IEC 61156-4:2009

Overview

IEC 61156-4:2009 - Multicore and symmetrical pair/quad cables for digital communications - Part 4: Riser cables - Sectional specification - is a sectional standard that defines requirements for riser cables intended for vertical building runs up to Category 5 (Class D) as defined in ISO/IEC 11801:1995. It is to be read in conjunction with IEC 61156-1:2002 (generic specification). This edition (2009) is a technical revision covering construction, electrical and transmission performance, mechanical and environmental tests, and flame/smoke behaviour for riser applications.

Key topics and technical requirements

• Cable types: individually screened or unscreened pairs/quads, with or without an overall common screen.
• Electrical/transmission characteristics: attenuation, velocity of propagation, NEXT (near-end crosstalk), FEXT (far-end crosstalk), characteristic impedance, structural return loss (SRL), mutual capacitance and unbalance parameters.
• Conductor and insulation:
  • Conductor: annealed bare or tinned copper; nominal diameter 0.50–0.65 mm (up to 0.80 mm if compatible with hardware).
  • Insulation: thermoplastic materials such as polyolefin, PVC, fluoropolymer, or low-smoke zero-halogen (LSZH); solid or cellular constructions permitted.
• Mechanical and dimensional tests: conductor/insulation/sheath elongation, tensile strength, crush, impact, repeated bending and dimensional tolerances.
• Environmental and safety tests: thermal ageing, cold bend, heat shock, flame propagation (single cable and bundled), smoke generation, acid gas evolution and toxic gas emission; special tests for cables in air-handling spaces.
• Installation and temperature ranges: recommended installation 0°C to +50°C; normal operating range –40°C to +60°C. Vertical installation may impose extra length requirements.

Practical applications and users

IEC 61156-4:2009 is relevant for:

• Cable manufacturers specifying and testing riser-rated Cat5/Class D multicore cables.
• Specifiers and system designers creating structured cabling for commercial and multi-storey buildings (vertical riser/backbone runs).
• Installers and contractors deploying riser cabling who must meet electrical, mechanical and fire-safety performance.
• Test laboratories and compliance bodies performing attenuation, NEXT/FEXT, flame and smoke tests.
  Note: cables covered are designed for communication voltages/currents and must not be connected to low-impedance mains sources.

Related standards

• IEC 61156-1:2002 (generic specification) - essential companion document.
• ISO/IEC 11801:1995 - defines Category 5 (Class D) cabling.
• IEC 60304, IEC 60344 - colour coding and conductor resistance calculation guidance.

Keywords: IEC 61156-4:2009, riser cables, Category 5, class D, multicore cables, screened pairs, LSZH, structured cabling, NEXT, FEXT, cable specifications.