Overview
ISO/IEC 30129:2015/AMD2:2025 (Amendment 2) updates the international standard for telecommunications bonding networks in buildings and other structures. Prepared by JTC 1/SC 25, the amendment clarifies scope and terminology, adds a formal definition for bonding network (BN), updates normative references, and refines design and installation requirements for bonding conductors used to mitigate electromagnetic interference (EMI) and stabilize signal reference for telecom systems.
Key topics and technical requirements
- Purpose: specify requirements and recommendations for design and installation of connections (bonds) between electrically conductive elements to
- minimise d.c. and a.c. potential differences caused by electromagnetic disturbance and transients, and
- provide a reliable signal reference to improve immunity from EMI.
- Bonding network types: identifies four general types - star, ring, local mesh, mesh - and notes increasing suitability in that order (star → ring → local mesh → mesh).
- Installation rules:
- Bonding conductors must meet applicable minimum bend radius and shall not be coiled or doubled back.
- Bonding connectors and fastenings shall provide and maintain a d.c. contact resistance of ≤ 100 mΩ.
- Conductors for Telecommunications Bonding Backbone (TBB) should be installed without splices where possible; splices must be minimised and accessible.
- Impedance control formulas: several clauses standardize spacing/quantity calculations using expressions such as n = (l/6) rounded down to the nearest integer (replacing previous ROUNDUP formulas) for Rack Bonding Conductors (RBC), TBB, mesh bonding conductors, etc.
- Documentation: all bonding connections must be documented (drawings, schematics, termination details, photos). Consider electronic Automated Infrastructure Management (AIM) systems compliant with ISO/IEC 18598 for complex installations.
Practical applications
- Preventing equipment malfunction and improving EMI immunity in:
- commercial offices, data centers, telecom exchange sites, and access provider premises
- buildings undergoing construction or refurbishment where IT/telecom equipment will be installed
- Design and verification of building bonding schemes (PBB, TBB, BBC, RBC, TEBC) to support structured cabling, rack installations, and fiber/metallic network interfaces.
- Maintenance and audit processes to sustain telecom bonding performance over the life of a building.
Who should use this standard
- Telecom and structured cabling designers and consultants
- Facility and electrical engineers, data center architects
- Cabling installers and commissioning teams
- Standards compliance officers and asset managers
Related standards
Keywords: telecommunications bonding networks, bonding conductors, mesh bonding network, EMI mitigation, telecom installation, TBB, PBB, rack bonding conductor.
Open preview (PDF)Amendment 2 - Information technology - Telecommunications bonding networks for buildings and other structures
