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1、BRITISH STANDARD BS 7656:1993 Specification for Low-voltage pole-mounting fuses (cut-outs) 315 A rating Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 12:21:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7656:1993 This British Standard, having been prepared u
2、nder the direction of the Power Electrical Engineering Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 15 June 1993 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference PEL/10 Draft for comment
3、 92/21882 DC ISBN 0 580 21737 X Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Power Electrical Engineering Standards Policy Committee (PEL/-) to Technical Committee PEL/10, upon which the following bodies were represented: ASTA Certifi
4、cation Services Association of Control Manufacturers TACMA (BEAMA Ltd.) Association of Manufacturers Allied to the Electrical and Electronic Industry (BEAMA Ltd.) British Industrial Truck Association ERA Technology Ltd. Electrical Installation Equipment Manufacturers Association (BEAMA Ltd.) Electri
5、city Association Electronic Components Industry Federation Engineering Equipment and Materials Users Association GAMBICA (BEAMA Ltd.) Health and Safety Executive Institution of Electrical Engineers Amendments issued since publication Amd. No.DateComments Licensed Copy: London South Bank University,
6、London South Bank University, Fri Dec 08 12:21:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7656:1993 BSI 09-1999i Contents Page Committees responsibleInside front cover Forewordii 1General1 1.1Scope1 1.2Vacant1 1.3References1 1.3.1Normative references1 1.3.2Informative references1 2Definitions1
7、 3Vacant2 4Characteristics2 4.1General2 4.2Type of equipment2 4.3Rated and limiting values for the main circuits2 5Product information2 5.1Nature of information2 5.2Marking2 5.3Instructions for installation, operation and maintenance2 6Normal service and mounting conditions2 6.1Normal service condit
8、ions2 6.1.1Ambient air temperature2 6.1.3.2Pollution degree3 6.2Vacant3 6.3Mounting3 7Constructional and performance requirements3 7.1Constructional requirements3 7.1.1Materials3 7.1.2Current carrying parts and their connections3 7.1.2.101 Fuse-carriers3 7.1.2.102 Fuse-bases3 7.1.3Clearances and cre
9、epage distances3 7.1.4Vacant3 7.1.5Vacant3 7.1.6Vacant3 7.1.7Terminals3 7.1.7.1Constructional requirements3 7.1.8Vacant3 7.1.9Vacant3 7.1.10Enclosures for equipment3 7.1.10.1Design3 7.1.11Degrees of protection of enclosed equipment4 7.2Performance requirements4 7.2.1Vacant4 7.2.2Temperature-rise4 7.
10、2.2.101 Long term contact stability4 7.2.3Dielectric properties4 7.2.4Vacant4 7.2.5Vacant4 Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 12:21:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7656:1993 ii BSI 09-1999 Page 7.2.6Vacant4 7.2.7Performance on overl
11、oad and short circuit4 8Tests4 8.1Kinds of tests4 8.1.1General4 8.1.2Type tests4 8.1.3Routine tests4 8.2Conformity with constructional requirements4 8.2.1Materials4 8.2.1.101 Flammability test4 8.2.1.102 Resistance to tracking5 8.2.2Equipment5 8.2.2.101 Impact test5 8.2.2.102 Thumbscrew torque withs
12、tand5 8.2.3Enclosures for equipment5 8.2.3.101 Degree of protection test5 8.2.4Vacant5 8.3Performance5 8.3.1Test sequences5 8.3.2General test conditions5 8.3.2.1General requirements5 8.3.2.2Test quantities7 8.3.3Performance under no load, normal load and overload conditions7 8.3.3.1Vacant7 8.3.3.2Va
13、cant7 8.3.3.3Temperature-rise7 8.3.3.4Dielectric properties9 8.3.4Performance under short-circuit conditions10 Figure 101 Apparatus for impact test6 Figure 102 Arrangement of test circuit8 Table 101 Type tests7 Table 102 Maximum temperature-rise at rated current8 Table 103 Values for overload test c
14、urrent9 List of referencesInside back cover Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 12:21:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7656:1993 BSI 09-1999iii Foreword This British Standard has been prepared under the direction of the Power Electric
15、al Engineering Standards Policy Committee. It is based on the Electricity Association Technical Specification 12-20, and has been updated to reflect current practice and standards. This standard was originally submitted to CENELEC under the Vilamoura Procedure, but in the absence of interest by othe
16、r national committees, it was derogated to the UK for publication as a national standard. This standard is to be read in conjunction with BS EN 60947-1:1992 and therefore for ease of cross-reference it has clause numbering following the style of BS EN 60947-1. Subclauses, tables or figures which are
17、 additional to those in BS EN 60947-1 are numbered starting from Figure 101. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself conf
