1、BS 9120: 1988 UDC 621.396.669.8 0 British Standards Institution. No part of this publication may be photocopied or otherwise reproduced without the prior permission in writing of BSI British Standard Specification for Radio interference suppression filters of assessed quality: Generic data and metho
2、ds of test Filtres de qualit assure pour Iantiparasitage: donnes gnriques et mthodes dessai Gtebesttigte Funkentstrfilter: Fachgrunddaten und Prfverfahren British Standards Institution - BS9120 : 1988 Con tents Page Foreword Inside front cover Committees responsible Back cover Specification Section
3、one. Principles and mandatory procedures 1.1 1.1.1 1.1.2 1.1.3 1.1.4 1.1.5 1.1.6 1.1.7 1.1.8 1.1.9 1.1.10 1.1.11 1.1.12 1.1.13 1.1.14 1.1.15 1.1.16 1.1.17 1.2 1.2.1 1.2.2 1.2.3 1.2.4 1.2.5 1.2.6 1.2.7 General matters Scope Related documents Terminology Letter symbols, signs and abbreviations Graphic
4、al symbols Marking Eligibility for qualification approval Structurally similar components Delayed delivery Supplementary procedures for qualification approval Certified test records Ratings and characteristics Unchecked parameters Procedure to be followed in the event of a failure in a periodic test
5、 Release for delivery before completion of group B tests Component parts of filter assemblies Capability approval Test procedures General Measurement conditions Visual examination Dimensions and gauging Electrical test procedures Mechanical test procedures Environmental testing procedures Section tw
6、o. General rules for the preparation of detail specifications 2.1 Basic information 2.1.1 General 2.1.2 2.1.3 Detail specification number 2.1.4 2.1.5 Drawings 2.1.6 Ratings (including limiting conditions of use) 2.1.7 Related documents 2.1.8 Additional information that is not for inspection purposes
7、 2.2 Inspection requirements 2.2.1 General 2.2.2 Group A inspection 2.2.3 Group B inspection 2.2.4 Group C inspection 2.2.5 Group D inspection Originator of the detail specification Description of the component and intended application 1 1 1 1 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 5 5 5 5 6 6 11 11 11 11
8、11 11 11 11 11 11 11 12 12 12 12 Foreword This revised British Standard, which supersedes BS 9120 : 1984, has been prepared under the direction of the Electronic Components Standards Committee and is the generic specification for radio interference suppression filters in the BS 9000 series of standa
9、rds for electronic components of assessed quality. The revision is necessary to 2.3 Certified test records 2.3.1 General information 2.3.2 Attributes information 2.3.3 Measurements information 2.4 Instructions for ordering components 2.5 Low-volume, high-cost items Appendices A. Example of a certifi
10、ed test record B. Voltage proof test C. Measurement of leakage current (mains filter units only) D. Endurance tests for mains filter units E. Test for electrical shock hazard under normal conditions F. Tests on cable or cords and their anchorage to filter units G. Temperature rise at rated current t
11、est H. Spike test J. Measurement of connector contact resistance K. Dust and sand resistance test Tables I. Peak pulse voltages 2. Filter unit terminations 3. Insertion loss limits 4. Creepage and clearance limits 5. Test voltages for insulation resistance 6. Tensile test force for wire terminations
12、 7. Cable sizes and current ratings 8. Maximum sizes of cables and conduit for rated currents up to 16 A 9. Number of 24 h cycles 10. Inspection procedure for filters. Group A tests 11. Inspection procedure for filters. Group B tests 12. Inspection procedure for filters. Group C tests 13. Inspection
13、 procedure for filters. Group D tests 14. Values for endurance testing 15. Final inspection, measurements and 16. Number of specimens to be tested for rated 17. Minimum creepage and clearance distances 18. Torque values for screws and nuts 19. Cable pulling 20. Permissible cable and cord masses for
14、given rated current Figures 1. D.C. voltage proof test circuit 2. Class II single-phase filter units 3. Single-phase filter units other than class II 4. Three-phase filter units 5. Application of test voltage 6. Spike test circuit detail requirements voltage (mains filter units only) at rated voltag
15、es .- Page 12 12 12 12 12 12 16 18 18 19 21 21 22 23 24 25 2 3 4 5 5 6 7 8 10 13 13 13 14 15 20 21 21 21 22 22 22 18 19 19 19 20 23 incorporate additional requirements applicable to mains filter units. Appendix F describes tests on cables and cords and their anchorage to filter units, which may be r
16、equired in detail specifications. Compliance with a British Standard does not of itself confer immunity from legal obligations. BSI BS*LZO 0% Lb24bb9 0338986 bTT -.- _ BS 9120 : 1988 _ _ British Standard Specification for Radio interference suppression filters of assessed quality: Generic data and m
17、ethods of test Section one. Principles and mandatory procedures 1.1 General matters 1.1.1 Scope This British Standard establishes terms, methods of test and inspection procedures for radio interference suppression filters of assessed quality for use in electronic equipment and in the electrical powe
