SANS 1433-1-2008 Electrical terminals and connectors Part 1 Terminal blocks having screw and screwless terminals《电气接线端和连接器 第1部分 配备有螺丝接线端和无螺丝接线端的接线盒》.pdf

1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA

2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any

3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-21176-9 SANS 1433-1:2008Edition 1.1 Any reference to SABS 1433-1 is deemed to be a reference to this standard (Government Notice No. 1373

4、of 8 November 2002) SOUTH AFRICAN NATIONAL STANDARD Electrical terminals and connectors Part 1: Terminal blocks having screw and screwless terminals Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 international code

5、+ 27 12 www.stansa.co.za Standards South Africa SANS 1433-1:2008 Edition 1.1 Table of changes Change No. Date Scope Amdt 1 2008 Amended to change the designation of SABS standards to SANS standards, to update the definition of “acceptable“ and referenced standards, to modify the key to figure 7 and

6、the footnote to column 1 of table B.2, to delete reference to the standardization mark, and to add a bibliography. National foreword This South African standard was approved by National Committee StanSA SC 67C, Electricity distribution systems and components Electrical accessories, in accordance wit

7、h procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. This document was published in June 2008. This document supersedes SABS 1433-1:1987 (first edition). SANS 1433-1:2008 Edition 1.1 1 Contents Page Foreword 1 Scope 3 2 Definitions . 4 3 Constructional require

8、ments . 5 4 Electrical and physical requirements 8 5 Packing and marking 10 6 Inspection and methods of test. 11 6.1 Inspection. 11 6.2 Sequence of testing and test conditions 11 6.3 Test for durability of markings 12 6.4 Test for conductor fit 12 6.5 Test for protection against electric shock (prot

9、ected connection terminal blocks) 13 6.6 Test for damage to conductors by clamping means (screw terminals) . 14 6.7 Test for firmness of clamping. 15 6.8 Test for firmness of attachment of a terminal block to its support . 16 6.9 Test for dielectric strength 17 6.10 Test for voltage drop across term

10、inal pairs 18 6.11 Temperature rise test. 20 6.12 Test for rated short-time withstand current 21 6.13 Test for resistance to aging 21 6.14 Sulphur dioxide test . 22 6.15 Test for resistance to impact 24 6.16 Test for resistance to heat (mouldings of materials other than rubber). 25 6.17 Test for res

11、istance to corrosion (ammonium chloride test) 25 6.18 Glow-wire test for resistance to burning 26 Figures 1-8 . 28-33 Appendix A Applicable standards. 34 Appendix B Determination of creepage distances . 35 Appendix C Determination of comparative tracking index 38 Appendix D Generation of the test at

12、mosphere by direct mixing of sulphur dioxide with air 40 Appendix E Quality verification of terminal blocks produced to the requirements laid down in this part of the specification. 41 Bibliography 44 Amdt 1 SANS 1433-1:2008 Edition 1.1 2 This page is intentionally left blank SANS 1433-1:2008 Editio

13、n 1.1 3 Electrical terminals and connectors Part 1: Terminal blocks having screw and screwless terminals 1 Scope 1.1 This part of the specification covers terminal blocks having screw type or screwless type clamping units for the connection of copper conductors having a rated area not exceeding 300

14、mm2for the screw type and not exceeding 35 mm2for the screwless type, and intended for use in installations having nominal a.c. voltages of r.m.s. value not exceeding 1 000 V and frequencies not exceeding 60 Hz, or nominal d.c. voltages not exceeding 1 500 V. 1.2 This part of the specification does

15、not cover requirements for flat push-on connectors1). NOTES a) This part of the specification refers primarily to terminal blocks and terminals for the connection of external conductors, but may be used as a guide for the requirements covering terminals forming an integral part of electrical equipme

16、nt or for internal connections of appliances. When such terminals or internal connections are so fitted, the relevant requirements, e.g. ignitability, dielectric strength, etc., of the standard applicable to the equipment to which the terminals are fitted shall take precedence. b) The standards refe

17、rred to in this part of the specification are listed in appendix A. c) A method for the determination of creepage distances is given in appendix B. d) A method for the determination of the comparative tracking index is given in appendix C. e) A method for the generation of a test atmosphere by direc

18、t mixing of sulphur dioxide with air is given in appendix D. f) Information regarding the verification of the quality of terminal blocks produced to this part of the specification, and the sampling plan to be used to assess compliance with this part of the specification of a lot of terminal blocks a

