IEC 60708:2005

Overview - IEC 60708:2005 (Low‑frequency cables with polyolefin insulation)

IEC 60708:2005 defines requirements for low‑frequency telephone cables that use polyolefin insulation and a moisture barrier polyolefin sheath. The standard covers cables with copper conductors (filled or unfilled), with options for duct installation, direct burial or aerial use (including integral suspension strand). This edition is a technical revision and includes the August 2016 corrigendum.

Key SEO phrases: IEC 60708, polyolefin insulation, moisture barrier polyolefin sheath, low‑frequency cables, telephone cables, outdoor networks.

Key topics and technical requirements

IEC 60708 addresses general design, construction and performance requirements, including:

• Conductor: material, type, finish and continuity requirements (copper conductors).
• Insulation: polyolefin material options (solid or cellular), specified thicknesses and colour coding.
• Sheath and moisture barrier: polyolefin sheath materials, application, sheath marking and sealing of ends.
• Core construction: cabling elements, stranding, filling, spare pairs/quads, and core protection.
• Mechanical requirements: tensile strength, elongation, sheath integrity, adhesion tests and resistance to water penetration.
• Thermal & environmental: thermal oxidative stability (OIT), shrinkage, ageing, low‑temperature bending and weathering resistance.
• Electrical requirements: conductor resistance, insulation resistance, dielectric strength, mutual capacitance and unbalance.
• Transmission characteristics: added Subclause 7.8 for digital communication performance (applicable up to ~2 Mbit/s / 1 MHz).
• Colour codes and identification: normative annexes provide colour‑coding schemes for pairs, quads, units and sub‑units.

(Note: refer to the published standard for full test methods, limits and detailed clauses.)

Applications and practical use

IEC 60708 is intended for specification and assessment of local outdoor telephone networks and other low‑frequency copper cabling where moisture resistance and robust outdoor performance are required. Typical applications:

• Telephone and voice access cables for ducts, direct burial and aerial installations
• Local loop and last‑mile copper networks
• Cables used for low‑speed digital links (up to ~2 Mbit/s)

Benefits: standardized construction, consistent mechanical/electrical performance, moisture protection and simplified interoperability between manufacturers and network operators.

Who uses this standard

• Cable manufacturers (product design and quality control)
• Network operators and telecom planners (procurement and specification)
• Test laboratories and conformity assessors (type and routine testing)
• Installation contractors and asset owners (selection for specific environments)

Related standards

Normative references included in IEC 60708:2005 (examples)

• IEC 60028 (resistance for copper)
• IEC 60304 (standard colours for insulation)
• IEC 60811 series (common test methods for insulating and sheathing materials)
• IEC 60189‑1 (PVC insulated cables - test/method references)
• IEC 60794‑1‑2 (basic test procedures for optical fibre cables - referenced for some methods)

For full requirements, tests and limits, obtain the official IEC 60708:2005 publication (including corrigendum).