18、r supply to equipment, appliances, machines and apparatus. It includes safety requirements and tests which may be mandatory, according to the application. NOTE. The filter may form part of equipment to which other safety requirements apply, e.g. BS 415, BS 3456. This standard is intended to be used
19、in conjunction with BS 9000 and with related detail specifications in which are stated the dimensions, ratings, tests and requirements applicable to individual filters or series of filters. 1.1.2 Related documents BS 415 BS 923 BS 1701 BS 1852 BS 201 1 BS 2045 BS 3042 BS 3456 BS 3939 BS 4727 BS 5775
20、 BS 6001 Specification for safety requirements for mains- operated electronic and related apparatus for household and similar general use Guide on high-voltage testing techniques Part 2 Test procedures Specification for air filters for air supply to internal combustion engines and compressors other
21、than for aircraft Specification for marking codes for resistors and capacitors Basic environmental testing procedures Preferred numbers Specification for standard test fingers and probes for checking protection against electrical, mechanical and thermal hazard Specification for safety of household a
22、nd similar electrical appliances Guide for graphical symbols for electrical power, telecommunication and electronics diagrams Glossary of electrotechnical, power, telecom- munications, electronics, lighting and colour terms Specification for quantities, units and symbols Sampling procedures for insp
23、ection by attributes Part 1. Specification for sampling plans indexed by acceptable quality level (AQL) for lot-by-lot inspection BS 6217 BS 6299 BS 6500 BS 9000 BS 9070 Guide to graphical symbols for use on electrical equipment Methods of measurement of the suppression characteristics of passive ra
24、dio interference filters and suppression components Specification far insulated flexible cords and cables General requirements for a system for electronic components of assessed quality Part 1 Specification of basic rules and procedures Specification for fixed capacitors of assessed quality: generic
25、 data and methods of test Section 1 Principles and mandatory procedures Section 2 General rules for drafting detail specif icatins 1.1.3 Terminology For the purposes of this British Standard the general electrical and telecommunication terms and definitions given in the appropriate Part of BS 4727 a
26、pply. In addition the following specific terms and their definitions are applicable to the family of filters covered by this generic specification. The basic terms are inter-related and are used in the order shown below. 1.1.3.1 family. See 6.2.1 of BS 9000 : Part 1 : 1981. 1.1.3.2 filter unit. A co
27、mponent or an assembly of components intended to be connected in electric circuits for the purpose of reducing unwanted currents and voltages. 1.1.3.3 type. A basic shape or form of filter unit, e.g. lead-through filter. 1.1.3.4 series. A design of filter unit or inter-related filter unit covered by
28、 an individual detail specification. 1.1.3.5 variant. An individual filter unit within a series but having a feature OF features different from the standard filter unit. 1.1.3.6 specimen. An individual filter unit in a sample. 1.1.3.7 sealed filter unit. A filter unit in which the resistive, capacit
29、ive and inductive elements are housed in a casing or encapsulation. NOTE. Unless otherwise stated in the detail specification the resistive, capacitive and inductive elements will not have been subjected to separate qualification approval. 1.1.3.7(a) mains filter unit. A fi/ter unit intended for dir
30、ect electrical connection to the electrical supply mains. This unit may form part of an equipment. 1 BSI BS*9L20 01 BS9120 : 1988 1.1.3.8 unsealed filter unit. An unprotected filter unit assembly, or one having only a simple protective casing. NOTE. Unless otherwise stated in the detail specificatio
31、n, the resistive, capacitive and inductive elements will have been separately subjected to qualification approval to a BS 9000 detail specif ication. 1.1.3.9 insertion loss. The ratio of the voltage appearing across the line immediately beyond the point of insertion of a component or filter unit int
32、o a given transmission system, before and after the insertion. This ratio is expressed in decibels, dB, at a stated frequency or range of frequencies. 1.1.3.10 class I filter unit. A mains filter unit in which protection against electric shock does not rely on basic insulation only but which include
33、s an additional safety precaution in such a way that means are provided for the connection of conductive accessible parts to the protective (earthing) conductor in the fixed wiring of the installation ensuring that the conductive accessible parts cannot become live in the event of a failure of the b
