www bzfxw com BRITISH STANDARD BS EN 60939 2 2005 Passive filter units for electromagnetic interference suppression — Part 2 Sectional specification Passive filter units for which safety tests are app[.]
Scope
This Sectional specification applies to passive filter units for electromagnetic interference suppression which fall within the scope of the Generic Specification IEC 60939-1
This Sectional specification focuses on passive filter units that require safety testing Filters outlined in this specification must either be connected to mains supplies, necessitating compliance with the mandatory tests listed in Table 3, or be utilized in other circuit positions where the equipment specification mandates some or all of these safety tests.
This specification pertains to passive filter units designed for connection to an alternating current (a.c.) mains or other power supplies, with a maximum nominal voltage of 1,000 V a.c and a frequency limit of 400 Hz, or 1,000 V direct current (d.c.).
Normative references
The following referenced documents are indispensable for the application of this document
For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies
NOTE Components other than inductors and capacitors in the filter unit should fulfil requirements in the relevant
IEC 60060-1, High-voltage test techniques – Part 1: General definitions and test requirements
IEC 60062, Marking codes for resistors and capacitors
IEC 60068-1, Environmental testing – Part 1: General and guidance
IEC 60068-2-17, Basic environmental testing procedures – Part 2: Tests – Test Q: Sealing
IEC 60085, Thermal evaluation and classification of electrical insulation
IEC 60335-1, Safety of household and similar electrical appliances – Part 1: General requirements
IEC 60384-9, Fixed capacitors for use in electronic equipment – Part 9: Sectional specification: Fixed capacitors of ceramic dielectric, Class 2
IEC 60384-14, Fixed capacitors for use in electronic equipment – Part 14: Sectional specification: Fixed capacitors for electromagnetic interference suppression and connection to the supply mains
IEC 60664 (all parts), Insulation coordination for equipment within low-voltage systems
IEC 60938-1, Fixed inductors for electromagnetic interference suppression – Part 1: Generic specification
IEC 60939-1, Passive filter units for electromagnetic interference suppression – Part 1:
IEC 60940, Guidance information on the application of capacitors, resistors, inductors and complete filter units for radio interference suppression
IEC 61140, Protection against electric shock – Common aspects for installation and equipment
Information to be given in a detail specification
General
The detail specifications shall be derived from the relevant blank detail specification
Detail specifications must not impose requirements that are lower than those outlined in the generic, sectional, or blank detail specifications If stricter requirements are necessary, they should be documented in section 1.9 of the detail specification and clearly marked in the test schedules, such as with an asterisk.
NOTE The information given in 1.3.2 may, for convenience, be presented in tabular form
The following information shall be given in each detail specification and the values quoted shall preferably be selected from the appropriate clause of this sectional specification.
Outline drawing and dimensions
The article will include an illustration of the filter to facilitate easy recognition and comparison with other filters The detailed specification will provide dimensions and associated tolerances that impact interchangeability and mounting, with all dimensions preferably expressed in millimeters.
Numerical values for the body length, width, height, and wire spacing must be provided, or for cylindrical types, the body diameter along with the length and diameter of the terminations When a single detail specification encompasses a range of filters, their dimensions and associated tolerances should be organized in a table following the drawing.
In addition, the detail specification shall state such other dimensional information as will adequately describe the filter outline.
Mounting
The detail specification must outline the recommended mounting method for standard use, as well as the mandatory method for conducting vibration, bump, shock, and endurance tests If the filter design necessitates special mounting fixtures or heat sinks, the specification should detail these requirements, ensuring their use during vibration, bump, or shock testing Additionally, the specified heat sink is essential for the endurance test application.
For standard mounting recommendations, refer to section 1.8 "Additional information (not for inspection purposes)" in the detail specification It is important to note that using mounting methods different from those outlined in section 1.1 may result in reduced performance regarding vibration, bump, and shock resistance.
Ratings and characteristics
The ratings and characteristics shall be in accordance with the relevant clauses of this specification
Additional characteristics may be listed when they are considered necessary to specify adequately the filter for design or application purposes.
Marking
The detail specification shall specify the content of the marking on the filter and the package.
Terms and definitions
For the purposes of this Sectional specification, the terms and definitions given in 2.2 of
IEC 60939-1, as well as the following apply
1.4.1 a.c mains filter (or mains filter) passive filter unit designed essentially for application with a power-frequency alternating voltage supplied from the mains
Class X capacitors are designed for applications where their failure does not pose a risk of electric shock, yet they may still present a fire hazard.
Class X capacitors are categorized into three subclasses based on the peak voltage of impulses they can endure while in service These voltage impulses can result from external factors such as lightning strikes on nearby lines, as well as from switching operations in adjacent equipment or within the equipment utilizing the capacitor.
Table 1 – Classification of class X capacitors
Subclass Peak pulse voltage in service
Application Peak impulse voltage U p applied before endurance test
III High pulse application when C R ≤ 1,0 àF : U P = 4,0 kV when C R > 1,0 àF : U P = kV
X2 ≤ 2,5 kV II General purpose when C R ≤ 1,0 àF : U P = 2,5 kV when C R > 1,0 àF : U P = kV
1.4.3 class Y capacitor capacitor or RC-unit of a type suitable for use in situations where failure of the capacitor could lead to danger of electric shock
Class Y capacitors are further divided into four subclasses Y1, Y2, Y3 and Y4, as shown in
Table 2 – Classification of class Y capacitors
Subclass Type of insulation bridged Range of rated voltages Peak impulse voltage before endurance test
Y1 Double insulation or reinforced insulation
Basic insulation or supplementary insulation
< 150 V 2,5 kV NOTE For definitions of basic, supplementary, double and reinforced insulation, see IEC 61140
One Y-capacitor may bridge basic insulation One Y-capacitor may bridge supplementary insulation If combined basic and supplementary insulations are bridged by two Y2-, Y3- or
Y4-capacitors in series, they must have the same nominal value
For guidance on the application of capacitors bridging basic insulation, see 6.1 of IEC 60940
1.4.4 earth inductor inductor that forms part of the earth lead of a filter
Marking
See 2.4 of IEC 60939-1 with the following details
The marking information typically includes several key elements, prioritized by their significance: a) the manufacturer's name or trademark; b) the manufacturer's type designation or that specified in the detail specification; c) a recognized approval mark; d) rated voltage and frequency; e) identification of terminations and/or circuit diagram; f) rated current; g) rated temperature; h) climatic category; i) the year and month (or week) of manufacture, coded as per IEC 60062; and j) a reference to the detail specification.
