IEC TR 62959:2021 PDF

Overview

IEC TR 62959:2021 is a Technical Report from the International Electrotechnical Commission (IEC) that provides guidance on shrinkage effects of optical fibre cables and their impact on cable and cable-element end termination. The report addresses cables built with standard glass optical fibres for telecommunication applications and explains how thermal and material-induced shrinkage can influence connectorization, splicing and other termination methods.

Key topics

• Scope and purpose
  • Guidance (informative) on characterising cable shrinkage and its effects on terminations rather than prescriptive normative requirements.
• Materials and mechanisms
  • Differentiation between reversible thermal expansion/contraction and irreversible thermal contraction (shrinkage) of plastic cable components.
  • Discussion of forces between cable elements caused by thermal changes.
• Cable types
  • Coverage includes simplex, loose-tube, unitube and other common telecommunication cable constructions.
• Termination cases
  • Examples and descriptions of practical termination scenarios: connectorized cables, hardened connectors, modules, dividers/fan-outs, splices and protective housings.
• Test methods and parameters
  • Recommended test methods for evaluating shrinkage with Method F11 and Method F17 highlighted.
  • Guidance on preconditioning, test parameters and shrinkage grades (including fibre protrusion grades).
• Recommended performance indicators
  • Tests to evaluate optical performance under thermal cycling, fibre protrusion, sheath shrinkage and element forces.
• Annexes
  • Extensive informative annexes with test templates, study results and tailored test recommendations for specific termination types.

Practical applications

Who uses IEC TR 62959:2021 and why:

• Cable manufacturers - to characterise shrinkage behavior during product development and for specification of shrinkage grades.
• Test laboratories - to apply recommended test methods (F11, F17) and report shrinkage/fibre protrusion results.
• System designers and installers - to select appropriate termination methods and protectors (modules, housings, hardened connectors) where shrinkage could affect reliability.
• Network operators and specifiers - to set procurement requirements and acceptance criteria for cable assemblies used in outdoor or varying-temperature environments.

Related standards (if applicable)

• This Technical Report complements IEC optical-fibre cable standards and test documents covering mechanical, environmental and optical performance. Users should consult relevant IEC normative standards for formal performance requirements and test procedures when specifying or qualifying products.

Keywords: IEC TR 62959:2021, optical fibre cables, cable shrinkage testing, fibre protrusion, connector termination, loose tube, simplex, shrinkage grades, test methods F11 F17.