Overview
IEC 61212-3-3:2006 is an IEC international standard that specifies requirements for industrial rigid round laminated moulded rods made from thermosetting resins for electrical insulation purposes. It covers material types, designations, manufacturing forms, dimensional tolerances and performance requirements for rods used in electrical, electronic and mechanical applications. The second edition (2006) adds application use and safety statements, updates document formatting and introduces type EP GC 43.
Key topics and technical requirements
- Scope and definition: Defines “round laminated moulded rod” (layers of impregnated reinforcement rolled on a mandrel, cured in a cylindrical mould and ground to size).
- Material types and designations: Types are designated by resin (e.g., EP = epoxy, PF = phenolic, SI = silicone) and reinforcement (e.g., GC = glass cloth, CC = cotton cloth, CP = cellulosic paper) plus a serial number and finish code (“A” = as produced, “B” = ground/turned). Example: Moulded rod, IEC 61212-3-3 – EP CC 41 – 25x1000 – A.
- Dimensional tolerances and straightness: Permissible deviations from nominal diameter (as moulded and ground/turned) and limits on departure from straightness are specified in tables - ensuring interchangeability and predictable machining behavior.
- Mechanical and electrical properties: Requirements include flexural strength (including values at elevated temperature), axial compressive strength, breakdown/ proof voltages (tests in oil at elevated temperature), insulation resistance after water immersion, thermal endurance, water absorption and density. Flammability monitoring (small-scale category test) is also included.
- Test methods: The standard refers to IEC 61212-2 for the test procedures and to IEC 61212-1 for general definitions and requirements.
Applications and practical use
- Used for specifying supplied insulating rods for:
- High-voltage bushings, supports and insulating spacers
- Rotating machinery and switchgear insulating components
- Mechanical parts where combined electrical insulation and structural performance are required
- Practical benefits: consistent material selection, predictable machining and performance, ease of procurement and quality control.
- Selection note: the standard states users must choose materials based on the actual application requirements (environment, temperature, mechanical load, humidity, flame risk), not on the specification alone.
Who should use this standard
- Electrical and mechanical designers, OEMs and manufacturers of insulating components
- Materials engineers and procurement/specification writers
- Test laboratories and conformity assessors
- Compliance and safety engineers in power and industrial equipment sectors
Related standards
Keywords: IEC 61212-3-3, insulating materials, laminated moulded rods, thermosetting resins, epoxy rods, phenolic rods, glass cloth reinforcement, electrical insulation standard, dimensional tolerances, breakdown voltage.
Open preview (PDF)Insulating materials - Industrial rigid round laminated tubes and rods based on thermosetting resins for electrical purposes - Part 3: Specifications for individual materials - Sheet 3: Round laminated moulded rods
