Overview
IEC 62255-1:2003 is the IEC generic specification for multicore and symmetrical pair/quad outside plant cables used in broadband digital communications (high bit rate digital access telecommunication networks). It applies to polyolefin‑insulated symmetrical pair/quad telecommunication cables - filled or unfilled - with copper conductors intended for the local outdoor network. The standard defines characteristics, materials and construction principles, and the types of tests and test methods required to validate outside‑plant broadband cables.
Key Topics and Requirements
- Scope and cable types
- Covers local outdoor cables (typically 6–300 pairs) and drop cables (typically 2–6 pairs).
- Differentiates filled and unfilled designs and cable bandwidth classes (maximum referenced frequencies: 30 MHz, 60 MHz, 100 MHz).
- Conductor
- Solid annealed copper in accordance with IEC 60028.
- Nominal conductor diameter range: 0.5 mm to 0.9 mm.
- Joints in conductors permitted; joint tensile strength not less than 90% of adjacent conductor.
- Insulation and materials
- Polyolefin insulation (solid, cellular or multilayer systems allowed).
- Insulation thickness and type to suit termination and performance requirements.
- Optional water‑blocking/filling compounds to prevent longitudinal water migration.
- Cable structure
- Elements are twisted pairs or quads; variable lay lengths, oscillated pairing/quadding permitted.
- Provisions for screening, sheath, ripcord, strength members, color coding and identification as specified in detail specifications.
- Test methods
- Specifies categories of tests: electrical, transmission, mechanical/dimensional, and environmental.
- Installation considerations reference IEC 60794‑1‑1 guidance while requirements are finalized.
- Documentation
- Requires detail specifications to indicate color codes, construction dimensions and other local requirements.
Applications and Users
- Who uses it: cable manufacturers, telecom network designers, outside‑plant installers, test laboratories, procurement/specification authors and telecom operators.
- Practical uses: specifying and qualifying outdoor multicore pair/quad cables for local access networks, ensuring interoperability and environmental suitability (aerial, buried and drop installations), and guiding type testing for broadband performance up to 100 MHz.
- Benefits: provides a consistent framework to select materials, verify mechanical and transmission performance, and mitigate water ingress and environmental risks in outside‑plant broadband cabling.
Related Standards
- IEC 61156‑1 (multicore pair/quad generic spec for digital communications)
- IEC 60028 (copper conductor resistance)
- IEC 60304 (insulation colour codes)
- IEC 60794‑1‑1 (installation guidance for optical and cable systems)
- IEC 60811 series (material test methods)
Keywords: IEC 62255-1, multicore cables, symmetrical pair/quad cables, outside plant cables, broadband digital communications, polyolefin insulated, filled/unfilled cables, high bit rate access networks.