Disclosure to Promote the Right To Information

Transcription

1 इ टरन ट म नक Disclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public. ज न1 क अ+धक र, ज 1 क अ+धक र Mazdoor Kisan Shakti Sangathan The Right to Information, The Right to Live प0र 1 क छ ड न' 5 तरफ Jawaharlal Nehru Step Out From the Old to the New IS (1989): Brushholders for slip rings group RType RA [ETD 15: Rotating Machinery]! न $ एक न' भ रत क +नमण Satyanarayan Gangaram Pitroda Invent a New India Using Knowledge! न एक ऐस खज न > ज कभ च0र य नहB ज सकत ह ह Bhartṛhari Nītiśatakam Knowledge is such a treasure which cannot be stolen

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4 IS : 1989 Indian Standard BRUSHHOLDERSFORSLIPRINGSGROUPR, TYPE RASPECIFICATION U DC * l tlureau OF INDIAN STANDARDS MANAK JQfAVAN, ) HAffADIJlC SlfAIf %AFAR MARC NEW 1~ILITI I IOOO!! rlugusl 1!)!)O Price Group 4

5 Rotating Machinery Sectional Committee, ETDC 15 FOREWORD This Indian Standard was adopted by the Bureau of Indian Standards on 30 January 1989, after the draft finalized by the Rotating Machinery Sectional Committee had been approved by the Electrotechnical Division Council. This standard defines radial brushholders for slip rings to be used on medium size asynchronous industrial machines for general applications. This standard has been prepared in line with IEC Report 778 ( 198I ) Brushholders for slip rings group R Type KA, published by the International Electrotechnical Commission ( IEC ).

6 Indian Standard IS t 1989 BRUSHyHOLDERS FOR SLIP RINGS GROUP R, TYPE RA SPECIFICATION I SCOPE SECTION 1.1 This standard for brushholders is applicable to medium size asychronous industrial machines of conventional construction for general applications, having shaft heights between 160 and 400 mm in the recommended range ( in millimetres ): REFERENCES 2.1 The following Indian Standards have been referred to in this standard: IS.No. Title IS 3003 Specification for carbon ( Part 1 ) : 1977 brushes for electrical machines: Part 1 Definitions and nomenclature (Jirst revision ) IS 3003 Specification for carbon ( Part 3 ) : 1978 brushes for electrical machines: Part 1 Dimensions and requirements 3 TERMINOLOGY 3.1 The general terms on carbon brushes defined in IS 3003 ( Part 1 ) : 1977 shall apply. 1 GENERAL 3.2 These brushholders are distinguished by t ( tangential dimensions of the brush ) being greater than a ( axial dimension of the brush ) 3.3 These brushholders will be known as Brushholders, Type RA. 4 UTILIZATION LIMITS 4.1 The standard Type RA brushholders are intended for use in a limited number of slip ring sizes for each motor shaft height. 4.2 The slip ring diameters which can be used for each shaft height are given in Table 1 ( figures which are underlined indicate the preferred values ). 4.3 Fixing Type RA brushholders are intended exclusively for fixing by clamping on a single round bar Type RA brushholders are intended to be located 2 mm from the slip ring at its nominal diameter. 4.4 Provision for taking up slip ring wear is not mandatory for the design of Type RA brushholders.

7 IS : 1989 Table 1 SlipRing Sizes ( Clause 4.2 ) ameter (mm) I ~~ F Shaft Height ( mm ) 280 I j 400 l I, xl,x/ 125 _ 140 _._ 160. _ _.. c_ A_ 250 ~ i, SECTION 2 GENERAL CHARACTERISTICS 5 NUMBER AND ARRANGEMENT OF THE In this form, the brushholder is known as brush BRUSHES holder Type RAB. 5.1 Slip rings of industrial asychronous machines would normally be provided with one brushholder having two identical radial brushes per ring(2twith2 x lbox). 5.2 The corresponding brushholders Type RA are, therefore, normally provided for two radial brushes. In this form, the brushholder is known as c brushholder Type RAA. 6 NOMINAL CONTACT SURFACE OF THE BRUSH(ES) 6.1 The nominal contact surface in each brushholder Type RA is represented by the total contact surface of all the brushes in the brushholder. 6.2 The range of nominal contact surface ( in square millimetres ) follows the following progression 5.3 However, within stated overall dimensions and with the same characteristics, the brushholders Type RA can be made with one single brush box, for one brush ( T with 1 box ). Brushholder Type RAA : 200, 250, 315, , 630, 800, , 1 600,

8 IS : 1989 Brushholders Type RAB : 100, 125, 160, 200 ponds a limited number of brushholders defined 250, 315, 400, 500 by the nominal contact surfaces of the brush(es). 630, 800, CHOICE OF BRUSHHOLDERS 7.2 The acceptable combinations are given in Table 2 ( Figures which are underlined indicate 7.1 For each diameter of slip ring, there corres the preferred values ). Table 2 Selection of BrushHolders ( Clause 7.2 ) Nominal Contact Surface of the Brush(es) per BrushHolder TYPO RAA ( mma _ x I x _ x I x 630 I. I.; _ TYPO RAB (mmz) _.. Diameter of SlipRings (mm) _ I l.. _ E I ~ _.. _.. 7 _.... /_ _.., 1. _ l 3

