IEC 61935-2-21:2021

Overview

IEC 61935-2-21:2021 is an international standard published by the International Electrotechnical Commission (IEC) that provides a blank detail specification for Category 6 cords in IT cabling. It is specifically aligned with the Category 6 cabling requirements defined in ISO/IEC 11801-1, which governs generic cabling systems for customer premises. This standard defines the framework for preparing detailed specifications of balanced cords with transmission capabilities up to 250 MHz, supporting robust digital communication infrastructures.

By offering a standardized layout and style for detail specifications, IEC 61935-2-21 facilitates consistent testing and documentation of Category 6 cords across manufacturers, national organizations, and users. The document works in conjunction with related IEC standards such as IEC 61935-2, IEC 61156-1, IEC 61156-6, and IEC 60603-7 series, which cover cabling components and connector specifications.

Key Topics

• Scope and Purpose: The document provides a blank template to prepare specific detail specifications for Category 6 cords, ensuring compliance with transmission characteristics up to 250 MHz.
• Testing Specification Layout: Defines required sections such as cord description, construction details, characteristics (electrical, mechanical, environmental), and test configurations.
• Cord Description Requirements:
  • Specific category designation
  • Nominal impedance
  • Connector types and conductor materials
  • Screening and housing details
  • Environmental classifications (MICE: Mechanical, Ingress, Climatic, Electromagnetic)
• Material and Construction Standards: Includes sheath materials, nominal thickness, color coding, maximum diameters, and marking standards.
• Performance Characteristics:
  • Electrical: DC resistance, resistance unbalance
  • Transmission: insertion loss, near-end crosstalk (NEXT), return loss, propagation delay, differential phase delay (skew)
  • Mechanical: tensile strength, bending radii, flexure, twisting, crushing, impact, and shock resistance
  • Environmental: water immersion, dust exposure, temperature range
• Test Method References: Detailed references to IEC sectional and generic specifications ensure precise test setups and measurement procedures.

Applications

IEC 61935-2-21 is primarily used by:

• Cable manufacturers to develop and document Category 6 cords that meet international quality and performance standards.
• Testing laboratories to structure and verify compliance tests and performance validation processes.
• National standardization organizations for customizing detailed specifications within their regional or national markets.
• System integrators and end-users seeking standardized Category 6 cords that guarantee reliable, high-speed digital communication in enterprise and data center environments.

Typical applications supported by cords tested under this specification include:

• Structured cabling for office buildings
• Work area connectivity in high-speed networks
• Data transmission systems requiring signal integrity up to 250 MHz bandwidth
• Industrial and commercial environments where standardized cabling reliability is critical

Related Standards

IEC 61935-2-21 is designed to function alongside several key IEC and ISO/IEC standards, including:

• ISO/IEC 11801-1 – Generic cabling for customer premises, defining general cabling requirements.
• IEC 61935-2 – Specifies testing requirements for cords under the ISO/IEC 11801 framework.
• IEC 61156 series – Covers multicore and symmetrical pair/quad cables, detailing generic specifications and sectional specifications for cabling.
• IEC 60603-7 series – Details connector specifications for shielded and unshielded 8-way connectors handling data transmissions up to 250 MHz.
• IEC 60794-1-22 – Optical fibre cable test procedures focusing on environmental tests.
• IEC 62012-1 – Cables for harsh environments with generic specifications.

Together, these standards provide comprehensive guidelines for the design, testing, and certification of high-performance Category 6 cabling components and assemblies.

By implementing IEC 61935-2-21:2021, stakeholders ensure consistent, reliable, and internationally recognized testing and detail specification of Category 6 cords, suited for modern digital communications infrastructure. This facilitates interoperability, quality assurance, and market acceptance across global networks in enterprises and data centers.