The filter shall be clearly marked with the information in 1.5.1 a), b), c) and d), and also e) if this is not implied by b)
e) if this is not implied by b).
The package containing the filter(s) shall be clearly marked with all
National approvals may be indicated by lettering as an alternative to the approval mark.
Any additional marking shall be so applied that no confusion can arise
Preferred characteristics
General
The values given in detail specifications should preferably be selected from the following:
Preferred climatic categories
The filters covered by this specification are classified into climatic categories according to the general rules given in IEC 60068-1
The lower and upper category temperature and the duration of the damp heat, steady state test should be chosen from the following:
Duration of the damp heat, steady state test: 21 or 56 days
The severities for the cold and dry heat tests are the lower and upper category temperatures respectively
For guidance on the application of the categories described above, see IEC 60940.
Preferred values of ratings
Rated voltage (U R )
The preferred values of rated voltage are:
When selecting electromagnetic interference suppression filters, it is essential to ensure that their rated voltage meets or exceeds the nominal voltage of the connected supply system Additionally, the filter design must accommodate potential voltage increases of up to 10% above the nominal level.
NOTE X-capacitors can be used in a star connect.
Category voltage (U C )
The category voltage is equal to the rated voltage unless otherwise stated in the detail specification
Rated temperature
The rated temperature shall not be less than +40 °C.
Passive flammability
When specified, the minimum category of passive flammability permitted is category C
Primary stage of manufacture
Structurally similar filters
Filters can be deemed structurally similar if they share the same technologies for capacitors, inductors, and resistors, along with corresponding capacitive elements belonging to the same subclass, across their range of component values.
Certified records of released lots
According to section 3.5.1 of IEC 60939-1, the necessary information must be provided as specified in the detail specification and upon customer request Following the endurance test, the key parameters that require variable information include changes in insertion loss and insulation resistance.
Approval testing
Safety tests only approval
Table 3 and Annex B form a schedule limited to tests concerning safety only requirements
The safety-only approval schedule will utilize fixed sample sizes as outlined in section 3.4 of IEC 60939-1, specifically detailed in 3.4.3 and Table 3 of this sectional specification.
Before conducting approval testing, a declaration of design (Annex E) must be submitted to the certification body, detailing essential information and fundamental design aspects of the passive filters for which approval is requested.
If any component is modified after approval has been granted, the certification body must be notified (refer to Annex E) The decision to extend approval to include the modified component(s) lies with the certification body.
Qualification approval
Tables 4, 5, 6 and 7 are to be used when qualification approval is sought
Qualification approval testing procedures are outlined in section 3.5 of IEC 60939-1, detailing the schedule for lot-by-lot and periodic tests as specified in Tables 5, 6, and 7 Additionally, a fixed sample size schedule is provided in section 3.4.3 and Table 4 Both procedures require comparable sample sizes and non-conforming item counts, with consistent test conditions and requirements It is recommended to follow the qualification approval based on the fixed sample sizes in Table 4.
Sampling
To qualify filter types together, they must share the same rated voltage and component technology combinations, with corresponding capacitive elements belonging to the same subclass The required number of filters for each qualification within each group is detailed in Tables 3 and 4.
For each qualification, the sample must include an equal number of specimens representing both the highest and lowest total capacitance values within the specified range If only a single total capacitance value is considered, the total number of filters to be tested will be as indicated in Tables 3 and 4.
When selecting filters for a specific total capacitance, prioritize those with the highest rated current if multiple options are available If there are several inductance values at this rated current, opt for the filter with the highest inductance value.
NOTE "Total capacitance" in the paragraph above means the capacitance between the input terminations of the filter
Spare specimens are allowed under specific conditions: one specimen per value can replace a non-conforming item in group 0, one specimen per value can serve as a replacement for non-conforming specimens due to incidents not caused by the manufacturer, and an adequate number of specimens must be provided to conduct the repeat test as outlined in Note 8 to Tables 7.
The figures provided in Group 0 are based on the assumption that all subsequent groups apply; however, these numbers can be adjusted if necessary For instance, if a manufacturer opts to test multiple groups sequentially on the same specimens, particularly for costly filters, the numbers in Group 0 may be reduced Additionally, it is important to note that the figures for Group 0 do not account for the specimens needed for Groups 7 and 8.
When new groups are added to the qualification approval test schedule, the number of specimens needed for Group 0 must be increased correspondingly to match the number required for the additional groups.
Table 3 or 4 gives the number of specimens to be tested in each group together with the permissible number of non-conforming for qualification approval tests.
Tests
Before qualification approval testing, a 100% voltage proof test between terminations must be conducted as specified in Table 9, with a minimum duration of 1 second If a d.c test voltage is utilized for filters with class Y capacitors, it should be at least 1.8 times the a.c test voltage in Table 9 and last no less than 2 seconds Additionally, all non-conforming items must be eliminated from the lot before proceeding with qualification approval testing.
Approval of filters specified in one detail specification may necessitate one or more complete series of tests as outlined in Table 3 or Table 4 The tests within each group must be conducted in the specified order.
The whole sample with the exception of those specimens to be submitted to the tests of
Groups 7 and 8 shall be subjected to the tests of Group 0 and then subdivided for the other groups
A specimen found to be defective during the tests of group 0 shall not be used for the other groups
"One defective" is counted when a filter has not satisfied the whole or part of the tests of a group
Approval is granted when the number of non-conforming items remains within the specified limits for each group and does not exceed the total permissible non-conforming items.