9 IS : SECTION t x u OF THE BRUSHES Y RADIAL DIMENSION OF THE BRUSHES 9.1 Brushholders of Type RAA or RAB shall 8.1 Corresponding to each total nominal contact always allow the use of brushes having the prefersurface of the brush(es) of Type RAA or RAB red range of r given in IS 3003 ( Part 3 ) : brushholder, a single t x a section of the indivi NOTE For RAA and RAB brushholders, for sections t x a = 32 mm x 12 5 mm and 40 mm x 16 mm, an dual brush is given in Table 3. exception has been made in adopting r = 40 mm. Nominal Table 3 Section t x a of Brushes ( Clause 8.1 ) Contact Surface of the Brush(es) per BrushHolder txa ( per Brush ) Type RAA Type RAB (mms) ( mma 1 (1) (2) (mm) (3) x 8 L x x x x x x x O x x CONSTRUCTIONAL DIMENSIONS SECTION 3 DIMENSIONAL CHARACTERISTICS MAIMUM BRUSH 10.1 The dimensions of Types RAA and RAB brushholder are shown in Fig. 1 and 2 and their values are given in Table These values define for each brushholder, in conjunction with a given slip ring, the main constructional dimensions and the limiting envelopes in terms of the preferred I dimension of the brush suited to the particular brushholders ( see Note below 9.1 ) The symbols, definitions and the values of the dimensions are given in Table 4. MUM WORKING Fro. 1 DIMENSIONS OF TYPE RAA BRUSHHOLDERS 4

10 IS I 1989 Table 4 Dimensional Characteristics ( Clauses 10.1, 10.2and 11.4 ) Symbols Definitions Values I d Nominal diameter of the hole for the spindle in the brushholder 0 5 r H Distance from the peripheral surface of the slipring to the radial axis of the brushholder support spindle hole 0 8 r Rlmax R2max Llmax L2max L3max L4.. Maximum radial envelope around the slipring for the brushholder in working position Maximum radial envelope around the slipring for the brushholder in the brush changing position AZmax Maximum axial envelope of the brushholder 0 63 r f2 mm Maximum linear envelope of the brushholder on both sides ( RAA ) or on single side ( RAB ) of the radial axis of the brushholder support spindle hole for the brushholder in working position Maximum linear envelope of the brushholder on both sides ( RAA ) or on single side ( RAB ) of the radial axis of the brushholder support spindle hole for the brushholder in the brush changing position Maximum linear position of the most distant part of the brush with the preferred r dimension, from the radial axis of the brushholder support spindle hole Maximum linear envelope of brushholder Type RAB from the radial axis ofthe bore for the brushholder spindle hole on the side opposite to that of Llmax and Umax emax Maximum angular envelope of the brushholder on each side ( RAA ) or See Table 5 on single side ( RAB ) of the radial axis of the brushholder support spindle hole _ Almax Umax Maximum axial dimension of the brushholder on the brushholder support spindle The usable length ( maximum wearing length ) of the brush related to the minimum dimension rm NOTE Standardized brushholders cannot differ according to the variations of rm; they should, therefore, allow the use of brushes having the greatest usable length Umax Ulmin Distance from the bottom of the brush box to the lowest point where the 0.35 r 2 mm nominal load ( pressure ) applied to the brush of minimum dimensior I rm is guaranteed u2 u3 NOTE It is not recommerded that the pressure on the brush shoulc be arrested completely when the brush is fully worn Safety factor or the supplementary distance over which an acceptable load ( pressure ) is still maintained on the~brush Distance from the bottom of the brush box to the lowest point where at acceptable load ( pressure ) is applied by the pressure mechanism 5 I ~ 2r 2.2 r 3r 3.5 r 0 55 r 0.65 r 0 05 r 0 30 r 2 mm