34、asic insulation. NOTE. For filters intended for use with a flexible cord or cable, this provision includes a protective conductor as part of the flexible cord or cable. 1 .I .3.11 class I I filter unit. A mains filter unit in which protection against electric shock does not rely on basic insulation
35、only, but in which additional safety precautions such as double insulation or reinforced insulation are provided, there being no provision for protective earthing or reliance upon installation conditions. NOTE. Class II filters may be provided with means for maintaining the continuity of protective
36、circuits, provided that such means are within the filters and are insulated from accessible surfaces within the definition of class II filters. 1.1.3.12 class III filter unit. A filter, mounted inside other modules, for which the protection against electric shock relies on the protection afforded by
37、 such existing modules. 1 .I .3.13 class XI capacitor. A capacitor suitable for use in a mains filter unit where failure of the capacitor would not lead to danger of electric shock and having a peak pulse voltage in service as given in-table 1. 1.1.3.14 class X2 capacitor. A capacitor similar to a c
38、lass XI capacitor except rated for a lower peak pulse voltage in service as given in table 1. Table 1. Peak pulse voltages Class XI x2 Peak pulsa voltage in service 1200 0.33 pF) 1400 1;1.3.15 class U capacitor. A capacitor suitable for use in a mains filter unit where failure of the capacitor could
39、 lead to danger of electric shock and rated for normal insulation requirements in countries where mains voltages up to 125 V are standard. 1.1.3.16 class Y capacitor. A capacitor similar to class U except that it is rated for normal insulation requirements in countries where mains voltages greater t
40、han 125 V and up to 250 V are standard. 1.1.3.17 mains frequency. 50 Hz unless otherwise stated. 1.1.3.18 leakage current. The maximum current that can flow to earth from a mains filter unit connected to the power supply in accordance with the manufacturers instructions. 1.1.3.19 live part. A conduc
41、tor that has a voltage relative to earth exceeding 34 V peak to peak. 1.1.3.20 accessible part. A part that can be touched by a test finger, including cases where a moderate force is necessary. 1.1.3.21 creepage distance in air. The shortest distances measured in air over the surface of insulation b
42、etween conductive parts. 1.1.3.22 clearance. The shortest distance measured in air between conductive parts. 1.1.3.23 earth terminal. A terminal provided as a termination for the earth protective conductor in the mains lead, to which can be connected such parts as are required to be connected to ear
43、th. 1.1.3.24 permanent earthing. An object is said to be permanently earthed when its electrical connection to an earthed electrode is rigidly and permanently secured throughout its whole length without the intervention of any circuit interrupting device and is protected from mechanical damage and c
44、orrosion, unless by its nature and construction such protection is unnecessary. NOTE. Appliances earthed through the earth conductor of a flexible cable or cord terminafing in a 3-pin plug are not regarded as permanently earthed. 9 1.1.3.25 extra low voltage (e.1.v). A voltage that does not exceed 5
45、0 V a.c., rams., between conductors or between any conductor and earth. 1.1.3.26 rated system voltage. The rated voltage of the supply to the apparatus in which a mains filter unit is intended to be fitted. 1.1.3.27 lower category temperature. The minimum temperature of the external surface for whic
46、h the filter unit has been designed to operate. NOTE. Terminations are considered to be part of the external surface. 1.1.3.28 upper category temperature. The maximum temperature of the external surface for which the filter unit has been designed to operate continuously. NOTE. Terminations are consi
47、dered to be part of the external surface. 1.1.3.29 rated current. The current assigned by the manufacturer to a filter unit. NOTE. More than one value of rated current may be assigned to a filter unir, depending upon the heat dissipation characteristics of the specified mountings. 1.1.3.30 rated tem
48、perature. The maximum ambient temperature at which a filter unit is intended to carry its rated current. 1.1.3.31 functional insulation. The insulation necessary for the proper functioning of the filter. 1.1.3.32 basic insulation. Insulation applied to live parts to provide basic protection against
49、electric shock. 1.1.3.33 supplementary insulation. Independent insulation applied in addition to basic insulation in order to provide protection against electric shock in the event of failure of basic insulation. 1.1.3.34 double insulation. Insulation comprising both basic insulation and supplementary insulation. 2 BSI BS*L20 CIL m Lb24bb 0338988 472 ia Power supply BS 9120 : 1988 Point of Input connection identification 1.1.3.35 reinforced insulation. A single insulation system, applied to live parts, that provides a degree of protection against ele