NOTE Table 3 and Annex B or Table 4 and Annex A form the fixed sample size test schedule, where Table 3 or
Table 4 outlines the sampling details and allowable defectives for various tests, while Annex A and Annex B, along with the test details in Clause 4, provide a comprehensive overview of the test conditions and performance requirements, highlighting areas where choices must be made in the detailed specifications for test methods or conditions.
The conditions of test and performance requirements for the fixed sample size schedule shall be identical to those prescribed in the detail specification for the quality conformance inspection.
Quality conformance inspection
General
Before submitting for quality conformance inspection, a 100% voltage proof test must be conducted between terminations as specified in Table 9 The manufacturer determines the test details, ensuring a minimum duration of 1 second If a d.c test voltage is utilized for filters with class Y capacitors, it must be at least 1.8 times the a.c test voltage in Table 9 and last no less than 2 seconds Any non-conforming items must be removed from the lot before proceeding with lot-by-lot testing.
Formation of inspection lots
These tests shall be carried out on a lot-by-lot basis using sampling plans appropriate to the given assessment level specified in Table 5 and Table 6
Manufactured lots of separately identified filter units may be aggregated into inspection lots formed for such tests as are relevant to structural similarities between those manufactured lots b) Group C inspection
These tests shall be carried out on a periodic basis
Tests must be conducted on a number of specimens that align with the specified assessment level in Table 7 To minimize the number of specimens needed for a complete periodic test, manufacturers can opt to perform tests on multiple groups sequentially using the same specimens These specimens should accurately represent the filters produced during each testing period In future periods, additional filters from the approved production range will be tested to ensure comprehensive coverage of the entire approval range.
Requalification tests, as outlined in Annex B, may be necessary when there is a proposed change to the declared design specified in Annex E The certification body must be notified of these intended changes, after which it will determine if requalification tests are required.
Test schedule
The schedule for the lot-by-lot and periodic tests for quality conformance inspection is given in Table 4a and 4b of IEC 60939-2-1
The schedule for the lot-by-lot tests and criteria for requalification are given in Annex A and
Delayed delivery
In accordance with section 3.10 of IEC 60939-1, re-inspection requires checking insulation resistance as outlined in Group A inspection, while solderability must be assessed following the criteria of Group B inspection.
Table 3 – Tests concerning safety requirements only
Number of permissible non-conforming items per qualification Group Subclauses and test
Number of specimens tested per qualification 4) Per group 8)
4.3 Visual examinations 4.6 DC line resistance 4.7 Insertion loss (no load) 4.4 Voltage proof
4.5 Insulation resistance 4.8 Discharge resistance 1) Spares
4.3.2 Creepage distances and clearances 4.9 Robustness of terminations 4.10 Resistance to soldering heat 1) 4.25 Solvent resistance of the marking 2)
3A 4.19 Temperature rise or 5) 4.21.1 Endurance current 6) 7)
4.21.2 Endurance – voltage line terminations/case 1)
4.21.3 Endurance voltage between line terminations 7)
Footnotes: see end of Table 7
Table 4 – Sampling plan – Safety and performance tests qualification approval –
Number of permissible non-conforming items per qualification 4) Per group 8) Total Group Subclauses and tests
Number of specimens tested per qualification
4.3 Dimensions (gauging) 4.3 Visual examination 4.6 DC line resistance or voltage drop 4.7 Insertion loss (no load)
4.4 Voltage proof 4.5 Insulation resistance 4.8 Discharge resistance 1) Spares
4.3 Dimensions (detail) 4.3.2 Creepage distances and clearances 4.9 Robustness of terminations 4.10 Resistance to soldering heat 1) 4.25 Solvent resistance of the marking 2)
4.26 Component solvent resistance 2) 4.12 Rapid change of temperature 4.13 Vibration
3A 4.19 Temperature rise or 5) 4.21.1 Endurance – current 6) 7)
4.21.2 Endurance-voltage line terminations/case 1)
4.21.3 Endurance – voltage between line terminations 7)
Footnotes: see end of Table 7
Table 5 – Lot-by-lot-tests – Assessment level D / DZ
Group Subclauses and tests Inspection level IL
4.6 DC line resistance 4.7 Insertion loss (no load) 4.4 Voltage proof (test A only) 4.5 Insulation resistance (test A only) 4.8 Discharge resistance 1)
Group Subclauses and tests Inspection level IL
4.6 DC line resistance 4.7 Insertion loss (no load) 4.4 Voltage proof (Test A only) 4.5 Insulation resistance (Test A only) 4.8 Discharge resistance 1)
Footnotes: see end of Table 7
Table 6 – Lot-by-lot test – Safety tests only approval
Subclause and test 13) Conditions of test 13) Sample size
4.3 Visual examination 100 % 14) Any marking on the filter shall be legible and correct
Method for test C: 16) No permanent breakdown or flashover Footnotes: see end of Table 7
Table 7 – Periodic tests – Assessment level D / DZ
Number of non- conforming items 8)
Subclauses and tests Total sample 4)
4.3 Dimensions (detail) 4.3.2 Creepage distances and clearances 4.9 Robustness of terminations 4.10 Resistance to soldering heat 1) 4.25 Solvent resistance of the marking 2)
4.26 Component solvent resistance 2) 4.12 Rapid change of temperature 4.13 Vibration
4.21.2 Endurance – voltage line terminations/case
4.21.3 Endurance – voltage between line terminations 7)
2) If required in the detail specification
3) Whichever is required in the detail specification
4) See 3.4.3 for the structural similarities which are necessary before filters may be qualified together
The three numbers in each box of the table indicate in descending order the numbers applicable for specimens within the following current limits:
”Current” in this context is the sum of the rated current(s) carried by the leads for the individual phases, N excluded
When a range includes filters across multiple classifications, the number of specimens chosen will correspond to the classification that contains the majority of values within that range.
