable diameter and with fixed cabling, at least 10 times the external cable diameter.
Kink Stress The most extreme bending loads can cause the cable to break.
Torque Strains (twisting) These must never have an effect on the cable, as they drive the cable elements into one another and therefore impair the transmission properties.
Compressive Stress Compressive stress is caused by loads bearing down from above, fixed clamping or sharp cable kinking and must always be avoided, as otherwise the “loose” cable structure changes and the electrical transmission properties are impaired.
Tensile Stress This is only determined by the copper cross-section of the conductor, as all other materials are too soft. The cable may not be stressed more than 50N/mm² (Cu cross-section) as otherwise the conductors are stretched and the cross-section is reduced. If higher “pulling” forces are required, then cables with additional strain relief elements must be used.