Roundness

Illustrated explanation

Bending and compression change cable geometry

2Roundness
Bending and compression change cable geometryCallout 1: Micro / macro bends. Callout 2: Roundness. Callout 3: Cold flow. Local fibre deformation, larger cable curvature, ovality and slow sheath deformation are different mechanisms. A cable can look smoothly routed yet carry local compression damage. Current term: Roundness, callout 2. 1LocalLarge-scaleMicro / macro bends 2Roundness 3Cold flow
  1. Microbending / macrobending

    Small local bends differ from curvature over a longer length. Respect both optical bend and crush limits.

  2. RoundnessThis term

    An oval section has unequal diameters. Check the cable profile and tolerance against the entry’s sealing capability.

  3. Cable cold flow

    Under sustained compression, the sheath can slowly change shape. Review material, temperature and retained sealing or grip.

Local fibre deformation, larger cable curvature, ovality and slow sheath deformation are different mechanisms. A cable can look smoothly routed yet carry local compression damage.

Exaggerated conceptual shapes. Fibre loss, allowable ovality and cable deformation limits must come from the actual cable specification.

ReferencesIEC 60794-1-1:2023 — Optical fibre cables — Generic specificationIEC 62444:2010 — Cable glands for electrical installationsISO 472:2013 — Plastics — Vocabulary