The numbers in Group 0 exclude the numbers of specimens required for Groups 7 and 8
5) For filters with rated current > 0,5 A only
6) For filters with rated current ≤ 0,5 A
7) See 4.21.4 for the option of combining the tests of Groups 3A and 3C
8) When zero non-conforming items are required and one non-conforming item is obtained, all the tests of the group shall be repeated on a fresh sample and then no further non-conforming items are permitted This provision is not applicable for Groups 7, 8 and C7, or when the non-conforming items obtained in any group are due to failure of the voltage proof test between line terminations and case For Tables 3 and 4, the non- conforming item obtained in the first sample shall be counted for the total non-conforming items permitted in the right hand column
9) This test may be carried out on electrically defective filters or detached terminations provided they have received all the processing which would be carried out on a completed filter Group 0 or Group A tests are omitted for filters intended to be submitted to this test
10) Not applicable to filters with capacitors of Subclasses X3 and Y3
11) The tests of this group or subgroup may be omitted if the capacitors in the filter across which the test voltages will appear are separately encapsulated and have been qualified to a detail specification under IEC 60384-14
12) Total number of non-conforming items of the groups 1 through 8
13) Clause numbers of test and conditions/requirements refer to 4
14) May be carried out as end-of-line testing
16) To be required in the detail specification
This Clause supplements the information given in Clause 4 of IEC 60939-1.
Earth inductors incorporated in filters
Earth inductors incorporated in filters shall meet the requirements of the relevant specification(s) See also 2.2.19 of IEC 60938-1.
Visual examination and check of dimensions
Voltage proof
Test circuit for d.c tests
Unless otherwise specified in the detail specification, R 1 shall be large enough to limit the charging current to 50 mA maximum
Unless otherwise specified in the detail specification, R 2 shall limit the discharge current to
Applied voltage
The voltages given in Table 9 shall be applied between the measuring points of Table 1 of
IEC 60939-1 specifies that qualification approval and periodic testing require a duration of 1 minute, while lot-by-lot quality conformance testing is set for 2 seconds The timing for these tests begins when 90% of the test voltage is applied across the test terminals.
The method of applying the test voltage for Test C shall be given in the detail specification
For qualification testing, the foil method of 4.5.2.1 of IEC 60939-1 shall be used
Attention is drawn to the fact that repetition of the voltage proof test may damage the filter
Attention is drawn to the fact that for some tests it may be necessary for the detail specification to prescribe that resistors or varistors should be disconnected
Range of rated voltages line/line (Test A) or line/ground (Test B or C)
NOTE C is the capacitance measured at 1 kHz between the relevant test terminations All a.c test voltages are r.m.s and 50 Hz or 60 Hz, unless otherwise specified in the detail specification
Insulation resistance
Temperature correction
When measurements are taken at temperatures other than 20 °C, it is essential to record the specific temperature A correction must then be applied to the measured value by using the designated correction factor outlined in the capacitor sectional specification for the applicable dielectric or provided in the detail specification.
DC line resistance or voltage drop at rated current
DC line resistance
When employing a d.c measuring method with an applied voltage under 10 V, the resistance between each input terminal and its corresponding output terminal must be measured and should not surpass the limits outlined in the detail specification Additionally, the detail specification may indicate specific connection points between the terminals and the measuring instrument.
Discharge resistance
Robustness of terminations
3A 4.19 Temperature rise or 5) 4.21.1 Endurance current 6) 7)
4.21.2 Endurance – voltage line terminations/case 1)
4.21.3 Endurance voltage between line terminations 7)
Footnotes: see end of Table 7.
Resistance to soldering heat
Test conditions
There shall be no pre-drying.
Intermediate inspection, measurements and requirements
The measurements after this test are the intermediate measurements after the tests of
Group 1A and before the remainder of the tests of Group 1
The filters shall be visually examined according to 4.2 There shall be no visible damage
The d.c line resistance or voltage drop shall be measured according to 4.6 The value shall be within the limit prescribed in Group A2 of the detail specification.
Solderability
Test conditions
Ageing of 4 h dry heat at 155 °C shall be applied unless the detail specification specifies no ageing, or a different ageing procedure is specified in the detail specification
When method 2 is used, a soldering iron of size A shall be used.
Rapid change of temperature
Vibration
Test conditions
Endurance by sweeping shall be applied The following are preferred severities:
The displacement should be 0.75 mm or 98 m/s², whichever is lower, across frequency ranges of 10 Hz to 55 Hz, 10 Hz to 500 Hz, or 10 Hz to 2,000 Hz The preferred duration for testing is 6 hours, evenly distributed across the axes being tested.
The specification will outline the required severity and the appropriate mounting method For filters featuring axial leads designed for lead mounting, the distance from the body to the mounting point must be 6 mm ± 1 mm.
Intermediate inspection
The filters shall be visually examined and there shall be no visible damage.
Bump 24
Test conditions
The mounting method and the severity shall be specified in the detail specification
The following severities are preferred:
Total number of bumps: 1 000 or 4 000
Shock 25
Test conditions
The mounting method and the severity shall be specified in the detail specification
The severities given in Table 11 are preferred
Corresponding duration of the pulse ms
Intermediate inspection, measurements and requirements
The measurements after this test are the intermediate measurements after the tests of
Group 1B and before the remainder of the tests of Group 1
The filters shall be visually examined according to 4.2 There shall be no visible damage
The d.c line resistance or voltage drop shall be measured according to 4.6 The value shall be within the limit prescribed in Group A2 of the detail specification.
Container sealing
Test conditions
Filters must undergo either Test Qc or Test Qd as per IEC 60068-2-17, depending on the requirements Unless stated otherwise in the detail specification, Method 2 is to be utilized when Test Qc is conducted.
Climatic sequence
Initial measurements
The initial measurements for the climatic sequence are the measurements made in 4.10.2,
Dry heat 26
See 4.16.2 of IEC 60939-1 with the following details:
No measurements are required at the upper category temperature.
Damp heat, cyclic, first cycle
Cold 26
See 4.16.4 of IEC 60939-1 with the following details:
No measurements are required at the lower category temperature.
