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1、BRITISH STANDARD BS 842:1965 Incorporating Amendment No. 1 Specification for A.C. voltage-operated earth-leakage circuit breakers UDC 621.316.57.025:621.316.9 Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 02:06:39 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS
2、842:1965 This British Standard, having been approved by the Electrical Industry Standards Committee and endorsed by the Chairman of the Engineering Divisional Council, was published under the authority of the General Council on 15 November 1965 First published June 1939 First revision November 1965
3、BSI 10-1999 The following BSI references relate to the work on this standard: Committee references ELE/10 and ELE/10/18 Draft for comment D64/1587 ISBN 0 580 01330 8 Co-operating organizations The Electrical Industry Standards Committee under whose supervision this British Standard was prepared cons
4、ists of representatives from the following Government departments and scientific and industrial organizations: Associated Offices Technical Committee Association of Consulting Engineers* Association of Mining Electrical and Mechanical Engineers* Association of Supervising Electrical Engineers* Briti
5、sh Electrical and Allied Manufacturers Association* British Railways Board* Cable Makers Association* Crown Agents for Oversea Governments and Administrations* Electric Lamp Industry Council Electric Light Fittings Association Electrical Contractors Association (Incorporated)* Electrical Contractors
6、 Association of Scotland Electrical Research Association* Electricity Council, The Generating Board and the Area Boards in England and Wales* Electronic Engineering Association Engineering Equipment Users Association* Independent Cable Makers Association Institution of Electrical Engineers* Ministry
7、 of Aviation* Ministry of Defence, Army Department* Ministry of Defence, Navy Department* Ministry of Labour (H.M. Factory Inspectorate)* Ministry of Power* Ministry of Public Building and Works* Municipal Passenger Transport Association (Incorporated) National Inspection Council for Electrical Inst
8、allation Contracting* National Physical Laboratory (Ministry of Technology) Oil Companies Materials Association* Post Office* Public Transport Association (Incorporated) South of Scotland Electricity Board* The Government departments and scientific and industrial organizations marked with an asteris
9、k in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Association of Short-circuit Testing Authorities Engineer Surveyors Association Lloyds Register of Shipping London Transport Board National Coal Board
10、 Amendments issued since publication Amd. No.DateComments 3259March 1980Indicated by a sideline in the margin Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 02:06:39 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 842:1965 BSI 10-1999i Contents Page Co-operating
11、organizationsInside front cover Forewordiii 1Scope1 2Definitions1 3Service conditions1 4Rating1 5Standard arrangement of poles2 6Standard voltage ratings2 7Standard current ratings2 8Frequency2 9Marking2 10Terminal identification2 11Temperature rise2 12Earth-leakage performance3 13Test device3 14Mai
12、ns operated trip coils3 15Construction3 16Operating mechanism4 17Connection arrangements4 18Test requirements general4 19Test certificates4 20Type tests4 21Temperature rise test5 22Operation of the test device5 23Endurance test5 24Making and breaking test6 25Through current test6 26Resistance to lig
13、htning surges6 27Routine tests7 28Performance test7 29Speed of operation7 30Performance of test device7 31Mains voltage test on tripping device7 32High-voltage test7 Appendix A Service conditions8 Appendix B Application of earth-leakage circuit-breakers8 Appendix C Method of installation8 Appendix D
14、 Function of the test device9 Appendix E Effect of earth-electrode resistance10 Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 02:06:39 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 842:1965 ii BSI 10-1999 Page Figure 1 Typical test circuit for through current
15、test11 Figure 2 Circuit for surge test12 Figure 3 Typical voltage-operated earth-leakage circuit-breaker installation. Note insulated lead from “e” to earth electrode13 Figure 4 Typical voltage distribution in soil surrounding a 2 m rod electrode14 Table 1 Voltage ratings2 Table 2 Current ratings2 T
16、able 3 Temperature rise3 Table 4 Operating limits3 Table 5 Terminal capacities4 Table 6 Endurance test sequence6 Table 7 Prospective-current values6 Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 02:06:39 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 842:1965 B
