ISO/IEC TS 29125:2017/Amd 2:2024/Cor 1:2025

Overview

ISO/IEC TS 29125:2017/Amd 2:2024/Cor 1:2025 is a technical corrigendum to the international standard addressing telecommunications cabling requirements for remote powering of terminal equipment. This amendment and corrigendum update the guidelines on temperature rise management in telecommunications cables when carrying electrical current for powering devices remotely.

The document focuses on ensuring safe and efficient remote powering by detailing temperature increase limits for various cable configurations, helping prevent cable overheating and potential failures. It is particularly relevant for information technology and telecommunications professionals involved in designing, installing, and managing powered telecommunication systems.

Key Topics

• Temperature Rise Limits: Updated tables and figures provide precise temperature rise data for 1-pair cables with conductor diameters of 0.57 mm and 1.02 mm under different current loads and bundle sizes.
• Cable Configurations:
  • Temperature rise for cables in conduit and air environments.
  • Comparison between different bundle sizes and conductor diameters.
• Safety Guidelines: Advisories on maximum temperature rises to avoid overheating, especially in ambient temperatures reaching up to 50 °C.
• Cable Construction Impact: Notes on the influence of cable design and materials on temperature rise characteristics.
• Removal of ρ-Factor Clause: The document deletes previous assumptions related to constant ρ-factors, highlighting the need for recalculations in varied environmental conditions.

Applications

• Telecommunications Infrastructure: Provides essential guidance for cable designers and network engineers powering remote terminals such as IP phones, wireless access points, and IoT devices.
• Remote Powering Systems: Helps ensure compliance with safe operating temperatures for Power over Ethernet (PoE) and other remote powering technologies in telecommunication cabling.
• Cable Installation Planning: Aids installers in choosing appropriate cable sizes and bundle configurations to minimize temperature rises and maximize system reliability.
• Thermal Management Design: Enables facilities and network managers to predict thermal behavior and avoid risks of cable damage due to overheating in conduits and open-air environments.

Related Standards

• ISO/IEC 11801 – Generic cabling for customer premises, closely related for structured cabling design.
• ISO/IEC 30129 – Guidelines for remote powering of terminal equipment, complementary to TS 29125.
• IEEE 802.3af/at/bt – Power over Ethernet standards that address electrical powering within Ethernet cabling.
• IEC 60512 – Connectors for electronic equipment - relevant for understanding physical cabling components.

Keywords: telecommunications cabling, remote powering, temperature rise, Power over Ethernet, cable bundles, conductor diameter, cable temperature management, ISO/IEC TS 29125, conduit cable installation, IT cabling standards, telecommunications power safety, cable thermal limits.