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1、BRITISH STANDARD BS 4846:1972 Specification for Resistors for traction purposes UDC 621.316.8:621.33:629.1 83 Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 01:53:09 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4846:1972 This British Standard, having been approved by the Electrical Industry
2、 Standards Committee, was published under the authority of the Executive Board on 27 October 1972 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference ELE/44/1 Draft for comment 70325489 ISBN 0 580 07387 4 Co-operating organizations The Electrical Industr
3、y Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Associated Offices Technical CommitteeElectrical Contractors Association of Scotland Association of Co
4、nsulting Engineers*Electrical Research Association Association of Manufacturers of DomesticElectricity Council, the Central Electricity Electrical AppliancesGenerating Board and the Area Association of Mining Electrical andBoards in England and Wales* Mechanical EngineersElectronic Engineering Assoc
5、iation Association of Public Passenger TransportEngineering Equipment Users Association Operators*Institution of Electrical and Electronics Association of Supervisory and ExecutiveTechnician Engineers EngineersInstitution of Electrical Engineers* British Electrical and Allied ManufacturersLighting I
6、ndustry Federation Limited Association*Ministry of Aviation Supply British Radio Equipment ManufacturersMinistry of Defence Association*Ministry of Defence, Army Department British Railways Board*Ministry of Defence, Navy Department British Steel CorporationNational Inspection Council for Electrical
7、 Crown Agents for Oversea Governments andInstallation Contracting AdministrationsNational Physical Laboratory (Department of Department of Employment*Trade and Industry) Department of the Environment*Oil Companies Materials Association Department of Trade and IndustryPost Office Electric Cable Maker
8、s Confederation*South of Scotland Electricity Board Electrical Contractors Association (Incorporated)* The Government departments and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted w
9、ith the preparation of this British Standard: London Transport ExecutiveRailway Industry Association of Great Britain Public Road Transport Association Amendments issued since publication Amd. No.Date of issueComments Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 01:53:09 GMT+00:00 2006, Un
10、controlled Copy, (c) BSI BS 4846:1972 BSI 09-1999i Contents Page Co-operating organizationsInside front cover Forewordii 1General1 1.1Scope1 1.2Definitions1 1.3Categories of tests1 2Conditions to be satisfied by resistors2 2.1Resistance values2 2.2Temperature rises2 2.3Short-circuit withstand2 2.4Vi
11、bration and shock withstand2 2.5Protection against corrosion2 2.6Performance in rain and snow2 3Tests2 3.1List of tests2 3.2Check on characteristics of resistor material (type test)3 3.3Check on rated resistance (type and routine tests)3 3.4Temperature-rise tests (type tests)3 3.5Tests for withstand
12、ing vibration and shock (optional type test)4 3.6Dielectric tests (routine test)4 3.7Hygroscopic test (optional type test)4 3.8Short-circuit test (optional type test)4 3.9Test for performance in rain (type test)4 3.10 Condition of resistor after test5 4Rating plate5 4.1General5 Table 1 Tolerances on
13、 the resistance of boxes, frames, blocks or sections of resistors and complete resistors2 Table 2 Tolerances on the resistance of resistor elements2 Table 3 List of tests3 Publications referred toInside back cover Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 01:53:09 GMT+00:00 2006, Uncont
14、rolled Copy, (c) BSI BS 4846:1972 ii BSI 09-1999 Foreword This British Standard has been prepared under the authority of the Electrical Industry Standards Committee. It is based upon IEC Recommendation 322, “Rules for ohmic resistors used in the power circuits of electrically powered vehicles”, and
15、is technically identical to it. 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 confer immunity from legal obligations. Summary o
16、f pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 6, 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 in the amendment table on the inside front c
17、over. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 01:53:09 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4846:1972 BSI 09-19991 1 General 1.1 Scope This British Standard specifies requirements for resistors (for starting, transition, circuit interruption, braking, shunting, stabilizing, e
18、tc.) used in the power circuits of electrically powered vehicles in the following categories: vehicles supplied with so-called high voltage d.c., i.e. with a voltage between 600 V and 3 000 V; vehicles supplied with high voltage a.c. at industrial frequency or at special frequencies; multi-system ve