19、re given in appendix E. 1) See Part 2 of the specification. SANS 1433-1:2008 Edition 1.1 4 2 Definitions 2.1 For the purposes of this part of the specification the following definitions shall apply: acceptable acceptable to the authority administering this standard, or to the parties concluding the

20、purchase contract, as relevant Amdt 1 clamping unit those parts of a terminal that retain the conductor and exert and maintain the contact load between the terminal and the conductor rated area rated size the electrical (as distinct from the geometrical) cross-sectional area of a conductor rated cur

21、rent the maximum permissible continuous a.c. or d.c. current that a terminal can conduct, as assigned by the manufacturer rated voltage the maximum a.c. or d.c. voltage between a terminal and any adjacent metal part, as assigned to the terminal block by the manufacturer screwless terminal a terminal

22、 for the connection and, where so designed, the subsequent disconnection of a conductor, or for the interconnection of two or more conductors, the connection being made either directly or indirectly by means of springs and parts having suitable shapes such as wedges, cones and eccentrics screw termi

23、nal a terminal for the connection and subsequent disconnection of a conductor, or for the interconnection of two or more conductors, the connection being made either directly or indirectly by means of screws or nuts of any kind terminal that part of the conductive part of a terminal block to which o

24、ne or more than one electrical conductor can be connected terminal assembly two or more terminals fixed to the same conductive part terminal block an insulated part carrying or supporting one or more than one terminal assembly and intended to be fixed to a support T-rating a designation consisting o

25、f the letter “T“ followed by a number, the number being the maximum ambient temperature at which a terminal block may be used, as assigned by the manufacturer SANS 1433-1:2008 Edition 1.1 5 3 Constructional requirements 3.1 General 3.1.1 Workmanship Workmanship shall be in accordance with sound manu

26、facturing practice, and the components of a terminal block shall be so designed as not to constitute a danger to the user. 3.1.2 Materials Those parts of the clamping means, and screws and nuts where applicable, intended for carrying current, shall be of a) copper; or b) an alloy containing at least

27、 1) 58 %(m/m) copper for parts that are worked cold, and 2) 50 %(m/m) copper for other parts; or c) some other metal (with or without surface protection) that offers a resistance to corrosion equal or superior to that of copper, and has mechanical properties equal or superior to those of copper. Unl

28、ess suitably plated, metal parts in contact with rubber shall not be of copper or brass. Different metals in contact with each other shall be electrochemically compatible. Springs shall be of a phosphor-bronze, a stainless steel alloy conforming to the requirements for Alloy No. 30302 given in SAE J

29、405d, or of other acceptable material. NOTE Acceptable methods for the corrosion protection of metals include galvanizing, zinc impregnation, and plating with nickel, cadmium or zinc. Treatment with oil or grease is deemed to provide adequate protection for small parts. 3.2 Screws and nuts (screw te

30、rminals) 3.2.1 Screws and nuts used in terminals for the clamping of one or more conductors shall a) be of a metal that is neither soft nor liable to creep, such as zinc or aluminium; b) not serve to fix any other component, except that they may be used to retain the terminal in place or prevent it

31、from turning; c) be captive and not, when fully released, project above the mouldings of the terminal block for spring-loaded terminals; d) when designed to clamp directly onto the conductor(s) (see 3.3(e), have a diameter that is at least 0,75 times the diameter of the conductor hole, and be finish

32、ed off smoothly to minimize damage to the conductor(s); and e) when clamped to the conductor(s), have at least two full threads engaged. SANS 1433-1:2008 Edition 1.1 6 3.2.2 Only ISO metric threads shall be used and the fit of threads shall be such that slipping over of threads, undue movement and t

33、he working loose of parts is prevented when any conductor that is clamped in the terminal is manipulated. 3.3 Terminals a) A screw terminal shall be so designed as to accommodate a conductor having one of the following rated areas: 0,2; 0,5; 0,75; 1; 1,5; 2,5; 4; 6; 10; 16; 25; 35; 50; 70; 95; 120;

34、150; 185; 240 or 300 mm2. A screwless terminal shall be so designed as to accommodate a conductor having one of the rated areas 0,2 - 35 mm2(inclusive) given above. b) A terminal shall comply with all the relevant requirements of this part of the specification when used with a conductor two sizes sm

35、aller than that for which it is designed. c) A terminal shall be suitable for use with a conductor of one or more of the following types: solid, rigid stranded or flexible (see also 5.2.2(b). d) A terminal intended for use with a cable not having a lug or similar device, shall be so designed as to e

