1、BRITISH STANDARD BS EN 60512-5-2:2002 Connectors for electronic equipment Part 5-2: Current-carrying capacity tests Test 5b: Current-temperature derating The European Standard EN 60512-5-2:2002 has the status of a British Standard ICS 31.220.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED B
2、Y COPYRIGHT LAWBS EN 60512-5-2:2002 This British Standard, having been prepared under the direction of the Electrotechnical Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 6 June 2002 BSI 6 June 2002 ISBN 0 580 39731 9 Nationa
3、l foreword This British Standard is the official English language version of EN 60512-5-2:2002. It is identical with IEC 60512-5-2:2002. The UK participation in its preparation was entrusted by Technical Committee EPL/48, Electromechanical components and mechanical structures for electronic equipmen
4、t, to Subcommittee EPL/48/2, Connectors for electronic equipment, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on request to its secretary. From 1 January 1997, all IEC publications have the number 60000 added to the old number. For instan
5、ce, IEC 27-1 has been renumbered as IEC 60027-1. For a period of time during the change over from one numbering system to the other, publications may contain identifiers from both systems. Cross-references The British Standards which implement international or European publications referred to in th
6、is document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Use
7、rs of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation,
8、or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 7, and a back cover. The BSI copyright date
9、 displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD EN 60512-5-2 NORME EUROPENNE EUROPISCHE NORM April 2002 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation
10、Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60512-5-2:2002 E ICS 31.220.10 English version Conne
11、ctors for electronic equipment - Tests and measurements Part 5-2: Current-carrying capacity tests - Test 5b: Current-temperature derating (IEC 60512-5-2:2002) Connecteurs pour quipements lectroniques - Essais et mesures Partie 5-2: Essais de courant limite - Essai 5b: Taux de rduction de lintensit e
12、n fonction de la temprature (CEI 60512-5-2:2002) Steckverbinder fr elektronische Einrichtungen - Mess- und Prfverfahren Teil 5-2: Prfungen der Strombelastbarkeit - Prfung 5b: Strombelastbarkeit (Derating-Kurve) (IEC 60512-5-2:2002) This European Standard was approved by CENELEC on 2002-04-01. CENELE
13、C members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on app
14、lication to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secreta
15、riat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and Un
16、ited Kingdom.The text of document 48B/1137/FDIS, future edition 1 of IEC 60512-5-2, prepared by SC 48B, Connectors, of IEC TC 48, Electromechanical components and mechanical structures for electronic equipment, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60512-5-
17、2 on 2002-04-01. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2003-01-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2005
18、-04-01 _ Endorsement notice The text of the International Standard IEC 60512-5-2:2002 was approved by CENELEC as a European Standard without any modification. _ Page2 EN6051252:2002 BSI6June2002065-21-52 EI:C0022 3 CONNECTORS FOR ELECTRONIC EQUIPMENT TESTS AND MEASUREMENTS Part 5-2: Current-carrying
19、 capacity tests Test 5b: Current-temperature derating 1 Scope and object This part of IEC 60512, when required by the detail specification, is used for testing electro- mechanical components within the scope of IEC technical committee 48. This test may also be used for similar devices when specified
20、 in a detail specification. The object of this test is to detail a standard test method to assess the current-carrying capacity of electromechanical components at elevated ambient temperature. 2 General conditions 2.1 Determining the current-carrying capacity curve The current-carrying capacity is l
21、imited by the thermal properties of the materials which are used for the contacts, terminals as well as the insulating materials of housing. Therefore, it is a function of the self-generated heat and the ambient temperature at which a device operates. Using the measuring conditions given in 3.2, the
22、 temperature t b of a measuring point (approximately the hottest spot) of the component and the temperature t uin the immediate environment of the component are measured at various currents. The difference between the two temperatures is the self-heating or rise created by the current flow. This may
23、 be expressed as: t b t u= t (K) The relation between the current, the temperature rise and the ambient temperature of the component is represented by a curve as shown in figure 1. Unless otherwise specified in the detail specification, the temperature rise is based upon the mean current of three sp