19、hicles capable of being supplied from a number of the systems described above; vehicles with an independent power source (i.e. accumulators or heat engines with electrical or other transmission), but excluding road vehicles. The standard defines: the conditions that resistors should satisfy, the tes
20、ts to check that the conditions are in fact satisfied and the descriptive markings to be applied. The standard is also applicable to resistors permanently or temporarily inserted in the main auxiliary circuits of the above vehicles, and any trailers and driving trailers in motor coach trains. NOTE 1
21、Parts of this standard may, after agreement between the user and the manufacturer, be used for resistors installed on other vehicles such as d.c. electric rolling stock supplied at voltages below 600 V, mine locomotives, trolley buses, etc. NOTE 2The titles of the British Standards referred to in th
22、is standard are listed on the inside back cover. 1.2 Definitions For the definitions of general terms used in this British Standard reference should be made to BS 205 and BS 4727. For the purposes of this British Standard the following definitions apply: 1.2.1 resistor element a resistive conductor,
23、 designed without break of continuity forming part of a resistance box or frame the elements are usually in the form of grids, plates, strips, ribbons or wires. They may have intermediate tappings 1.2.2 resistor box or frame a set of resistor elements assembled into a single structure 1.2.3 resistor
24、 block a frame or compartment in which a number of resistor boxes or frames are mounted 1.2.4 resistor section part of a resistant circuit contained between two consecutive terminals connected to apparatus such as resistance contactors or controllers 1.2.5 complete starting or braking resistor set o
25、f starting or braking resistors on a vehicle 1.2.6 maximum temperature (tm) the maximum conductor temperature which a resistor box, frame or block can withstand permanently without any resulting damage to the insulants or to their constituent materials 1.2.7 continuous current (Ic) current value spe
26、cified by the manufacturer that a resistor or resistor section can withstand on the test bed for an indefinite period, in specified ventilation or cooling conditions, without the temperature tm being exceeded 1.2.8 rated values of resistances rated values of resistances are specified values. These v
27、alues do not include the resistance of connections between boxes connected in series or in parallel to form a set, nor the resistance of connections to apparatus (contactors, controllers) except where stated otherwise, the rated values of resistance are shown at a temperature of 20 C 1.3 Categories
28、of tests 1.3.1 General. There are three categories of tests: 1) type tests; 2) routine tests; 3) investigation tests. 1.3.2 Type tests. Type tests are those made on a single piece of apparatus of a given design. Equipment in current manufacture is considered to have satisfied the type tests and is e
29、xempted from them, if the manufacturer presents duly signed reports of type tests already made on identical apparatus constructed on a previous occasion. Optional type tests will only be carried out if they have been expressly specified in the order. 1.3.3 Routine tests. Routine tests are those made
30、 on the whole of the equipment of the same order. For certain apparatus, after agreement between the user and the manufacturer, routine tests may be replaced by spot checks on part of the order. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 01:53:09 GMT+00:00 2006, Uncontrolled Copy, (c) BS
31、I BS 4846:1972 2 BSI 09-1999 1.3.4 Investigation tests. Investigation tests are special tests, which are optional, and are made on a single item in order to obtain additional information on its performance; their execution may only be required if they are expressly specified in the order. The result
32、s of investigation tests are not to be taken as influencing the acceptance of the material. 2 Conditions to be satisfied by resistors 2.1 Resistance values Unless otherwise agreed between the user and the manufacturer, the values of resistance measured when cold and corrected, if necessary, to the r
33、eference temperature of 20 C, shall not vary from the rated value by more than the amounts shown in Table 1 and Table 2. Table 1 Tolerances on the resistance of boxes, frames, blocks or sections of resistors and complete resistors Table 2 Tolerances on the resistance of resistor elements 2.2 Tempera
34、ture rises The maximum temperature (tm) of resistors and the permissible temperature rise limits will be determined by agreement between the user and the manufacturer in relation to the nature of the materials used, to the general design of the apparatus and to the temperatures which partitions and