Low air pressure
This test is only performed if required in the detail specification It is not normally specified for mains filters
See 4.16.5 of IEC 60939-1 with the following details:
The test shall be made at a temperature of 15 °C to 35 °C and a pressure of 8 kPa, unless otherwise specified in the detail specification
For filters with a rated voltage exceeding 200 V, while still at the specified low air pressure, and during the last 1 min of the test period, the rated voltage shall be applied
There shall be no permanent breakdown, flashover or harmful deformation of the case.
Damp heat, cyclic, remaining cycles
Final inspection, measurements and requirements
See 4.16.7 of IEC 60939-1, with the following details:
Recovery shall be for 18 h to 26 h under standard conditions for measurement
The filters shall be visually examined according to 4.2 There shall be no visible damage and any marking shall be legible
The voltage proof test according to 4.4 shall be carried out with 66 % of the voltage as specified in Table 9 There shall be no permanent breakdown or flashover
The insulation resistance shall be measured according to 4.5 The value shall exceed 50 % of the applicable limit given in Table 10
The d.c line resistance or voltage drop shall be measured according to 4.6 The value shall be within the limit prescribed in Group A2 of the detail specification
The insertion loss at no load must be measured within 72 hours, following the guidelines outlined in section 4.7, and must comply with the specified requirements This measurement is not necessary for safety testing purposes.
Damp heat, steady state
Test conditions
No voltage shall be applied unless otherwise specified in the detail specification
When voltage application is prescribed, U R shall be applied to one half of the sample and no voltage shall be applied to the other half of the sample.
Final inspection, measurements and requirements
See 4.18.3 of IEC 60939-1 with the following details:
Recovery shall be for 18 h to 26 h under standard conditions for measurement
The filters shall be visually examined according to 4.2 There shall be no visible damage and any marking shall be legible
The voltage proof test according to 4.4 shall be carried out with 66 % of the voltage as specified in Table 9 There shall be no permanent breakdown or flashover
The insulation resistance shall be measured according to 4.5 The values for Test A, B and C shall not be less than 3,5 MΩ
The d.c line resistance or voltage drop shall be measured according to 4.6 The value shall be within the limit prescribed in Group A2 of the detail specification
Within a further 72 h, the insertion loss at no load shall be measured in accordance with 4.7 and shall meet the requirements prescribed in 4.7.
Temperature rise
Test method
If the filter's maximum current at the upper category temperature is non-zero, half of the specimens must be tested at this temperature using the maximum current, while the other half should be tested at the rated temperature with the rated current Conversely, if the maximum current at the upper category temperature is specified as zero in the detail specification, all specimens are to be tested at the rated temperature with the rated current.
The filters shall be connected to a power in such a way that all lines carry the test current at the same time
When testing 3-phase filters with an additional neutral line, two distinct test runs are required: first, the test current should flow through all three phases while excluding the neutral; second, the test current should pass through two phases along with the neutral, excluding one phase.
The filter must be positioned in a chamber that maintains an ambient temperature within ±3 °C of the test temperature An alternating current (a.c.) or a direct current (d.c.) equal to the root mean square (r.m.s.) value of the test a.c current should be applied during the testing process.
Once thermal equilibrium is achieved, the internal temperature of filters rated for currents up to 36 A will be assessed using the resistance method Additionally, the temperatures of components like inductors, capacitors, and varistors will be measured using the thermocouple method.
For filters with a rated current exceeding 36 A, the thermocouple method is required to measure the temperature of components like inductors, capacitors, and varistors, while the resistance method remains optional.
In agreement with the manufacturer, a specially prepared filter equipped with thermocouples may be submitted for testing
To determine the internal temperature (T₂) at thermal equilibrium, the measured resistance (R₂) between the input and output terminals at temperature T₂ is utilized alongside the initial measured resistance (R₁) at the test chamber temperature (T₁) at the start of the test, applying the appropriate formulae.
T 2 = R 2 / R 1 (225 + T 1 ) – (T 3 – T 1 ) – 225 (for aluminium) where T 3 is the temperature of the test chamber at the end of the test and T 1 , T 2 and T 3 are expressed in degrees Celsius
Where other metals are used for the inductor windings or lead-through elements the appropriate formula shall be stated in the detail specification
The resistance \( R_2 \) can be measured either after turning off the supply or continuously while the supply is active This is achieved using the superposition method, which involves injecting a low-value direct current (d.c.) into the winding alongside the load current.
2 Covers the worst case: one phase disconnected
The temperature of the hottest part of the case shall also be measured, preferably with an attached thermocouple
In agreement with the manufacturer a specially prepared filter equipped with thermocouple may be submitted for testing
The internal temperature T2 of the filter is measured while operating in an ambient environment at the rated temperature T1 To account for any variations in ambient temperature during testing, the factor (T3 – T1) is included for correction.
Impulse voltage
Initial measurements
Initial measurements have been made in Group 0 of Table 3 or Table 4.
Test conditions
Capacitors except for those of subclasses X3 and Y3, shall be submitted to an impulse voltage test
Each capacitor must endure up to 24 impulses of identical polarity, with a minimum interval of 10 seconds between each impulse The peak voltage values for these impulses are specified in Tables 1 and 2.
The front time t r is defined as: t r = (t 90 – t 30 ) x 1,67 according to 18.1.4 of IEC 60060-1
For the definition of the time to half-value t d see 18.1.6 of IEC 60060-1
The waveform will be determined by the test circuit parameters Details of the test circuit are given in Annex C
Before using the circuit, it is essential to verify its operation with C X values of 0.01 µF and 0.1 µF, along with the specified values for other circuit components listed in Table C.1 The rise time \( t_r \) and the half-value time \( t_d \) must fall within ±50% of the values provided in Table C.2 Additionally, the capacitors C X utilized for this verification should not be high permittivity ceramic types.
If the waveform indicates a damped oscillation, the peak-to-peak value, \$U_{pp}\$, must not exceed 10% of the peak voltage of the impulse, \$U_{CR}\$ (refer to Figure 1).
Requirements
There shall be no permanent breakdown or flashover
If an oscilloscope monitor displays three consecutive impulses without any waveform indicating self-healing breakdowns or flashovers in the capacitor, no additional impulses will be applied, and the capacitor will be deemed conforming.