18、er immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated
19、 in the amendment table on the inside front cover. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 12:21:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 12:21:38 GMT+00:
20、00 2006, Uncontrolled Copy, (c) BSI BS 7656:1993 BSI 09-19991 1 General 1.1 Scope This standard specifies the requirements for single-pole fuses (cut-outs) of 315 A rating which are mounted on poles for low-voltage network protection, sectioning or sub-fusing. The fuses (cut-outs) may be mounted on
21、a high-voltage/low-voltage transformer pole where the high-voltage equipment earth is led down the pole. They are for use on a single phase, or one phase of a three phase low-voltage public electricity supply system with a maximum voltage up to 440 V a.c. and at a frequency of 50 Hz, the neutral bei
22、ng effectively earthed. The provisions of the general rules dealt with in BS EN 60947-1 are applicable to this standard where specifically called for. NOTEClauses and subclauses, tables, figures and annexes of the general rules thus applicable are identified by reference to BS EN 60947-1 for example
23、 1.2.3 of BS EN 60947-1, Table IV of BS EN 60947-1, or Appendix A of BS EN 60947-1. 1.2 Vacant 1.3 References 1.3.1 Normative references This British Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate place
24、s in the text and the publications are listed on the inside back cover. For a dated reference, only the edition cited applies; any subsequent amendments to or revisions of the publication apply to this British Standard only when incorporated in the reference by amendment or revision. For undated ref
25、erences, the latest edition of the publication applies together with any amendments. 1.3.2 Informative references This British Standard refers to other publications that provide information or guidance. Editions of these publications current at the time of issue of this standard are listed on the in
26、side back cover, but reference should be made to the latest editions. 2 Definitions For the purposes of this British Standard, the definitions given in BS EN 60947-1:1992 apply, together with the following which have been reproduced from BS 88-1:1988, BS 3456-201:1990 and BS 4727-2:Group 06:1985. 2.
27、1 fuse-carrier (206 8013 of BS 4727-2.06) the moveable part of a fuse designed to carry a fuse-link. 2.2 fuse-base (fuse-mount) (2.1.2 of BS 88-1) the fixed part of a fuse provided with terminals for connection to the system. The fuse-base comprises all the parts necessary for insulation 2.3 fuse-ho
28、lder (2.1.6 of BS 88-1) the combination of a fuse-base with its fuse-carrier 2.4 fuse-link (206 8009 of BS 4727-2.06) the part of a fuse (including the fuse-elements) intended to be replaced after the fuse has operated 2.5 fuse (cut-out) (206 8001 of BS 4727-2.06) a device that, by fusion of one or
29、more of its specifically designed and proportioned components, opens the circuit in which it is inserted by breaking the current when this exceeds a given value for a sufficient time. The fuse comprises all the parts that form the complete device 2.6 fuse-link contact (2.1.8 of BS 88-1) a conducting
30、 part of a fuse-link designed to engage with a fuse-base contact or with a fuse-carrier contact 2.7 fuse-base contact (fuse-mount contact) (2.1.3 of BS 88-1) a conducting part of a fuse-base connected to a terminal designed to engage with a fuse-carrier contact or with a fuse-link contact 2.8 basic
31、insulation (2.2.12 of BS 3456-201) the insulation applied to live parts to provide basic protection against electric shock 2.9 supplementary insulation (2.2.13 of BS 3456-201) an independent insulation applied in addition to the basic insulation in order to ensure protection against electric shock i
32、n the event of a failure of the basic insulation 2.10 double insulation (2.2.14 of BS 3456-201) insulation comprising both basic insulation and supplementary insulation Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 12:21:38 GMT+00:00 2006, Uncontrolled Copy, (
33、c) BSI BS 7656:1993 2 BSI 09-1999 2.11 reinforced insulation (2.2.15 of BS 3456-201) a single insulation system applied to live parts, which provides a degree of protection against electric shock equivalent to double insulation under the conditions specified in this standard NOTEThe term “insulation
34、 system” does not imply that the insulation must be one homogeneous piece. It may comprise several layers which cannot be tested singly as supplementary or basic insulation. 3 Vacant 4 Characteristics Clause 4 of BS EN 60947-1 applies only in relation to the following characteristics, and with delet