35、adjacent accessories (cables, cable sockets, etc.) are able to withstand. At the request of the user, the manufacturer should submit diagrams showing loading cycles for each resistance section based on the most severe conditions of service (taking into consideration exceptional cases such as motor d
36、amage, slipping, signal at danger, decrease of resistor cooling, etc.) fixed by the user. 2.3 Short-circuit withstand The resistors shall be able to withstand, without deterioration or permanent distortion, short-circuits currents, the value and duration of which will be determined by agreement betw
37、een the user and the manufacturer, having regard to the characteristics of the circuits in which they will be inserted in the vehicle. 2.4 Vibration and shock withstand The resistor boxes or frames mounted complete shall be able to withstand without deterioration: 1) in each of the three directions:
38、 vertical, longitudinal and transverse, sustained sinusiodal vibrations in the frequency range 1 Hz to 50 Hz, the amplitude a of which, expressed in mm, is given in relation to frequency f by the formulae: for 1 Hz to 10 Hz for 10 Hz to 50 Hz; 2) in the direction corresponding to the longitudinal mo
39、vement of the vehicle, shocks producing maximum accelerations of 3 g (g being the value of acceleration due to gravity). In addition, the elements and accessories of the resistors shall not exhibit harmful resonance for the frequencies in the above range. 2.5 Protection against corrosion All precaut
40、ions shall be taken to give adequate protection against corrosion for all the components of the resistor, especially contact surfaces. 2.6 Performance in rain and snow If the resistors are to be installed on a vehicle in such a way that they are exposed to rain and snow, they shall be able to withst
41、and the effects of these elements without mechanical or electrical damage. 3 Tests 3.1 List of tests The type and routine tests to be made on resistors are indicated in Table 3, which also specifies the clause or subclause number to which reference should be made. Resistor typeTolerances Starting re
42、sistor Braking resistor Permanent shunting resistor Shunting resistor for field weakening of direct or pulsating current motors 1) weak field between 100 % and 50 % of full field 2) weak field less than 50 % of full field 3) adjustable resistors Shunting resistor for interpoles of single-phase commu
43、tator motors Circuit interrupting resistor % + 7, 5 5 3 + 7, 5 3 10 Nature of resistor elementTolerances Cast grids Ribbons, wires, etc. % 10 5 a 25 f -= a 250 f2 - -= Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 01:53:09 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4846:1972 BSI 09-19993
44、 Table 3 List of tests 3.2 Check on characteristics of resistor material (type test) The resistivity and the average value of the temperature coefficient over the range between the ambient and maximum operating temperatures (tm) will be determined from test pieces taken from the alloy forming the re
45、sistor material. 3.3 Check on rated resistance (type and routine tests) 3.3.1 Checks on the rated value of resistance for resistor boxes, frames, blocks, resistor sections or complete resistors are carried out by using a voltmeter and ammeter, or Kelvin double bridge, the current through the resisto
46、rs being sufficient to eliminate the errors due to contact resistances. Readings are taken at the ambient temperature of the workshop. If necessary, the values measured are to be corrected to the reference temperature of 20 C. The tolerances allowed in relation to the rated values are shown in Claus
47、e 2.1. 3.3.2 Resistance measurements are repeated at the end of the temperature-rise test described in Subclause 3.4.2. The resistance increase noted should approximate to the value calculated on the basis of the temperature coefficient determined during the tests described in Clause 3.2. 3.3.3 When
48、 the temperature-rise tests are complete, the resistor is to be allowed to cool down until it reaches ambient temperature. The resistance is then to be measured again and the value obtained compared with that measured before the temperature-rise test was carried out. The second reading shall not exc
49、eed the first by more than 3 % and shall, in any case, remain within the limits of tolerance given in Table 1. 3.4 Temperature-rise tests (type tests) 3.4.1 General. The temperature-rise tests are made on a finished and mounted resistor installed in conditions as close as possible to those on the vehicles, especially in regard to the cross-section of the connecting leads, the resistor position, etc. The cooling conditions shall be mutually agreed between the user and the manufacturer so as to reproduce the normal service conditio
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