SPECIFICATION FOR LOW-VOLTAGE SWITCHGEAR AN,D …

1 IS 13947 ( Part 3 ) : 1993 IEC Pub 947-3 ( 1990 ) [ Superseding IS 4064 ( Parts 1 and 2 ) ] SPECIFICATION FOR LOW-VOLTAGE SWITCHGEAR AN,D controlgear PART 3 SWITCHES, DISCONNdCTORS, SWIS CH disconnectors AND FUSE COMBINATION UNITS * k ( Second Reprint MAY 1997 ) UDC 621 316 542 064 241 : 621 316 923 s @I BIS 1993 AJREI~:~ 0F INDIAN STANDARDS MANAK BH;PVAN 9 BAYADUR SHAH ZAFAR MARG NEW DELHI 110002 June 1993 Price Grou p 14 - IS 13947 ( Part 3 ) : 1993 IEC Pub 947-3 ( 1990) Indian Standard SPECIFICATION FOR LOW-VOLTAGE SWITCHGEAR AND controlgear PART 3 SWITCHES, disconnectors . SWITCH disconnectors AND FUSE COMBINATION UNITS NATIONAL FOREWORD This Indian Standard ( Part 3 ) which is identical with IEC Pub 947-3 ( 1990 ) is one in the series of standards on LV SWITCHGEAR equipment covering requirements for switches and their family of items together with fuse combination units.

2 This standard shall be read in conjunctron with Part 1 of this standard covering general requirements. The text of the IEC Standard has been considered and approved by ET 07, Low voltage Switch- gear and controlgear Sectional Committee of BIS, as suitable for publication as Indian Standard, superseding the contents of IS 4064 ( Parts 1 and 2 ). With reference to the definitions contained in and ,>f this standard, it is stated that the terms Switchfuse and Fuseswitch have been defined in these clauses due ta these terms being in vogue though however no distinction is being made in so far as requirements and tests for compliance are concerned. CROSS REFERENCE In this Indian Standard the following International Standards are referred to.

3 Read in their respective place the following: International Standard ( IEC ) Indian Standard 50 (441) (1984) IS 1885 ( Part 17 ) 417 ( 1973 ) Nil 617-7 ( 1983 ) IS 12032 ( Part 7 ) In the case of IEC Pub 417, noting that Indian Standard identical to this is under print, the Technical Committee responsible for this standard has decided that it is acceptable for use in conjunction with this standard. As in the Original Standard, this Page is Intentionally Left BlankIS 13947 ( Part 3 ) : 1993 IEC Pub 947 - 3 ( 1990 ) CONTENTS Page Clause 1. General .. Scope .. Object .. 2. Definitions .. & .$ 3. Classification .. , , 4. Characteristics .. Summary of characteristics.

4 Type of equipment .. Rated and limiting values for the main circuit .. Utilization category .. Control circuits .. Auxiliary circuits .. Relays and releases .. Vacant .. Switching overvoltages .. 5. Product information .. 14 Nature of information .. 14 Marking .. 14 Instructions for installation, operation and maintenance .. 15 6. Normal service, mounting, and transport condi. 7. Constructional and performance requirements Constructional requirements .. tions .. Performance requirements .. ).. Operating conditions .., .. Temperature-rise .. Dielectr+ic properties .. ,4 Ability, to make and break under no-load, normal load and overload conditions.

5 Abilit$: to make, break or withstand short-circuit currenlts .. Switching overvoltages .. ; 7 Additional performance requirements for equipment suitable for isolation .. 5 5 6 6 9 9 1: 10 12 :z 14 i4 14 15 16 16 17 17 17 17 17 20 21 21 3 IS 13947 (Part 3 ) : 1993 IEC Pub 947 - 3 i 1990 ) Clause 8. Tests .. Kinds of tests .. Type tests for constructional requirements .. Type tests for performance .. Test sequences .. General test conditions .. Test sequence I: General performance character- istics .. Test sequence I I i Operational performance capability .. Test sequence Ill: Short-circuit performance capability .. Test sequence IV: Conditional short-circuit current.

6 Routine tests .. Special tests .. :+.. :f .. j Y,, APPENDIX A - Equipment for direct switching of a single motor .. APPENDIX B - Clearances and creepage distances .. APPENDIX C - Items subject to agreement between manufacturer and user .. TABLES I. II. III. IV. V. VI. VII. VIII IX. X. Xl. XII. Summary of equipment definitions .. Utilization categories .. Verification of rated making and breaking capacities - Conditions for making and breaking corresponding to the various utilization categories .. Verification of operational performance - Number of operating cycles corresponding to the rated operational current .. Test circuit parameters for Table IV .. Actuator test force.

7 List of type tests applicable to a given equipment .. Overall scheme of test sequences .. Test sequence I : General performance characteristics .. Dielectric tegt voltage corresponding to the rated insulation voltage .. Test seque,qce I I : Operational perfor mance capability .. , .. Test sequeice 1 I I : Short-circuit performance capability .. XIII. Test sequence IV: Conditional short-circuit current .. , .. 41 Page 21 21 21 25 25 25 26 , 32 35 40 42 43, 44 52 54 8 13 18 19 20 22 24 25 27 29 33 36 4 IS 13947 (Part 3) : 1993 IEC Pub 947 - 3 ( 1990 ) General The provisions of the general rules dealt with in Part 1 (IEC Pu- blication 947-l) are applicable to this standard, where specifically called for.

8 Clauses and sub-clauses, tables, figures and appendices of the general rules thus applicable are identified by reference to Part 1, , Sub-clause of Part 1, Table IV of Part 1, or Appendix A of Part 1. Il. 1 Scope 4 3 . This standard applies to swi&hes, disconnktors, switch-disconnec- tors and fuse-combination units to be used in distribution circuits and motor circuits of which the rated voltage does not exceed 1 000 V or 1 500 V The manufacturer shall specify the type, ratings and characteristics according to the relevant standard of any incorporated fuses. This standard does not apply to equipment coming within the scope of IEC Publications 947-2, 947-4-l and 947-5-1; however, when switches and fuse-combination units coming into the scope of this standard are normally used to start, accelerate and/or stop an indi- vidual motor they shall also comply with the additional requirements given in Appendix A.

9 This standard does not include the additional requirements necessary for electrical apparatus for explosive gas atmospheres. No tcs Depending on its design, a switch (or disconnector) can be referred to as "a rotary switch (disconnector)", "cam- operated switch (disconnector)", "knife--switch (disconnec- for)", etc. If they are not manually operated, switches and discon- nectors may have to comply with additional requirements. In this standard, the word "switch" also applies to the apparatus'referred to in French as "commutateurs", intended ! to modify the connections between several circuits and inter to substitute a part of a circuit for another. i In general, throughout this standard switches, disconnec- tors, switch- disconnectors and fuse-combination units will.

10 Be referred to as "equipment". IS 13947 (Part 3 ) : 1993 IEC Pub 947 - 3 ( 1990 ) Object The object of this standard is to state: a) the characteristics of the equipment; 6) the conditions with which the equipment shall comply with refer- ence to: 1) operation and behaviour in normal service; 2) operation and behaviour in case of specified abnormal conditions, short circuit; 3) dielectric properties; c) the tests for confirming that these conditions have been met and the methods to be adopted for these tests; d) the information to be marked on the equipment or made available by the manufactur4r, inphe catalogue. * I,.., 2. Definitions For the majority of the definitions required in connection with this standard, see Clause 2 of Part 1.