36、nable the cable to be connected to the terminal without special preparation of the conductor other than straightening the ends of the strands and twisting them. e) In the case of a rail-mounted terminal block, the screw of a screw terminal shall not clamp directly onto the conductor(s). f) A termina

37、l shall not become detached from its mounting means when the conductor(s) clamped in the terminal is/are manipulated as in normal use, or if the clamping screw or nut is tightened or loosened (see 4.5). g) A screw terminal shall be so designed that neither a solid conductor nor a strand of a strande

38、d conductor that has been inserted into the terminal can slip out while the clamping screw or nut is being tightened or loosened. h) The conductor entrance of a screwless terminal shall be so shaped as to guide a conductor into the correct position for clamping. i) The clamping unit of a terminal sh

39、all be so designed that a conductor is clamped with adequate contact load and without damage to the conductor. j) Unless a screwless terminal is designed for permanent connection, a clamped conductor shall be readily disconnected by an operation other than a pull on the conductor, and the means for

40、disconnection shall be such that the conductor can be disconnected by hand or with the aid of a general purpose tool. k) A screwless terminal intended for the interconnection of two or more conductors, either from the same side or from opposite sides of the terminal, shall be so designed that 1) onl

41、y one conductor at a time may be connected; and 2) each of the conductors that is connected to the terminal is securely clamped. l) In the case of a terminal designed for the connection of a conductor having rated area exceeding 0,75 mm2, 1) the surfaces between which the conductor is clamped shall

42、be of metal; and 2) the spring of a screwless terminal shall have been aged and shall not carry current. SANS 1433-1:2008 Edition 1.1 7 3.4 Terminal blocks a) A rail-mounted terminal block shall be so designed as to fit a rail that complies with the applicable requirements of IEC 60715. b) The live

43、parts of a protected connection terminal block shall not be accessible to touch when the terminal block is installed and fitted with conductors as in normal service (see 4.2). c) It shall be possible to replace any terminal block in an assembly of protected connection rail-mounted terminal blocks wi

44、thout having to dismantle any adjacent terminal block or loosen any fastening device at the rear of the mounting rail. d) The moulding of a terminal block shall not be subjected to stress caused by the clamping of conductors to the terminal. e) The contact pressure in any one terminal of a terminal

45、block shall not be affected by clamping adjustments made to any other terminal of the same terminal block. f) The isolating device of a terminal block shall be completely disconnected from at least one of a terminal pair when in the isolating position and shall give positive indication of isolation.

46、 g) An end barrier or a shield shall be provided to insulate the open end of an assembly of rail-mounted terminal blocks. h) When provided on a terminal block, a test socket shall be suitable for test plugs having a diameter of 2,5 mm or 4 mm. i) The creepage distances and clearances between unconne

47、cted conductive parts of a terminal block shall be at least the appropriate values given in columns 3 - 9 (inclusive) of table 1 for the relevant working voltage values given in columns 1 and 2. Table 1 Minimum creepage distances and clearances 1 2 3 4 5 6 7 8 9 Working voltage Creepage distance* mm

48、, min. Without ribs With ribs Comparative tracking index+d.c. V a.c. (r.m.s. value) V Clearance* mm, min. 100 - 400 401 - 750 more than 750100 - 400 401 - 750 more than 75030 30 0,3 0,4 0,35 0,3 0,35 0,3 0,3 60 60 0,4 0,5 0,45 0,4 0,45 0,4 0,4 125 125 0,5 1,0 0,75 0,5 0,75 0,5 0,5 250 250 1,0 1,5 1,

49、25 1,0 1,25 1,0 1,0 440 380 1,5 2,0 1,75 1,5 1,75 1,5 1,5 600 500 2,0 3,0 2,5 2,0 2,5 2,0 2,0 800 750 3,0 4,0 3,5 3,0 3,5 3,0 3,0 1 200 1 000 4,0 6,0 5,0 4,0 5,0 4,0 4,0 *These values are derived from tables B.1 and B.2 of appendix B for a type A environment. +See appendix C and IEC 60112. SANS 1433-1:2008 Edition 1.1 8 3.5 Ambient temperature rating a) Except as required in terms of (b) below, a terminal block shall have a T-rating of T40 and shall be suitable for operation indoors at ambient temperatures in the range -5 C to +40 C. b) For special duties (