35、ions and additions to the subclauses as indicated: 4.1 General Subclause 4.1 of BS EN 60947-1 applies. 4.2 Type of equipment Subclause 4.2 of BS EN 60947-1 applies. 4.3 Rated and limiting values for the main circuits Subclause 4.3 of BS EN 60947-1 applies modified as follows: Deletions: 4.3.2.1 Conv
36、entional free air thermal current (Ith) 4.3.2.2 Conventional enclosed thermal current (Ithe) 4.3.4 Rated duties 4.3.5 Normal load and overload characteristics 4.3.6 Short-circuit characteristics Additions: 4.3.2.4.101 Fuses A fuse shall be capable of carrying current up to its rated uninterrupted cu
37、rrent of 315 A, and the currents associated with the operation under fault conditions of any fuse-link which the fuses are designed to accommodate. 4.3.1.1 Rated operational voltage (Ue) Fuses shall operate on low-voltage public electricity supply systems with a maximum voltage up to 440 V a.c. 5 Pr
38、oduct information 5.1 Nature of information Subclause 5.1 of BS EN 60947-1 applies with the following modification. Characteristics: Delete the text and substitute the following: rated operational voltage (Ue) 250 V a.c. (see 4.3.1.1); rated uninterrupted current (Iu) (see 4.3.1.1); the value of the
39、 rated frequency 50 Hz; rated insulation voltage (Ui) 440 V a.c. r.m.s.; rated impulse withstand voltage (Uimp) 3.75 kV a.c. r.m.s.; rated short-time withstand current (Icu) 18 kA a.c. r.m.s, together with its duration 0.02 s (see 7.2.7); IP code (see Appendix C of BS EN 60947-1 and 7.1.11); polluti
40、on degree 4. 5.2 Marking The fuse-carrier shall be clearly and permanently marked according to BS 88-1 and shall be identified with its fuse-base. 5.3 Instructions for installation, operation and maintenance Subclause 5.3 of BS EN 60947-1 applies. 6 Normal service and mounting conditions 6.1 Normal
41、service conditions Subclause 6.1 of BS EN 60947-1 applies with the following modifications and additions: 6.1.1 Ambient air temperature Modification: The requirements for the lower limit of the ambient air temperatures are to be as follows: The lower limit of the ambient air temperature shall be 25
42、C as required by BS 5486-1 for outdoor installed low-voltage switchgear and controlgear assemblies. Rated operational voltage(Ue); Rated insulation voltage(Ui); Rated impulse withstand voltage(Uimp); Rated uninterrupted current(Iu); Rated frequency; Rated short-time withstand current (Icw). Licensed
43、 Copy: London South Bank University, London South Bank University, Fri Dec 08 12:21:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7656:1993 BSI 09-19993 6.1.3.2 Pollution degree Addition: The fuses shall be suitable for operating in a pollution degree 4 environment which is subject to solar radia
44、tion. 6.2 Vacant 6.3 Mounting The fuse-holder shall be capable of being fixed to a flat surface or curved convex surfaces with minimum radius of 90 mm. When mounted for multiphase application at 380 mm vertical spacing between fixing points, there shall be sufficient access for safe insertion and re
45、moval of fuse-carriers. Preferably, a single point fixing arrangement shall be provided which is sufficiently secure to prevent movement during cable installation and fuse-carrier removal and insertion. 7 Constructional and performance requirements 7.1 Constructional requirements 7.1.1 Materials Sub
46、clause 7.1.1 of BS EN 60947-1 applies with the following addition. The insulating integral enclosure shall be in accordance with BS 3456-201 for Class II appliances utilizing reinforced insulation. It shall be constructed from non-hygrosopic material conforming to BS 771, BS 1322 or BS 5734. These m
47、aterials shall also have fire retardant properties which shall be verified by tests given in 8.2.1.101 and shall have a comparative tracking index (CTI), in accordance with BS 5901, of not less than 500. 7.1.2 Current carrying parts and their connections Subclause 7.1.2 of BS EN 60947-1 applies with
48、 the following additions. 7.1.2.101 Fuse-carriers Fuse-carriers shall have a rated uninterrupted current of 315 A and shall fit the fuse-bases to 7.1.2.102. It shall be possible for the fuse-carrier with fuse-link to be inserted by hinge action pivoted on either of the fuse-base contacts and be with
49、drawn by snatch action. If the fuse-carrier is designed for hand operation, the handle shall be of through-grip construction. The fuse-carrier shall be suitable for accepting fuse-links, with fixing centres at 82 mm, which conform to the general requirements of BS 88-1 and BS 88-5. The fuse-carrier shall afford a secure connection for the fuse-link to the fuse-base contacts. If this is provided by means of wedge connections and a thumbscrew tightening mechanism, conformity to 8.2.2.102 and 8.3.3.2.2 is required. 7.1.2.102 Fuse-bases Fuse-bases s
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