IEC 61753-111-09:2021

Overview

IEC 61753-111-09:2021 is an international standard published by the International Electrotechnical Commission (IEC) that defines the performance requirements for sealed fibre optic closures designed for subterranean applications. As part of the IEC 61753 series on fibre optic interconnecting devices and passive components, this standard specifies minimum tests, severities, and measurement requirements needed for these closures to be classified under Category S – Subterranean according to IEC 61753‑1:2018.

This edition, released in 2021, supersedes the 2009 version and includes significant technical updates aligned with the latest industry practices and standards, reflecting advances in materials, testing methodologies, and fiber optic technologies.

Key Topics

• Scope and Classification: IEC 61753-111-09 focuses exclusively on sealed closures positioned underground that protect fibre optic cables and connections from environmental hazards.

• Test and Measurement Criteria:

  • Detailed test severities for UV light and fungus resistance to ensure long-term durability of materials.
  • Updated laboratory conditions harmonized to standard temperature controls (+23 °C ± 5 °C) in accordance with IEC 61300-1.
  • Vibration sealing tests comprising 1,000,000 cycles at 10 Hz frequency and 3 mm amplitude.
  • Inclusion of cable retention and axial compression tests with reduced loads for small-diameter cables and tubes.
  • Amendment of immersion tests for solvent and contaminant resistance, modifying diesel immersion parameters and removing kerosene tests.
  • Other mechanical tests including torsion, bending, and optical shock tests with specified cycle durations for reliable performance assessment.

• Optical Performance Standards:

  • Integration of B-657 fibre types with defined minimum bending radius requirements according to IEC 61756-1:2019.
  • Pass/fail criteria provide measurable thresholds for sealing integrity and optical signal retention.

• Installation and Handling:

  • Procedures for assembly, disassembly, and reconfiguration to ensure ease of onsite intervention and maintenance with reduced test cycle durations.

• Material Requirements and Safety:

  • Guidelines on materials to resist environmental degradation such as UV exposure, fungus, and chemical contaminants.
  • Emphasis on safe design for subterranean deployment.

Applications

IEC 61753-111-09:2021 serves as a performance benchmark for manufacturers, installers, and operators of fibre optic communication networks requiring sealed closures deployed underground. Typical applications include:

• Telecommunications Infrastructure:

  • Underground fiber optic network protection in metropolitan and rural contexts.
  • Distribution and track/spur joint enclosures ensuring optical link integrity beneath roadways or railway tracks.

• Data Centers and Network Hubs:

  • Shielding critical fibre optic terminations in subterranean facilities from moisture, contaminants, and mechanical stresses.

• Utility and Industrial Networks:

  • Safeguarding fibre optic cables used for SCADA and remote sensing systems in harsh underground environments.

By adhering to IEC 61753-111-09, stakeholders can assure the reliability, longevity, and performance of sealed fibre optic closures, thereby reducing maintenance costs and network downtime in subterranean deployments.

Related Standards

To fully leverage the requirements and criteria of IEC 61753-111-09, it is important to consider related standards, including:

• IEC 61753-1:2018 – General performance standards for fibre optic interconnecting devices and passive components, defining categories and test severities applicable across various products including sealed closures.

• IEC 61756-1:2019 – Specifications concerning bending radius and mechanical characteristics of optical fibres, critical for ensuring optic performance within closures.

• IEC 61300-1 – Standardized test methods for fibre optic interconnecting devices and passive components, establishing laboratory testing conditions referenced in this standard.

• IEC 60793-2-50 – Detailing fibre optic cable characteristics such as those for B-657 fibre types integrated into closure design standards.

IEC 61753-111-09 aligns with these standards to provide a comprehensive framework for testing and certifying the performance of sealed underground fibre optic closures.

Adherence to IEC 61753-111-09 helps ensure that sealed fibre optic closures meet rigorous performance criteria essential for sustaining high-quality fibre optic communication networks in subterranean environments. Manufacturers can use this standard to design products that excel in durability, environmental resistance, and optical integrity, thereby supporting the global advancement of resilient and efficient fibre optic infrastructures.