IEC 60939-2:2005

Overview - IEC 60939-2:2005 (Passive filter units for EMI suppression)

IEC 60939-2:2005 is the sectional specification that defines test methods and general requirements for passive filter units used for electromagnetic interference (EMI) suppression when safety tests are appropriate. It supplements the Generic Specification IEC 60939-1 and applies to passive filters that will be connected to mains or other circuit positions where safety testing is required. The standard covers units intended for service at nominal voltages up to 1 000 V a.c. or d.c. and nominal frequencies up to 400 Hz. This edition (2005) incorporates the November 2005 corrigendum.

Key topics and technical requirements

• Scope & applicability: Filters within IEC 60939-1 scope that require safety testing (mains-connected or as specified by equipment standards).
• Test methods: Detailed procedures for safety and performance tests including (but not limited to) voltage proof, insulation resistance, insertion loss, capacitance and tan δ, temperature rise, impulse voltage, endurance, charge/discharge behavior, solderability, robustness of terminations and various environmental stress tests (vibration, shock, climatic sequences).
• Quality assessment: Requirements for qualification approval, sampling plans, lot-by-lot tests, periodic testing and approved records for production control.
• Preferred ratings & characteristics: Guidance on preferred values and ratings to harmonize specification and procurement.
• Annex material: Normative annexes include test schedules for qualification approval and safety-only regimes, circuit diagrams for impulse and endurance testing, and a declaration of design.

Practical applications - who uses IEC 60939-2:2005

• Manufacturers of passive EMI filter units who need to design and type-test products for safety and EMC compliance.
• Test laboratories performing qualification, routine and safety tests on mains-connected filters.
• Compliance and safety engineers specifying filters for equipment, ensuring filters meet required safety and performance criteria.
• Purchasing/specification teams seeking harmonized preferred ratings and documented quality assessment procedures.
• Regulatory and certification bodies assessing conformity with IEC requirements for EMI suppression components.

Related standards

This sectional specification is intended to be used with IEC 60939-1 and references several relevant IEC publications for test techniques and safety coordination, for example:

• IEC 60939-1 (Generic specification)
• IEC 60060-1 (High-voltage test techniques)
• IEC 60664 (Insulation coordination)
• IEC 60068 series (Environmental testing)
• IEC 60335-1 and IEC 60384-14 (equipment and capacitor sectional specs)

IEC 60939-2:2005 is a practical, prescriptive resource for ensuring passive EMI filter units meet both performance and safety test requirements in mains and safety-critical applications.