17、SI 10-1999iii Foreword This standard makes reference to the following British Standards: BS 2757, Classification of insulating materials for electrical machinery and apparatus on the basis of thermal stability in service. BS 3042, Standard test finger (for checking protection against electric shock)
18、. This British Standard for voltage-operated air-break earth-leakage circuit-breakers is an extensive revision of the 1939 edition to take account of modern developments in earth-leakage protection and in the design and production of small circuit-breakers. The voltage-operated type of earth-leakage
19、 circuit-breaker is intended to prevent a dangerous potential difference persisting between the general mass of earth and accessible installation metal work. The operation of the device will depend not only upon this potential difference but also upon the earth-leakage circuit-breaker earth-electrod
20、e resistance (see Appendix E). A voltage-operated earth-leakage circuit-breaker may incorporate over-current protection. In such instances it is necessary for the earth-leakage circuit-breaker to comply with the requirements of this standard and also with the relevant requirements in the appropriate
21、 circuit-breaker standard. In this connection, attention is drawn to BS 3871-11) and BS 8622). Appendices have been included to assist users in the proper application of voltage-operated earth-leakage circuit-breakers and attention is particularly directed to these. A British Standard for the curren
22、t-operated type of earth-leakage circuit-breaker is in the course of preparation and this type of circuit-breaker will be more suitable for low-values of earth-loop impedance. NOTEIn place of the customary, but incorrect use of the ounce as a unit of force, the unit called ounce-force (abbreviation
23、ozf) has been used in this standard. This is the force which, when acting on a body of mass one ounce, gives it an acceleration equal to that of standard gravity. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for
24、 their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 14 and a back cover. This standard has been updated (see copyright date)
25、and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. 1) BS 3871, “Miniature and moulded-case circuit-breakers”, Part 1, “Miniature air-break circuit-breakers for a.c. circuits”. 2) BS 862, “Air-break circuit-breakers (including totally en
26、closed and flameproof types) for voltages not exceeding 660 volts”. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 02:06:39 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08
27、 02:06:39 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 842:1965 BSI 10-19991 1 Scope This British Standard specifies requirements for a.c. voltage-operated earth-leakage circuit-breakers having rated voltages not exceeding 500 volts and rated currents not exceeding 200 amperes (see Appendix B, Appe
28、ndix C and Appendix E). 2 Definitions For the purposes of this British Standard the following definitions apply: 2.1 voltage-operated earth-leakage circuit-breaker (hereinafter referred to as circuit-breaker) a device for making and breaking a circuit, and for breaking a circuit automatically when t
29、he potential difference between protected metal work of the electrical installation and the general mass of earth exceeds the values specified in Clause 12 2.2 number of poles the number of main conducting paths which the circuit-breaker is required to open or close simultaneously 2.3 switched neutr
30、al contacts not intended to make or break current and arranged to close before and open after the main contacts for the purpose of isolating the neutral 2.4 prospective current the current (r.m.s. value of the a.c. component) that would flow in a circuit due to the applied voltage if the circuit-bre
31、aker were replaced by a link or links of negligible impedance but without any other circuit change NOTEFor the purpose of this definition the term circuit-breaker includes the short length of cable used to connect the circuit-breaker to the test circuit. 2.5 main contacts the fixed and moving contac
32、ts in the main current-carrying circuit 2.6 auxiliary contacts contacts working in conjunction with, and actuated by the circuit-breaker, and serving to control the operation of auxiliary devices such as trip coils or audible alarms 2.7 leakage trip coil a coil energized directly by voltage between
33、earth and the protected metal work and which directly or indirectly operates the mechanism when this voltage exceeds a specified value 2.8 mains-operated trip coil a coil energized by the supply voltage controlled by a leakage trip coil (acting as a relay) to operate the mechanism 2.9 test device a
34、device to enable the protective function of the circuit-breaker to be checked 2.10 rating of a circuit-breaker the values assigned by the manufacturer to define the working conditions for which the circuit-breaker is made 2.11 applied voltage the r.m.s. value of the voltage applied to a test circuit