A capacitor is deemed conforming if it has received all 24 impulses and at least three of them exhibit a waveform that confirms no self-healing breakdowns or flashovers Conversely, if fewer than three impulses meet the required waveform criteria, the capacitor is classified as non-conforming.
Endurance
Test conditions – current test
This test is not applicable to filters with rated current > 0,5 A See Tables 3 and 4, footnotes 4,
This test is omitted if a combined voltage/current endurance test is carried out according to 4.21.4
The filters must be installed in the test chamber using heat-sinking arrangements as specified in the detail specification, ensuring they are suitable for normal operation at the specified current and temperature during testing.
Once the chamber reaches the designated test temperature, the test current will be applied to the filters, operating at a frequency of either 50 Hz or 60 Hz, unless otherwise specified in the detail specification If a non-zero current is indicated for the upper category temperature in the detail specification, half of the sample will be tested at 1.1 times this current at the upper category temperature, while the other half will be tested at 1.1 times the rated current at the rated temperature If no such specification exists, the entire sample will be tested at 1.1 times the rated current at the rated temperature.
NOTE A fuse or other suitable device may be connected in the circuit of each filter to indicate if failure occurs
After 1 000 h, the filters shall be allowed to recover for 1 h to 26 h and shall then meet the requirements of 4.21.5.
Test conditions – voltage test, terminations/case
This test is inapplicable if the filter case is made of non-conductive material or if any line terminations are considered part of the case.
The filters will undergo a 1,000-hour endurance test at the specified upper category temperature, or at a higher temperature if indicated in section 4.19.2 During this test, a voltage of 1.7 times the rated voltage (U R) will be applied.
50 Hz or 60 Hz, except that once every hour the voltage shall be increased to 1 000 V r.m.s
The test involves applying either 50 Hz or 60 Hz voltage for 0.1 seconds to each filter separately, with the line terminals connected and the case and earth terminal linked through a 47 Ω ± 5 % resistor The circuit configuration is detailed in Annex D.
To prevent voltage transients and current surges during switching, the test circuit must be carefully designed This can be accomplished by discharging the filter's capacitance prior to switching to the new voltage, ensuring that the total transition time to 1,000 V and back remains within 30 seconds.
NOTE A fuse or other suitable device may be connected in the circuit of each filter to indicate if failure occurs
After 1 000 h, the filters shall be allowed to recover for 1 h to 26 h and shall then meet the requirements of 4.21.5.
Test conditions – voltage test between terminations
If a combined voltage/current endurance test is performed as per section 4.21.4, the separate test is not required Filters must undergo a 1,000-hour endurance test at the upper category temperature, or at a higher temperature specified in section 4.19.2 During the test, a voltage of 1.25 U R at the rated frequency is applied, with an hourly increase to 1,000 V r.m.s.
The test voltage of 50 Hz or 60 Hz, as specified, should be applied for 0.1 seconds to each filter individually across the terminals intended for mains supply connection, using a resistor of 47 Ω ± 5% For test voltages exceeding 100 Hz, a lower resistor value may be specified Refer to Annex D for the circuit details.
To prevent voltage transients and current surges during switching, the test circuit must be carefully designed This can be accomplished by discharging the filter's capacitance prior to switching to the new voltage, ensuring that the total transition time to 1,000 V and back remains within 30 seconds.
NOTE A fuse or other suitable device may be connected in the circuit of each filter to indicate if failure occurs
After 1 000 h, the filters shall be allowed to recover for 1 h to 26 h and shall then meet the requirements of 4.21.5.
Test conditions – combined voltage/current tests
Coaxial lead-through filters allow for the simultaneous application of both test voltage and current The circuit must be configured to ensure that current is continuously applied during the voltage switching process outlined in Annex D.
A combined endurance test of 1,000 hours may replace the tests specified in sections 4.21.1 and 4.21.3, provided it is detailed in the specification and conducted with the appropriate number of samples The filters must be mounted according to section 4.21.1 Half of the samples will be tested at the rated temperature with 1.1 times the rated current, while the other half will be tested at the upper category temperature with 1.1 times the specified current, which may be zero Additionally, a voltage must be applied as outlined in section 4.21.3 for Class X capacitors or in section 4.21.2 for Class Y capacitors.
NOTE A fuse or other suitable device may be connected in the circuit of each filter to indicate if failure occurs
After 1 000 h the filters shall be allowed to recover for 1 h to 26 h and shall then meet the requirements of 4.21.5.
Final inspection, measurements and requirements
The filters shall be visually examined according to 4.2 There shall be no visible damage and any marking shall be legible
The voltage proof test according to 4.4 shall be carried out with 66 % of the voltage as specified in Table 9 There shall be no permanent breakdown or flashover
The insulation resistance shall be measured according to 4.5 The value shall exceed 50 % of the applicable limit given in Table 10
The d.c line resistance or voltage drop shall be measured according to 4.6 The value shall be within the original limit prescribed in the detail specification
Within a further 72 h, the insertion loss shall be measured in accordance with 4.7 and shall meet the requirements prescribed in 4.7.
Charge and discharge
Initial measurements
The capacitance and tan δ shall be measured.
Test conditions
The filters shall be subjected to 10 000 cycles of charge and discharge at the rate of approximately one operation per second
Each cycle shall consist of charging and discharging the filter For a.c rated filters the test voltage shall be
Each filter shall be individually charged by applying the test voltage through a resistor with the value
To limit the charge current to 1 A or the specified higher current, the resistance value \( R \) can be calculated using the formula \( R = \frac{220 \times 10^{-6}}{C} \, \Omega \), where \( C \) represents the capacitance in farads as detailed in section 4.22.1 The greater resistance value should be used to ensure optimal performance.
Each filter must be discharged individually through a resistor, ensuring that the voltage change rate (dU/dt) remains between 100 V/às and 130 V/às.
If it is impossible to achieve a discharge rate of 100 V/às because of internal resistance in the filter, the filter shall be discharged through a short circuit.
Final measurements and requirements
The filter connected as a capacitor shall be measured and shall meet the requirements of Table 12.
