Overview
IEC 62255-5:2005 is the sectional specification for filled drop cables used in outside plant applications for broadband digital communications (high bit rate digital access telecommunication networks). It applies to 2–6 pair multicore or symmetrical pair/quad cables with a metallic screen over the core, thermoplastic (black) jacket, copper conductors and solid or cellular polyolefin insulation. These filled drop cables are intended primarily for direct burial and are classified by maximum reference frequency (30 MHz, 60 MHz, 100 MHz).
Key topics and technical requirements
- Cable construction and materials
- Solid annealed copper conductors, diameter 0.50–0.65 mm; factory joints permitted (joint tensile ≥ 90% of unjointed conductor).
- Conductor insulation: polyolefin, solid or cellular, possible multi-layer skins; thickness compatible with termination.
- Cable elements: twisted pairs or quads, assembled into a circular core; optional non-hygroscopic core wrapping.
- Screening and sheath
- Metallic core screen options: aluminium tape (≥ 0.15 mm), bronze tape (≥ 0.10 mm), or copper-clad steel tape (≥ 0.11 mm, conductivity ≥ 28% IACS). Tape may be flat or corrugated with overlapping edges.
- Sheath: thermoplastic (LLDPE/MDPE/HDPE or PVC), black with (2.5 ± 0.5) % carbon black by weight. Inner jacket may be used.
- Water-blocking and filling compounds
- Core and sheath interfaces filled with suitable water-blocking materials: polyethylene-modified petroleum jelly, extended thermoplastic rubber, adsorbent thixotropic gels, superabsorbent polymers (with/without carrier), or atactic polypropylene for flooding compounds.
- Rip-cord (when present) must be non-hygroscopic and non-wicking.
- Performance & testing
- Defines electrical, transmission (attenuation, return loss, NEXT, FEXT), mechanical/dimensional, and environmental requirements. Tabulated limits include conductor resistance, test voltages and transmission coefficients (PSNEXT, PSELFEXT, attenuation) referenced in the standard.
- Identification & packaging
- Outer sheath marking: manufacturer, year, pair count, conductor diameter. Packaging details and sectional-to-detail specification linkage are included.
Applications and who uses this standard
- Intended for outside plant drop cables connecting distribution points to customer premises in fibre-extended or copper-based broadband access networks.
- Primary users:
- Cable manufacturers and material suppliers (product design, production specs).
- Network operators and service providers (procurement and installation requirements).
- Test laboratories and certification bodies (compliance and acceptance testing).
- Engineers and spec writers preparing tender documents for direct burial outside plant infrastructure.
Related standards
- IEC 62255-1 (Generic specification)
- IEC 62255-5-1 (Blank detail specification for filled drop cables)
- IEC 62255 parts 2–4 (other outside plant cable types)
- IEC 60304 (insulation colour standards)
- IEC 60708-1 (polyolefin insulation and sheaths)
Keywords: IEC 62255-5, filled drop cables, outside plant cables, multicore cables, broadband digital communications, direct burial, water-blocking, screened cable, polyolefin insulation.