11 Table 4 ( concluded ) Symbols Definitions Values u4 Zone of travel ofthe pressure mechanism where no control is provided over the pressure NOTE Whatever the value of U4 provided by the brushholder manufacturer, the pressure mechanism shall not project beyond the bottom of the brush box r Brush Nominal dimensions of the brush connection screw for scouring the connection brush termination screw NOTE Other necessary screws ( for example, for securing the clamps ) should be of a size different to the brush termination screw See Table 5 Main Nominal dimensions of the main connection screw for securing the See Table 5 connection connection to the terminal post screw NOTEThe location of screws is not given on Fig. 1. At the discretion of the brushholder constructor, they should be placed within the maximum envelope given for the brushholder in its working position NOTE For the other dimensions, refer to Type RAA brushholder. Fro. 2 DIMENSIONS OF TYPE RAB BRUSHIKOLDERS SECTION 4 CHARACTERISTICS OF THE FINISHED BRUSHHOLDERS 11 PRESSURE ON THE BRUSH 11.1 The specific pressure applied to the brush shall be set by the brushholder manufacturer to one of the values below ( expressed in kilopascals ) in accordance with the requirements of the purchaser. The preferred value is underlined. Specific pressure (kpa) : 15; 17.5; 20; 22.5; Brushholders with spring pressure capable of being adjusted by the user are not recommended The setting of the spring pressure by the brushholder manufacturer to values which are intermediate to those shown in 11.1 is not allowed The spring pressure as adjusted by the brushholder manufacturer shall maintain the nominal value selected to &lo percent over the wearing length designated by U ( see Table 4 and Fig. 1 ) It is desirable that the force measured in the worn brush position should be equal to or less than the force measured in the position of the new brush of the preferred dimension r. 12 MARKING 12.1 The following indications shall be marked on Type RAA and RAB brushholders by the brushholder manufacturer. 6

12 IS : Metric Dimensions The 0 sign shall be shown clearly on the brushholder Pressure or Force on Brush The marking applied by the brushholder manufacturer will differ according to the following two cases: First Case Spring pressure systems forming an integral part of the brushholder construction. A colour marking shall be applied to the spring. The conventional colour code is as follows: NOTE lf, for specific reasons, the spring pressure is adjusted to less than 15 kpa or greater than 25 kpa, the marking colour shall be yellow regardless of the special value demanded by the user. Second Case Spring pressure systems which are removable~are, not permanently attached to the brushholder. The total force applied to the brush shall be visibly marked in newtons on the spring system. NOTE Zrude Mark The use of a trade mark is optional and its location is left to the discretion of the brushholder manufacturer. SECTION 5 ADDITIONAL INFORMATION 13. DATA NECESSARY FOR THE DEFINI TION OF A BRUSHHOLDER TYPE RA a m... D =..., mm mm 13.1 In order to define a brushholder Type RA ( for example, in preparing a specification/documents ), in all cases, it is necessary to specify: ISS Type RAA or RAB brushholder according to this standard The values t, a and D t= mm 13.4 The pressure on the brush, if different from the preferred pressure If necessary, any special conditions of use ( for example, corrosive atmosphere, etc ). 14 DIMENSIONAL TOLERANCES TESTS 14.1 The determination of tolerances and tests for checking and inspection are not covered at present and will be subject of agreement between the manufacturer and the user,

13 I Standard Mark The use of the Standard Mark is governed by the provisions of the Bureau of Indian Standards Act, 1986 and the Rules and Regulations made thereunder. The Standard Mark on products covered by an Indian Standard conveys the assurance that they have been produced to comply with the requirements of that standard under a well defined system of inspection, testing and quality control which is devised and supervised by BIS and operated by the producer. Standard marked products are also continuously checked by BIS for conformity to that standard as a further safeguard. Details of conditions under which a licence for the use of~the Standard Mark may be granted to manufacturers or producers may be obtained from the Bureau of Indian Standards. ~ I

14 Bureau of Indian Standards. BIS is a statutory institution established under the Bureau of Indian Standards Act, 1986 to harmonious development of the activities of standardization, marking and quality certification and attending to connected matters in the country. Copyright promote of goods BIS has the copyright of all its publications. No part of these publications may be reproduced in any form without the prior permission in writing of BIS. This does not preclude the free use, in the course of implementing the standard, of necessary details, such as symbols and sizes, type or grade designations. Enquiries relating to copyright be addressed to the Director ( Publications ), BIS. Revision of Indian Standards Indian Standards are reviewed periodically and revised, when necessary and amendments, if any, are issued from time to time. Users of Indian Standards should ascertain that they are in possession of the latest amendments or edition. Comments on this Indian Standard may be sent to BIS giving the following reference: Dot : No. ETDC 15 ( ) Amendments Issued Since Publication Amend No. Date of Issue Text Affected Headquarters : BUREAU OF INDIAN STANDARDS Manak Bhavan, 9 Bahadur Shah Zafar Marg, New Delhi Telephones : , Telegrams : Manaksanst ha (Common to all Offices ) Regional Offices : Telephone Central : Manak Bhavan, 9 Bahadur Shah Zafar Marg NEW DELHI Eastern : 1 14 C. I. T. Scheme VII M, V. I. P. Road, Maniktola d ALCUTTA ~Northern : SC , Sector 35C, CHANDIGARH Southern : C. I. T. Campus, IV Cross Rnad, MADRAS Western : Manakalaya, E9 MIDC, Marol, Andheri ( East ) BOMBAY Branches : AHMADABAD. BANGALORE. BHOPAL. BHUBANESWAR. COIMBATORE. FARIDABAD. GHAZIABAD. GUWAHATI. HYDERABAD. JAIPUR. KANPUR. PATNA. THIRUVANANTHAPURAM.,. Printed at New India Printing Press. Khuria. India