Passive flammability
This test is applicable only if prescribed in the detail specification
The initial and final measurements will be specified in the detailed specification, adhering to the flammability requirements outlined in IEC 60939-1.
Solvent resistance of the marking
3A 4.19 Temperature rise or 5) 4.21.1 Endurance current 6) 7)
4.21.2 Endurance – voltage line terminations/case 1)
4.21.3 Endurance voltage between line terminations 7)
Footnotes: see end of Table 7
Table 4 – Sampling plan – Safety and performance tests qualification approval –
Number of permissible non-conforming items per qualification 4) Per group 8) Total Group Subclauses and tests
Number of specimens tested per qualification
4.3 Dimensions (gauging) 4.3 Visual examination 4.6 DC line resistance or voltage drop 4.7 Insertion loss (no load)
4.4 Voltage proof 4.5 Insulation resistance 4.8 Discharge resistance 1) Spares
4.3 Dimensions (detail) 4.3.2 Creepage distances and clearances 4.9 Robustness of terminations 4.10 Resistance to soldering heat 1) 4.25 Solvent resistance of the marking 2)
Component solvent resistance
3A 4.19 Temperature rise or 5) 4.21.1 Endurance – current 6) 7)
4.21.2 Endurance-voltage line terminations/case 1)
4.21.3 Endurance – voltage between line terminations 7)
Footnotes: see end of Table 7
Table 5 – Lot-by-lot-tests – Assessment level D / DZ
Group Subclauses and tests Inspection level IL
4.6 DC line resistance 4.7 Insertion loss (no load) 4.4 Voltage proof (test A only) 4.5 Insulation resistance (test A only) 4.8 Discharge resistance 1)
Group Subclauses and tests Inspection level IL
4.6 DC line resistance 4.7 Insertion loss (no load) 4.4 Voltage proof (Test A only) 4.5 Insulation resistance (Test A only) 4.8 Discharge resistance 1)
Footnotes: see end of Table 7
Table 6 – Lot-by-lot test – Safety tests only approval
Subclause and test 13) Conditions of test 13) Sample size
4.3 Visual examination 100 % 14) Any marking on the filter shall be legible and correct
Method for test C: 16) No permanent breakdown or flashover Footnotes: see end of Table 7
Table 7 – Periodic tests – Assessment level D / DZ
Number of non- conforming items 8)
Subclauses and tests Total sample 4)
4.3 Dimensions (detail) 4.3.2 Creepage distances and clearances 4.9 Robustness of terminations 4.10 Resistance to soldering heat 1) 4.25 Solvent resistance of the marking 2)
4.26 Component solvent resistance 2) 4.12 Rapid change of temperature 4.13 Vibration
4.21.2 Endurance – voltage line terminations/case
4.21.3 Endurance – voltage between line terminations 7)
2) If required in the detail specification
3) Whichever is required in the detail specification
4) See 3.4.3 for the structural similarities which are necessary before filters may be qualified together
The three numbers in each box of the table indicate in descending order the numbers applicable for specimens within the following current limits:
”Current” in this context is the sum of the rated current(s) carried by the leads for the individual phases, N excluded
When a range includes filters across multiple classifications, the number of specimens chosen will correspond to the classification that contains the majority of values within that range.
The numbers in Group 0 exclude the numbers of specimens required for Groups 7 and 8
5) For filters with rated current > 0,5 A only
6) For filters with rated current ≤ 0,5 A
7) See 4.21.4 for the option of combining the tests of Groups 3A and 3C
When zero non-conforming items are required but one is found, all tests for the group must be repeated with a new sample, and no additional non-conforming items are allowed This rule does not apply to Groups 7, 8, and C7, nor in cases where non-conforming items arise from a failure of the voltage proof test between line terminations and the case For Tables 3 and 4, any non-conforming item identified in the initial sample will be included in the total count of permitted non-conforming items listed in the right-hand column.
The test can be performed on electrically defective filters or detached terminations, as long as they have undergone all necessary processing typical for a completed filter It is important to note that Group 0 or Group A tests are not required for filters that are intended for this specific test.
10) Not applicable to filters with capacitors of Subclasses X3 and Y3
Tests for this group or subgroup can be excluded if the capacitors in the filter, where the test voltages will be applied, are individually encapsulated and have been qualified according to a detailed specification under IEC 60384-14.
12) Total number of non-conforming items of the groups 1 through 8
13) Clause numbers of test and conditions/requirements refer to 4
14) May be carried out as end-of-line testing
16) To be required in the detail specification
This Clause supplements the information given in Clause 4 of IEC 60939-1
4.1 Earth inductors incorporated in filters
Earth inductors incorporated in filters shall meet the requirements of the relevant specification(s) See also 2.2.19 of IEC 60938-1
Measurements of capacitance and tan δ shall be carried out in accordance with 4.2 in
4.3 Visual examination and check of dimensions
The filters shall be visually examined and dimensions checked according to 4.4 in
Creepage distances and clearances on the exterior of the filter, between live components of differing polarity or between live parts and a metal casing, must adhere to the minimum values specified in Table 8.
Table 8 – Creepage distances and clearances
U R ≤ 130 V 130 V< U R ≤ 250 V 250 V< U R ≤ 500 V 500 V< U R ≤ 760 V Points of measurement Creepage distance mm
Between live parts of different polarity
Between live parts and other metal parts over basic insulation
Between live parts and other metal parts over reinforced insulation
Further information may be obtained by reference to the full table in IEC 60335-1 For definitions of basic, double and reinforced insulation see IEC 61140
Compliance shall be checked by measurement according to the rules laid down in
IEC 60335-1 for measurements on the outside of the filter Additional requirements may be necessary, e.g for drip-proof and splash-proof filters
See 4.6 of IEC 60939-1 with the following details:
Unless otherwise specified in the detail specification, R 1 shall be large enough to limit the charging current to 50 mA maximum
Unless otherwise specified in the detail specification, R 2 shall limit the discharge current to
The voltages given in Table 9 shall be applied between the measuring points of Table 1 of
IEC 60939-1 specifies a qualification approval and periodic testing duration of 1 minute, while lot-by-lot quality conformance testing requires a duration of 2 seconds The timing for these tests begins when 90% of the test voltage is applied across the test terminals.
