1、BRITISH STANDARD BS 6885:1988 Specification for Miniature cartridge fuse links for use on printed wiring boards UDC 621.316.923.2-181.4:621.3.049.75:620.1BS6885:1988 This British Standard, having been prepared under the directionof the Power Electrical Engineering Standards Committee, was published
2、underthe authority ofthe BoardofBSI and comes intoeffecton 31 August 1988 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference PEL/78 Draft for comment 86/27465 DC ISBN 0 580 16502 7 Committees responsible for this British Standard The preparation of this
3、 British Standard was entrusted by the Power Electrical Engineering Standards Committee (PEL/-) to Technical Committee PEL/78, upon which the following bodies were represented: Association of Supervisory and Executive Engineers ERA Technology Ltd. Electrical Installation Equipment Manufacturers Asso
4、ciation (BEAMA Ltd.) Electrical Power Engineers Association Electricity Supply Industry in England and Wales Engineering Equipment and Materials Users Association London Regional Transport The following bodies were also represented in the drafting of the standard, through subcommittees and panels: B
5、ritish Telecommunications plc Electrical Contractors Association Electronic Components Industry Federation Institution of Electrical Engineers Ministry of Defence Amendments issued since publication Amd. No. Date of issue CommentsBS6885:1988 BSI 12-1999 i Contents Page Committees responsible Inside
6、front cover Foreword ii Section 1. General 0 Introduction 1 1 Scope 1 2 Object 1 3 Definitions 1 4 General requirements 1 5 Standard ratings 1 6 Markings 1 7 General notes on tests 3 8 Dimensions and construction 3 9 Electrical requirements 4 Section 2. Standard sheet Standard sheet I. Fuse-links5mm
7、 15mm, time-lag (surge proof), low-breaking capacity 7 Appendix A Colour coding for cartridge fuse-links for use on printedwiringboards 10 Figure 1 Test fuse-base 5 Figure 2 Test fuse-base for breaking capacity tests 6 Figure 3 Dimensions of colour code bands 10 Table 1 Testing schedule 2 Publicatio
8、ns referred to Inside back coverBS6885:1988 ii BSI 12-1999 Foreword This British Standard has been prepared under the direction of the Power Electrical Engineering Standards Committee. It covers type tests and requirements for miniature cartridge fuse links for use primarily on printed wiring boards
9、. Other miniature cartridge fuse links are covered in BS4265 which has, wherever possible, been used as a basis for the present standard. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct applicatio
10、n. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 10, an inside back cover and a back cover. This standard has been updated (see copyright date) and
11、 may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS6885:1988 BSI 12-1999 1 Section 1. General 0 Introduction The automated assembly of electrical and electroniccircuits on printed wiring boards hasledto a requirement for miniature cartrid
12、ge fuse-links which have the performance level of existing5mm 20 mm types and are of a form suitable for automatic insertion into printed wiring boards. These new types have dimensions comparable with other passive components and may be provided with axial leads for packaging on reels. Section 1 of
13、this British Standard covers the general requirements and tests applicable to all types of miniature cartridge fuse-links covered by this British Standard. Section 2 consists of a standard sheet giving the requirements applicable to the type of fuse-link. 1 Scope This British Standard specifies dime
14、nsions and performance characteristics for miniature cartridge fuse-links primarily for use on printed wiring boards, for the protection of electric appliances, electronic equipment and component parts thereof, normally intended for use indoors. It does not apply to fuses for appliances intended to
15、be used under special conditions, such as in corrosive or explosive atmospheres. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Object The object of this British Standard is to: a) establish uniform requirements for cartridge fuse-links for use
16、 on printed wiring boards so as to protect appliances or parts of appliances in the most suitable way; b) define the performance of the fuse-links so as to give guidance to the designers of electric appliances and electronic equipment; c) define methods of test. 3 Definitions For the purposes of thi
17、s British Standard, the definitions given in clause3 of BS4265:1977 apply. 4 General requirements The requirements of clause4 of BS4265:1977 shall apply. 5 Standard ratings The requirements of clause5 of BS4265:1977 shall apply. 6 Markings The requirements of clause 6 of BS4265:1977 shall apply exce