35、 immediately before the initiation of current 3 Service conditions (See Appendix A) Voltage-operated earth-leakage circuit-breakers shall be suitable for use in the following conditions of service: 1) An ambient temperature not less than 5 C and not exceeding 35 C and having an average value not exc
36、eeding 30 C measured over a 24-hour period. NOTECircuit-breakers complying with this standard may not be suitable for exposure to direct radiation from the sun or other sources of heat likely to raise temperature above the designated ambient. 2) An earth-loop impedance not exceeding 500 ohms. 3) An
37、altitude not exceeding 2 000 m above sea level. 4) An atmosphere not subject to conditions giving rise to excessive pollution. 4 Rating Circuit-breakers shall be rated in the following terms: 1) Number of poles. 2) Voltage. 3) Current. 4) Frequency. Licensed Copy: London South Bank University, Londo
38、n South Bank University, Fri Dec 08 02:06:39 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 842:1965 2 BSI 10-1999 5 Standard arrangements of poles The following arrangements of poles shall be standard: 6 Standard voltage ratings The voltage ratings contained in Table 1 shall be standard. Table 1 Vol
39、tage ratings 7 Standard current ratings The current ratings contained in Table 2 shall be standard. Table 2 Current ratings 8 Frequency The frequency for the purposes of this standard shall be 50 cycles per second. NOTECircuit-breakers having voltage, current or frequency ratings other than the valu
40、es given in Clauses 6, 7 and 8 may be considered as standard provided that they comply in all other respects with the specification. 9 Marking Circuit-breakers shall be marked indelibly with the following particulars: 1) Rated voltage. 2) Rated voltage to earth if other than 240 volts. 3) Rated curr
41、ent. 4) Frequency. 5) “A.C.” or “”. 6) Manufacturers name or distinguishing mark. 7) Manufacturers type reference when more than one type is manufactured. 8) Country of manufacture. 9) BS 842. 10) The operation of the test device. (This shall be clearly indicated.) When the marking is on a cover whi
42、ch is not sealed in position by the manufacturer the marking of the rated current shall also appear on the main body of the circuit-breaker. 10 Terminal identification The terminals of the circuit-breaker shall be clearly and permanently marked for identification. When in addition, the design of the
43、 circuit-breaker is such as to make it necessary to distinguish between the line and load terminals, the former shall be indicated by arrows pointing towards the circuit-breaker and the latter by arrows pointing away from the circuit-breaker. A diagram showing the correct method of connecting the ci
44、rcuit-breaker shall be formed on, or secured to, each circuit-breaker. NOTEIt is not intended that this diagram should take the form of an internal wiring diagram. It may be formed on the inside of a cover removable for installation purposes. The following terminal markings shall be used: 11 Tempera
45、ture rise The temperature rise at specified locations in a circuit-breaker tested in accordance with Clause 21 shall not exceed the values given below: Single pole and switched neutral Double pole For single phase supply Triple pole Triple pole and switched neutral Four pole For three phase supply S
46、tandard voltage rating Voltage to earth 240 415 240 240 Amperes 15 30 60 100 200 NeutralFrameEarth Nf or F or frame e or E or earth NOTEFor clarity lower case letters f and e are desirable. 1) Terminals of circuit-breakers fitted with copper contacts:35 degC 2) Terminals of circuit-breakers fitted w
47、ith contacts having adequate and durable facings of silver or similar materials not subject to progressive deterioration:50 degC 3) Handles, operating devices and parts of enclosures likely to be handled when operating the circuit-breaker:35 degC 4) Insulating material not likely to be handled in se
48、rvice, including that of the leakage trip coil:as given in Table 3 Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 02:06:39 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 842:1965 BSI 10-19993 Table 3 Temperature rise NOTEDetails of insulating materials covered b
49、y the classes specified in Table 3 are contained in BS 2757, “Classification of insulating materials for electrical machinery and apparatus on the basis of thermal stability in service”. 12 Earth-leakage performance Circuit-breakers shall operate within the limits specified in Table 4 when tested in accordance with Clause 28. Table 4 Operating limits 13 Test device Circuit-breakers shall be provided with a test device which shall first open the connection between one side of the leakage trip coil and the fra