The method of applying the test voltage for Test C shall be given in the detail specification
For qualification testing, the foil method of 4.5.2.1 of IEC 60939-1 shall be used
Attention is drawn to the fact that repetition of the voltage proof test may damage the filter
Attention is drawn to the fact that for some tests it may be necessary for the detail specification to prescribe that resistors or varistors should be disconnected
Range of rated voltages line/line (Test A) or line/ground (Test B or C)
NOTE C is the capacitance measured at 1 kHz between the relevant test terminations All a.c test voltages are r.m.s and 50 Hz or 60 Hz, unless otherwise specified in the detail specification
There shall be no permanent breakdown or flash-over during the test period
See 4.5 of IEC 60939-1 with the following details:
The method of applying the test voltage for Test C shall be given in the detail specification
For qualification testing, the foil method of 4.5.2.1 of IEC 60939-1 shall be used
When measurements are taken at temperatures other than 20 °C, it is essential to record the specific temperature To ensure accuracy, the measured value must be adjusted by multiplying it with the designated correction factor specified in the capacitor sectional specification or the detail specification for the corresponding dielectric.
The insulation resistance shall not be less than the value given in Table 10
NOTE 1 C is the capacitance measured at 1 kHz between the relevant test terminations All a.c test voltages are r.m.s and 50 Hz or 60 Hz, unless otherwise specified in the detail specification
NOTE 2 Limits more severe and related to a dielectric may be given in the detail specification
For filters equipped with a discharge resistor, measurements must be conducted with the resistor disconnected If disconnecting the discharge resistor risks damaging the filter, the test should be skipped for lot-by-lot assessments However, for qualification approval and periodic testing, filters specifically manufactured without discharge resistors should be used if the resistor cannot be safely disconnected.
NOTE 4 For multiple filters comprising of a number of individual filter elements the limit be divided by the number of filter channels
4.6 DC line resistance or voltage drop at rated current
The detail specification will prescribe which of the following two tests shall be used
When employing a d.c measuring method with a voltage below 10 V, it is essential to measure the resistance between each input terminal and its corresponding output terminal, ensuring it does not surpass the limits outlined in the detail specification Additionally, the detail specification may indicate specific connection points between the terminals and the measuring instrument.
4.6.2 Voltage drop at rated current
A direct current (d.c.) equal to the root mean square (r.m.s.) value of the rated alternating current (a.c.) must be applied through the filter between all pairs of line terminals, unless specified otherwise in the detailed specifications, to ensure continuity as indicated in the circuit diagram.
Once thermal stability is achieved, unless otherwise specified, the voltage drop must be measured and should not exceed the limits outlined in the detailed specifications.
See 4.6 of IEC 60939-1 with the following details:
Before any measurement of insertion loss on filters containing ceramic capacitors, either before or after conditioning, the filters shall be preconditioned under the following conditions:
Exposure to elevated temperatures, as outlined in the detail specification, should last for 1 hour, followed by a recovery period of 24 hours (± 1 hour) under standard atmospheric conditions for testing, as detailed in section 4.1 of IEC 60384-9.
For measurements made after conditioning, this preconditioning shall follow the prescribed recovery and all the other final inspections and measurements
When capacitive and inductive filter elements are individually accessible, measuring the capacitors and inductors can serve as an alternative to assessing the insertion loss.
The detailed specification must outline the preconditioning requirements, the method for measuring insertion loss—including the dimensions affecting characteristic impedance and electrical length of jigs connecting the filter to the measurement system—whether measurements are conducted with the filter under no load or a specified load, the mode of measurement (asymmetric or symmetric), the terminating impedances, and the frequency range for measurements, preferably between 150 kHz and higher.
30 MHz); g) the minimum insertion loss or capacitance and inductance to be achieved at each frequency
When measurements are made after conditioning, the limit shall be 6 dB less severe than the limit applicable in Group A or Group 0
The detail specification shall prescribe relevant limits for capacitance (C) and inductance (L) together with relevant frequencies if L and C are measured as alternatives to insertion loss
See 4.8 of IEC 60939-1 with the following details:
The test method and degree of severity to be used shall be specified in the detail specification
The test for snap-on or other special terminations shall be specified in the detail specification
This test is not applicable to filters with flexible insulated leads longer than 50 mm, or to filters with terminations (such as snap-on contacts) not intended to be soldered
See 4.9 of IEC 60939-1 with the following details:
There shall be no pre-drying
4.10.2 Intermediate inspection, measurements and requirements
The measurements after this test are the intermediate measurements after the tests of
Group 1A and before the remainder of the tests of Group 1
The filters shall be visually examined according to 4.2 There shall be no visible damage
The d.c line resistance or voltage drop shall be measured according to 4.6 The value shall be within the limit prescribed in Group A2 of the detail specification
This test may be carried out on electrically defective filters or detached terminations provided they have received all the processing which would be carried out on a completed filter
See 4.10 of IEC 60939-1, with the following details:
Ageing of 4 h dry heat at 155 °C shall be applied unless the detail specification specifies no ageing, or a different ageing procedure is specified in the detail specification
When method 2 is used, a soldering iron of size A shall be used
See 4.10.2, 4.10.3 and 4.10.4 of IEC 60939-1 When Method 3 is used the soldering time shall be less than 3 s
See 4.11 of IEC 60939-1 with the following details:
Duration of exposure at the temperature limits:
The filters shall be visually examined and there shall be no visible damage
See 4.12 of IEC 60939-1 with the following details:
Endurance by sweeping shall be applied The following are preferred severities:
The displacement should be 0.75 mm or 98 m/s², whichever is lower, across frequency ranges of 10 Hz to 55 Hz, 10 Hz to 500 Hz, or 10 Hz to 2,000 Hz The recommended duration for testing is 6 hours, evenly distributed across the axes being tested.