Overview
IEC 62255-2-1:2005 is an IEC blank detail specification for multicore and symmetrical pair/quad unfilled outside-plant cables used in broadband digital communications (high bit rate digital access telecommunication networks). Rather than prescribing a single cable design, it defines the layout, style and required information fields that national bodies, manufacturers or users should complete when preparing a formal detail specification for an unfilled cable type.
Keywords: IEC 62255-2-1, multicore cables, symmetrical pair/quad, unfilled cables, outside plant cables, broadband digital communications, blank detail specification.
Key topics and technical requirements
The standard organizes the detail specification into clearly numbered items and subclauses and specifies what information must be recorded or referenced. Key technical topics covered include:
- Identification and administrative data
- Document preparer, issue/date, availability, related documents and trade names.
- Cable description and construction (Clause 5 references)
- Conductor type and size, insulation material and diameter, colour code, element description, number of elements, make-up, protective wrapping, sheath material and thickness, strength members, identification and packaging.
- Electrical and transmission characteristics (Clause 6.1–6.2 references)
- Conductor resistance and unbalance, insulation and dielectric strength, insulation resistance, mutual capacitance and unbalance, characteristic impedance, return loss, attenuation and crosstalk (PSNEXT/PSELFEXT), screening attenuation and transfer impedance, maximum referenced frequency, velocity of propagation, delay skew.
- Mechanical and dimensional characteristics
- Elongation and breaking strength (conductor, insulation, sheath, cable), tensile and crush tests, bending/impact/cold-bend tests, sheath adherence and sheath integrity.
- Environmental and ageing tests
- Thermal oxidative stability, thermal ageing effects, water penetration, wicking, hygroscopicity, UV resistance, compound flow and compatibility with filling/flooding compounds.
- Formatting guidance
- Use of NA (not applicable) and NS (not specified) conventions where a characteristic does not apply or a specific value is not required; cross-references to sectional specification IEC 62255-2 and generic IEC 62255-1.
Applications and who uses it
IEC 62255-2-1 is intended for:
- Cable manufacturers preparing product detail specifications for unfilled outside‑plant multicore and pair/quad cables.
- National standards organizations and procurement teams creating nationally adopted or purchase specifications.
- Network designers, telecommunication operators and system integrators who require a formal, consistent specification for high bit‑rate outside‑plant cables.
- Test laboratories and quality assurance teams using the blank layout to record required test parameters and acceptance criteria.
Practical benefits: ensures consistent documentation, simplifies procurement and conformity assessment, and aligns cable specifications with the sectional (IEC 62255-2) and generic (IEC 62255-1) requirements.
Related standards
- IEC 62255-1 - Generic specification for multicore and symmetrical pair/quad outside plant cables.
- IEC 62255-2 - Sectional specification for unfilled outside plant cables (used in conjunction with 62255-2-1).
- Other parts of IEC 62255 series (filled cables, drop cables and their blank detail specifications).
Use IEC 62255-2-1 as the template to create clear, audit‑ready cable specifications that meet the broader IEC 62255 family requirements.