UL 60939-3
Standard for Passive Filter Units for Electromagnetic Interference Suppression - Part 3: Passive Filter Units for Which Safety Tests are Appropriate

Edition Number:1SCC Approved:--
Edition Date:2016-07-22DOD Approved: --
Price Code:EANSI Approved: 2017-11-15


    1.1 Scope

    This specification covers passive filters used to attenuate unwanted radio-frequency signals (such as noise or interference) generated from electromagnetic sources.

    Both single and multi-channel filters within one enclosure or which are built on a printed circuit board forming a compact entity are included within the scope of this specification.

    Filters constructed of capacitive elements where the inductance is inherent in the construction of the filter are within the scope of this specification. Similarly, filters constructed of inductive elements where the capacitance is inherent in the construction of the filter are also within the scope of this specification. It is up to the manufacturer to state whether a given component is to be designed as a capacitor, an inductor or a filter. Filters can include also other components like resistors and/or varistors or similar components

    This specification applies to passive filter units for electromagnetic interference suppression for which safety tests are appropriate. This implies that filters specified according to this specification will either be connected to mains supplies, when compliance with the mandatory tests of Table 3 is necessary, or used in other circuit positions where the equipment specification prescribes that some or all of these safety tests are required.

    This specification applies to passive filter units, which will be connected to an a.c. mains or other supply (d.c. or a.c.) with a nominal voltage not exceeding 1 000 V a.c., with a nominal frequency not exceeding 400 Hz, or 1 500 V d.c.

    NOTE For a.c. use, IEC 60384-14 applies to capacitors which will be connected to a.c. mains with a nominal frequency not exceeding 100 Hz.

    This specification covers appliance filters (US) but does not cover facility filters, cord-connected filters or direct plug-in filters. These other filters will be covered by another sectional specification.

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    • Cover
    • Transmittal
    • Table of Contents
    • UL Preface
    • Deviations
    • IEC Foreword
      • PASSIVE FILTER UNITS FOR ELECTROMAGNETIC INTERFERENCE SUPPRESSION – Part 3: Passive filter units for which safety tests are appropriate
        • 1 General
          • 1.1 Scope
          • 1.2 Normative references
          • 1.3 Information to be given in a detail specification
          • 1.4 Terms and definition
          • 1.5 Marking
          • 1.6 Components
          • 1.7 Overcurrent protective devices
          • 1.8 Wiring and Insulation
          • 1.9 Protective Bonding Conductors
          • 1.10 Corrosion
          • 1.11DV.1 Live parts
          • 1.11DV.2 Switches and controllers
          • 1.11DV.3 Printed wiring boards
        • 2 Preferred ratings and characteristics
          • 2.1 Preferred characteristics
          • 2.2 Preferred values of ratings
        • 3 Test plan for safety tests
          • 3.1 Structurally similar filters
          • 3.2 Safety approval procedure
          • 3.3 Requalification tests
        • 4 Test and measurement procedures
          • 4.1 General
          • 4.2 Visual examination and check of dimensions
          • 4.3 Inductance measurement
          • 4.4 Earth inductors incorporated in filters
          • 4.5 Capacitance
          • 4.6 Insertion loss
          • 4.7 Insulation resistance
          • 4.8 Voltage proof
          • 4.9 DC line resistance or voltage drop at rated current
          • 4.10 Discharge resistance
          • 4.11 Robustness of terminations
          • 4.12 Resistance to soldering heat
          • 4.13 Solderability (for performance only)
          • 4.14 Rapid change of temperature (for performance only)
          • 4.15 Vibration (for performance only)
          • 4.16 Shock (for performance only)
          • 4.17 Container sealing (for performance only)
          • 4.18 Climatic sequence
          • 4.19 Damp heat, steady state
          • 4.20 Temperature rise
          • 4.21 Current overload
          • 4.22 Leakage current
          • 4.22DV.1 Leakage current test
          • 4.23 Protective conductor resistance
          • 4.24 Impulse voltage
          • 4.25 Endurance
          • 4.26 Charge and discharge (for performance only)
          • 4.27 Passive flammability
          • 4.28 Active flammability
          • 4.29 Solvent resistance of the marking
          • 4.30 Component solvent resistance (for performance only)
    • Annex A(informative)Calculation of leakage current
    • Annex B (normative) Test schedule for safety requirements only
    • Annex C (normative) Circuit for the impulse voltage test
    • Annex D(normative) Circuit for the endurance test
    • Annex E(normative) Declaration of design(Confidential to the manufacturer and the certification body)
    • Annex F(informative)Safety and performance tests qualification approval – Assessment level DZ
    • Annex P(informative)Additional components and material standards
    • Bibliography