18、pt that the information given in6.4 is replaced by the following: 6.4 Colour coding of miniature fuses. Further identification of the current rating and time/current characteristic by means of colour bands may be used. Such additional marking shall be in accordance with Appendix A of BS6885.BS 6885:
19、1988 2 BSI 12-1999 Table 1 Testing schedule Subclause of this standard unless otherwise stated Description Fuse-link no. 16 7 9 11 8 10 13 12 14 15 16 17 18 19 20 21 22 24 26 23 25 27 28 29 30 31 32 33 34 36 38 35 37 39 40 41 42 43 44 45 46 47 48 9.4 of BS4265:1977 Endurance test 9.2.2 of BS4265:197
20、7 Test at elevated temperature a 9.2.1 of BS4265:1977 Time/current characteristics: 10 I n 4 I n 2.75 I n 2.0 or 2.1 I n 9.3 of BS4265:1977 Breaking capacity tests: Rated breaking capacity 5 times the rated current 10 times the rated current 50 times the rated current 250 times the rated current 8.3
21、 End cap test and wire termination tests: Axial pull Bending b 8.5 of BS4265:1977 Soldered joints 6.2 of BS4265:1977 Legibility and indelibility of marking a Applicable only when specified on the standard sheets. b Applicable only to fuse-links provided with wire terminations.BS6885:1988 BSI 12-1999
22、 3 7 General notes on tests NOTETests according to this British Standard are type tests. 7.1 Atmospheric conditions for testing The requirements of7.1 of BS4265:1977 shall apply. 7.2 Type tests NOTEIt is recommended, that where acceptance tests are required, they are chosen from the type test in thi
23、s British Standard. The requirements of7.2 of BS4265:1977 shall apply except that7.2.2 is replaced by the following: 7.2.2 On the results of Test 5 above, the fuse-links shall be sorted in descending order of voltage drop, and numbered consecutively. Lower numbers being allocated to the fuse-links h
24、aving the highest voltage drop. Tests from these fuse-links shall then be made in accordance withTable 1 of BS6885. If a test is to be repeated, spare fuse-links having approximately the same voltage drop as the original fuse-links shall be used for the repeat test. 7.3 Fuse-bases for tests For test
25、s, other than breaking capacity tests, that require a fuse-base for mounting the fuse-links, a base according toFigure 1 shall be used. The contact force shall be between4N and6N. The flexible lead and terminal wires shall be of copper and have a cross-sectional area of1mm 2 ; the length of each of
26、the terminal wires shall be approximately500mm. For breaking capacity tests, a fuse-base according toFigure 2 shall be used. The contact force shall be between8N and12N. The flexible lead and terminal wires shall be of copper and have a cross-sectional area of6mm 2 ; the length of each of the termin
27、al wires shall be approximately500mm. Both types of base shall have a contact resistance, between each contact and a silvered brass piece having the same nominal dimensions and shape as the fuse-link to be tested, not greater than3m7 measured under the following conditions. a) In order to prevent th
28、e breakdown of thin insulating layers on the contacts, the e.m.f. of the circuit shall not exceed20mV (d.c. or a.c. peak). b) In order to prevent undue heating of the contacts, the current flowing shall not exceed1A. Metal parts of the fuse-base, except the spring and connectors, shall be made of br
29、ass. Brass parts of the fuse-base and of the brass piece for measuring contact resistance shall have a copper content between58% and70%. Contact parts shall be silver plated. NOTEFor fuse-links provided with wire terminations, such terminations should be removed as close to the cap as practicable be
30、fore performing those tests which require mounting of the fuse-link in a fuse-base. 7.4 Nature of supply The requirements of7.4 of BS4265:1977 shall apply. 8 Dimensions and construction 8.1 Dimensions The requirements of 8.1 of BS 4265:1977 shall apply. 8.2 Construction The fuse-element shall be com
31、pletely enclosed in the cartridge. Fuse-links shall have at each end a metallic cap of cylindrical form. Compliance is checked by inspection. 8.3 End caps and axial wire terminations The end caps, and also integral wire terminations or separate cap/wire terminations where fitted, shall be of non-cor
32、roding metal suitably protected against corrosion, and shall be effectively free from flux or other non-conducting substance on their outer surfaces. NOTENickel or silver plating is deemed to be adequate protection for brass end caps. Wire terminations, where fitted, shall comply with BS2011-2.1T re
33、garding solderability. The outer faces of the caps shall be substantially flat and perpendicular to the axis of the fuse-link. The caps shall be firmly attached so that it is not possible to remove them without damaging the fuse-link. Compliance is checked by inspection and by the following test.BS6
