Overview
IEC 62255-3:2005 is the sectional specification for filled multicore and symmetrical pair/quad outside plant cables used in broadband digital communications (high bit rate digital access telecommunication networks). It applies to filled cables with a metallic screen over the core, polyethylene jacket, copper conductors, and solid or cellular polyolefin insulation. Typical constructions cover 6 to 300 pairs and are classified by maximum reference frequency (30, 60 or 100 MHz). These outside plant cables are suitable for direct burial, duct installation, or aerial deployment (lashed or self-supporting).
Key topics and requirements
- Conductor
- Solid annealed copper, diameter 0.5–0.9 mm.
- Factory joints permitted; joint breaking strength ≥ 90% of unjointed conductor.
- Insulation
- Polyolefin-based; solid or cellular types permitted, with possible multi-layer skins.
- Thickness must ensure the finished cable meets specified performance and termination needs.
- Filling and flooding compounds
- Core and sheath interfaces must use water‑blocking materials (examples: polyethylene-modified petroleum jelly, thixotropic gels, superabsorbent polymers, extended thermoplastic rubber).
- Compounds must be compatible with other cable components.
- Screening / Armour
- Single aluminium tape (plastic-coated on at least one side) or dual tape system (aluminium tape + steel armour); minimum tape thickness 0.15 mm.
- Sheath
- Polyethylene (LLDPE, MDPE, HDPE) with (2.5 ± 0.5) % carbon black by weight; black outer sheath required.
- Identification & accessories
- Colour coding per IEC 60304 guidance; optional rip‑cord must be non‑hygroscopic/non‑wicking.
- Performance categories
- Standard includes electrical, transmission, mechanical/dimensional, and environmental requirements (see IEC 62255-1 for generic test methods and performance limits).
Applications and users
- Designed for outside plant telecommunication deployments: feeder and distribution cables for high-bit-rate access networks.
- Typical users:
- Cable manufacturers and product engineers (design & compliance)
- Network planners and specifiers (procurement and selection)
- Installation contractors (direct burial, duct, aerial)
- Test laboratories and quality assurance teams
- Regulators and standards bodies
Related standards
- IEC 62255-1 – Generic specification (referenced for tests and definitions)
- IEC 62255-3-1 – Blank detail specification for filled cables
- IEC 60304 – Standard colours for insulation
- IEC 60708-1 – Polyolefin insulated cables with moisture barrier sheath
Keywords: IEC 62255-3, filled cables, multicore cables, outside plant cables, broadband digital communications, high bit rate networks, water-blocking, polyethylene jacket, metallic screen, telecommunication cables.