1、 W 3404583 0024345 8 = &. . 1 SHEET issue i 1987-06-29 - -e- .?u BC4dm7dl. 2 - ata J - 1oM BNXd14 TTI Qbll9 a II - Teh U57 TOW- (4 t) Sl9 6s 19 - Tdu I_- Safety of household and similar electrical appl fances. General requirements Skurite des appareils Lectrodoatestiques et analogues. Rgles gnerales
2、 Zwecke. Allgemeine Anforderungen Sicherheit elektrischer Gerate fGr en Hausgebrauch und Ihnifche RD: HO 251 83 .* -Y_- The Harmonization Document consists af the foLLowing : - TitLc Page Related to Directive: 73/23/EEC - Text prepared by CENELEC TC 6 - -_I- date of ratification : 1987-05-04 da te o
3、f announcement I 987-07-0 date of latest publication : 1988-01-01 date of withdrawal : 1988-07-01 HARPKX(1ZED NATONAL STANDARDS AT : BE : I I CH : OE : Df : ES : FI : FR : GE : GR : . IT : LU : NL : NO : PT : 3404583 O024346 T = CEPELEC Central Secretariat Rue Brderode 2 - Boite 5 B - 1000 Bruxelles
4、 Tel. 02-519 6871 Telex 26257 Cenlec b AMENDMENT 3 TO HD 251 S3 DATE OF ISSUE: 7987-06-29 dop: 1988-01-01 dow: 1988-07-01 doa: 1987-07-01 ENGLISH VERSION SAFETY OF HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES GENE- REQUIREMENTS Scurith des appareils Qlectro- domestiques et analogues. rate fr den Haus
5、gebrauch und Rgles gnrales. hnliche Zwecke Si Che rhe i t e 1 ek tr i s ch e r Ge- Allgemeine Anforderungen. This Amendment 3 to HD 251 S3 was prepared by CENELEC/TC 61 on the basis of the decisions taken at its meetings held in Athens in October 1985 and in Nice in November 1986. It was ratified by
6、 the Technical Board at its meeting held in Brussels on 1987-03-04. It supplements HD 251 S3. The changes to be made to the text of the HD are given hereafter. (c) Copyright reserved to all CENELEC members m CENELEC -2- 3404583 0024347 L Amendment 3 to HD 251 S3 April 1987 FOREWORD This Amendment 3
7、to HD 251 S3 has been prepared by the Secretariat of CENELEC Technical Committee 61 in accordance with the relevant decisions taken by that committee during its meetings held in October 1985 in Athens and in November 1986 in Nice. During the meeting held in Athensl it was decided to circulate a draf
8、t for that amendment for approval under the three months voting procedure. The result of the three months voting procedure being favourable, it was decided to publish this amendment in the CENELEC member countries before January Ist, 1988. This latest date of publication was confirmed by the Technic
9、al Board during its meeting held in March 1987 in Brussels. During the latter meeting, the Technical Board decided also that conflicting non-harmonized national standards should be withdrawn before July Ist, 1988. This amendment is provisional and intended to improve the usefulness of the tests of A
10、ppendix B: it will be used until a harmonized revision of Appendix B exists. Note. There are no national deviations from this amendment other than those specified in the list of national deviations from HD 251 53. 3404583 0024348 3 = CENELEC -3- Amendment 3 to HD 251 S3 April 1987 ENDORSEMENT NOTICE
11、 The following common modification supplements those given in HD 251 S3. 1 CLAUSE 1 COMMON MODIFICATION 1 JUSTIFICATION f I 1 1 I 1 1 1 l I 1 1 B19 1 Replace this clause of Appendix B 1 This modification1 1 1 by the text given in Appendix 2 1 is considered to I 1 I to this Harmonization Document. I
12、be necessary to 1 I 1 I improve the use- 1 I I 1 fulnecs of Appen-1 1 I 1 dix B. 1 I l I 1 l 1 f f 1 f CENELEC B19 m 3404583 O024349 5 m Appendix 2 to HD 251 S3 April 1987 Abnormal operation 519 * 101 Electronic circuits shall be so designed and applied that any fault condition will not render the a
13、ppliance unsafe with regard to electric shock, fire hazard, mechanical hazard or dangerous malfunction. Compliance is checked by evaluating the fault con- ditions specified in Sub-clause B19.103 for all circuits or parts of circuits, taking into account the conditions specified in Sub-clause B19.102
14、. If the safety of the appliance under any of the fault conditions depends on the operation of a miniature fuse- link, acceptability of this provision is checked by the test of Sub-clause B19.104. During and after each test, the temperature of windings shall not exceed the values specified in the ta
15、ble of Sub-clause 19.6 and the appliance shall comply with the conditions specified in Sub-clause 19.11. In particu- lar, live parts shall not be accessible to the standard test finger or the test pin, as specified in Sub-clause After the tests, basic insulation, supplementary insu- lation and reinf
16、orced insulation shall withstand an electric strength test as specified in Sub-clause 16.4. If a conductor on a printed circuit board opens, the appliance is considered to have withstood the particu- lar test, provided all three of the following conditions are met: - the material of the printed circ
17、uit board withstands the burning test of Sub-clause 20.1 of HD 195 S4: - any loosened conductor does not reduce the creepage distances or clearances between live parts and accessible metal parts below the values specified in Clause 29, - the appliance withstands the tests of Sub-clause B19.103 with
18、the interrupted conductor bridged. 8.1 Unless it ih: necessary to replace components after any of the tests, the electric strength test need only be carried out after the final test on the electronic circuit. In general, examination of the appliance and its circuit diagram will reveal the fault con-
19、 ditions which have to be simulated, so that testing can be limited to those cases which may be expected to give the most unfavourabie re s u 1% In certain cases, it may be preferable to simulate all fault conditions rather than to dnalyze the circuit diagram. Examples of constructions of appliances
20、 in- corporating electronic circuits are shown in Figure B1. W 3404583 0024350 L CENELEC -2- Appendix 2 to HD 251 S3 April 1987 B19 102 l%e.fault conditions 1) to 5) specified in Sub-clause B19.103 are not applied to circuits or parts of circuits where all three of the following conditions are met:
21、- the electronic circuit is supplied by an extra-low voltage transformer or through a limiting impedance, provided the ciruit is a low-power circuit as desribed below, - the requirements of Sub-clause 8.1 are met, even with one component of the limiting impedance short-cir- cuited or open-circuited
22、or with the basic insulation between the input winding and output winding of an extra-low voltage transformer bridged, - the protection against electric shock, fire hazard, mechanical hazard or dangerous malfunction in other parts of the appliance does not rely on the correct , functioning of the el
23、ectronic circuit. A low-power circuit is determined as follows and further explained in Figure B2. The appliance is operated at rated voltage or at the upper limit of the rated voltage range and a variable resistor, adjusted to its maximum resistance, is con- nected between the point to be investiga
24、ted and the opposite pole of the supply source. The resistance is then decreased until the power con- sumed by the resistor reaches a+maximum. Any point nearest. to the supply source at which the maximum power delivered to this resistor does not exceed 15 W after 5 8, is called a low-power point. Th
25、e part of the circuit farther from the supply source is considered to be a low-power circuit. The measurements are made only from one pole of the supply source, preferably the one that gives the fewest low-power points. When determining the low-power points, it is re- commended to start with points
26、close to the supply SOUTt? c19.103 The following fault conditions are considered and, if necessary, applied one at a time, together with any consequential fault. i) Short-circuit of creepage distances and clearances between live parts of different polarity, if these distances are less than the value
27、s specified in Clause B29, unless the relevant part is adequately encapsulated. m 3404583 0024353 3 m CENELEC , -3- Appendix 2 to HD 251 S3 April 1987 2) Short-circuit between live parts of different polarity across insulation which does not withstand the tests of Clause 16. 3) Open-circuit at the t
28、erminals of any component. 4) Choit-circuit across resist&s and capacitors , un- less: - the resistor withstands the tests of Sub-clause 14.1 of HD 195 S4: - the capacitor withstands the tests of Sub-clause 14.2 of AD 195 C43 provided it is used in circuits where the peak voltage across its terminal
29、s does not exceed 354 V, - the capacitor complies with IEC Publication 384-14. 5) Short-circuit across any two terminals of electronic devices and of electronic units. 6. Short-circuit of each lower-power circuit by con- necting the low-power point to the pole of the . supply from which the measurem
30、ents are made. For the simulation of the fault conditions, the appliance is operated under the conditions specified in Clause 11, but at rated voltage or at the most un- favourable voltage within the rated voltage range a If any of the fault conditions have to be simulated, the duration of the test
31、is: - as specified in Sub-clause 11.7, but only for one operating cycle and only if the fault cannot be re- cognized by the user, for example, a change in , temperature setting: - as specified in Sub-clause 19.6, if the fault can be recognized by the user, for example, when the motor of a kitchen ma
32、chine stops: - until steady corditions are established, for circuits continuously connected to the supply mains, for . example, stand-by circuits. In each case, the tess,iq considered to be ended if interruption of the _current occursa Fault condition 5) is not applied in the case of discrete compon
33、ents, such as opto-couplers, pro- vided with insulation withstanding the tests of Clauses 16 and 29. CENELEC -4- Appendix 2 to HD 251 S3 April 1987 B19 * 104 If, for any of the fault conditions specified in Sub- clase B19.103, the safety of the appliance depends on the operation of a miniature fuse-
34、link complying with HD 109 S3L2 it is verified that the fuse-link is able to act as a protecting device by replacing the miniature fuse-link by an ammeter for the relevant test. If the current measured does not exceed 2.1 times the rated current of the fuse-li., the circuit is not con- sidered to be
35、 adequately protected and the test is carried out with the fuse-link short-circuited. If the current measured is at least 2.75 cimes the rated current of the fuse-link, the circuit is considered to be adequately protected. If the current measured exceeds 2.1 times the rated current of the fuse-link,
36、 but does not exceed 2.75 times the rated current, the fuse-link is short- circuited and the test is carried out for the relevant period or for: - 2 min for time-lag fuse-links, - 30 min for quick-acting fuse-links, whichever is the shortest period. In case of doubt, the maximum resistance of the fu
37、se-link has to be taken into account when determining the current. The verification whether the fuse-link acts as a protecting device is based on the,fusing characteristics specified in HD 109 S3) which also gives the information necessary to calculate the maximum resistance of the fuse- link. 34045
38、83 004353 7 .,CLLC -5- I N 4 N FIG. BI. - Examples of constniaioo, or appliances hcorpontinp electronic circuits. C ENEL EC 3404583 0024354 9 -6- Appendix 2 to HD 251 53 &ri1 1987 O: A and B: point farthest from the supply source where the available power exceeds 15 W. points closest to the supply s
39、ource where the available power does not exceed 15 W. Points A and B are separately short-circuited to point G. The fault conditions i) to 5) specified in Sub-clause 819.103 are applied one at a time to 21. tp, tJ, t6, and t7, if necessary. * * Fig. 82 Example of an electronic circuit with low-power points