34、885:1988 4 BSI 12-1999 The samples are immersed in water for24h at a temperature between15 C and 35 C. After removal from the water the samples are tested according to their terminal configuration as follows. a) If the fuse-link is not provided with wire terminations, an axial pull steadily increasi
35、ng to5N is applied to each cap for1min. A suitable test apparatus for this purpose is given in Figure7 of BS4265:1977, and shall be used in cases of dispute. By using this apparatus, the test can be performed without distorting the end caps. b) For fuse-links provided with wire terminations, an axia
36、l pull steadily increasing to5N shall be applied through the terminations for1min. In either case, the caps shall remain firmly attached. In addition to the above axial pull test, fuse-links with wire terminations shall be subjected to a bending test in accordance with test Ub, method1 of BS2011-2.1
37、U:1984 on both terminations. The terminations and caps shall remain firmly attached. 8.4 Alignment The requirements of8.4 of BS4265:1977 shall apply. 8.5 Soldered joints The requirements of8.5 of BS4265:1977 shall apply. 8.6 Packaging Where fuse-links are packaged on continuous tapes for automatic h
38、andling, such packaging shall comply with BS6062-1. 9 Electrical requirements The electrical requirements of the fuse-links shall comply with clause9 of BS4265:1977. The fuse-bases used shall be as specified in7.3 of this British Standard. BS6885:1988 BSI 12-1999 5 NOTEAll linear dimensions are in m
39、illimetres with tolerances of0.1mm. Figure 1 Test fuse-base (see7.3)BS6885:1988 6 BSI 12-1999 NOTEAll linear dimensions are in millimetres with tolerances of0.1mm. Figure 2 Test fuse-base for breaking capacity tests (see7.3)BS6885:1988 BSI 12-1999 7 Section 2. Standard sheet Fuse-links 5 mm 15 mm, t
40、ime-lag (surge-proof), low-breaking capacity Standard sheet I Page 1 NOTECare should be taken to ensure that the prospective fault currents of the circuit are within the limits specified in this British Standard. This type of fuse-link is recommended for the protection of circuits in telecommunicati
41、on equipment or similar circuits with limited short-circuit current. Alignment: The dimensions of the gauge are: h = 30 mm; d = 5.38 mm 0.01 mm for types 1 and 2. h = 30 mm; d = 5.68 mm 0.01 mm for type 3 (see8.4 of BS4265:1977). Construction: The fuse-link shall be transparent. Ratedcurrent a Rated
42、voltage Maximum voltage drop V mV 32 mA 40 mA 50 mA 63 mA 80 mA 100 mA 125 mA 160 mA 200 mA 250 mA 315 mA 400 mA 500 mA 630 mA 800 mA 1 A 1.25 A 1.6 A 2 A 2.5 A 3.15 A 4 A 5 A 6.3 A 250 5 000 4 000 3 500 3 000 3 000 2 500 2 000 1 900 1 500 1 300 1 100 1 000 900 300 250 150 150 150 150 120 100 100 10
43、0 100 a Intermediate values shall be chosen from the R20 series according to BS2045. 8 blankBS6885:1988 BSI 12-1999 9 Fuse-links 5 mm 15 mm, time-lag (surge-proof), low-breaking capacity Standard sheet I Page 2 Marking Fuse-links shall be marked with: a) rated current; b) rated voltage; c) makers na
44、me or trade mark; d) characteristic symbol T. Pre-arcing time/current characteristic The pre-arcing time shall be within the following limits: Rated current 2.1 I n 2.75 I n 4 I n 10 I n Max. Min. Max. Min. Max. Min. Max. min ms s ms s ms ms 32 mA to 100 mA inclusive 2 200 10 40 3 10 300 Above 100 m
45、A to 6.3 A 2 600 10 150 3 20 300 Test at a temperature of 70 2 C A current of 1.1 I nshall be passed through the fuse-links for1h and they shall not operate. Breaking capacity Rated breaking capacity:35A or10I nwhichever is greater, tested with a.c. and using the circuit givenin Figure6 of BS4265:19
46、77, for the low-breaking capacity test. Endurance test 100 cycles at 1.2 times the rated current according to9.4 b) of BS4265:1977 followed by1hat1.5times the rated current according to9.4 c) of BS4265:1977.BS6885:1988 10 BSI 12-1999 Appendix A Colour coding for cartridge fuse-links for use on print
47、ed wiring boards The requirements of Appendix A of BS4265:1977 shall apply except that the information given inA.2 is replaced by the following: A.2 The colour bands shall extend at least over half the circumference of the fuse body and shall be evenly spaced and clearly separated as indicated inFig
48、ure 3. NOTEIn the case of transparent miniature fuses, the spacings still allow for the visibility of the fuse element. Figure 3 Dimensions of colour code bandsBS6885:1988 BSI 12-1999 Publications referred to BS 2011, Basic environmental testing procedures. BS 2011-2.1T, Test T. Soldering. BS 2011-2
49、.1U, Test U. Robustness of terminations and integral mounting devices. BS 2045, Preferred numbers. BS 4265, Specification for cartridge fuse links for miniature fuses. BS 6062, Packaging of electronic components for automatic handling. BS 6062-1, Specification for tape packaging of components with axial leads on continuous tapes. BS 6885:1988 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the in