24、ecimens. The mean value derived from the measured values of these three specimens serves as the basic curve. At least three points of the basic curve shall be established. The permissible upper-limit temperature of the materials employed is plotted as a vertical line on the graphs shown in figures 1
25、 and 2, with current I as the ordinate and temperature t as the abscissa. The temperature rise t (mean value of three specimens), determined at current I n , is deducted. From this, the maximum permissible ambient temperature t ufor the load current I nis obtained, since the sum of the ambient tempe
26、rature t uand the temperature rise t shall not exceed the upper temperature limit of the materials. Page3 EN6051252:2002 BSI6June2002065-21-52 EI:C0022 4 t 3 t 2 t 1 Current I I 3 I 2 I 1 t 3 t 2 t 1 Upper limit of temperature Ambient temperature t IEC 546/02 NOTE An upper temperature limit, which m
27、ay be imposed by e.g. material considerations, may truncate the curve. Figure 1 Construction of the basic current-carrying curve 2.2 Derating curve A derating curve, see figure 2, derived from the basic curve, see figure 1, determined in accordance with 2.1, shall be specified in the relevant detail
28、 specification. This curve takes into account variations in specimens as well as errors in temperature measurements in the measuring equipment. The derating factor is justified because the current-carrying capacity may be further limited by external factors, for example the size of the wire and uneq
29、ual distribution of the loaded circuits. If these factors result in a current-carrying capacity other than that which may be expected due to thermal limitations, then a revised value shall apply. 2.3 Application of the current-carrying capacity curve The derating curve determined in accordance with
30、2.2 represents the official current-carrying capacity curve as defined by this standard. Since it gives the maximum permissible current as a function of the ambient temperature, it is truly a derating curve. The cross-hatched area shown in figure 2 indicates the permissible operating range. This der
31、ating curve is obtained by applying a reduction factor of 0,8 on the current value of the basic current-carrying curve, unless otherwise clearly specified on the derating curve. NOTE If the detail specification specifies current-carrying capacity data, then the current-carrying capacity curve given
32、in this standard must be cited. If values in tabular form are preferred, they should coincide with the current- carrying capacity curve. Page4 EN6051252:2002 BSI6June2002065-21-52 EI:C0022 5 I n (Possible) Upper current limit (Derated) Operating area Upper temperature limit Basic curve Derated curve
33、 0,8 I n IEC 547/02 Current I Ambient temperature t Figure 2 Derating curve derived from the basic curve 3 Conditions of the test 3.1 Test set-up Enclosure The measurement shall be carried out in air as undisturbed as possible. Therefore, the specimen shall be mounted in an enclosure which protects
34、the immediate environment from external movements of air. The enclosure should be made of a non-heat- reflective material. The sides of the enclosure may be movable to accommodate different specimen sizes. The sides shall not be closer than 200 mm from the edges of the specimen. The enclosure may ha
35、ve a lid, any such lid shall be provided with ventilation apertures to minimize any rise in ambient temperature caused by the heating effect of the specimen under test. Mounting The specimen is to be arranged in the enclosure in a horizontal plane, 50 mm above the bottom of the enclosure and at leas
36、t 150 mm below the top and equidistant from the sides. As far as possible, the specimen shall be in free suspension. If this is not possible, a thermal insulating material with a thermal conductivity 2 W/mK may be used, provided that not more than 20 % of the surface of the specimen is in contact wi
37、th the insulating material. Wiring The specimen shall be connected with wires of suitable cross-section for the maximum current to be expected or according to the size of the termination. In order to reduce external heat dissipation to a minimum, at least the length of the connecting wires given in
38、table 1 shall be within the measuring enclosure. In the case of multipole specimens, all contacts shall be wired in series with wire the same size as the connecting wires. These links shall be at least twice the minimum length specified in table 1. The manufacturers recommended, or industry standard
39、s, wiring method and tooling shall be used, unless otherwise stated in the detail specification. NOTE In the case of specimens with moving contacts, care must be taken that the contacts are not disturbed by the connecting wires. A mated connector set is considered to be a single specimen. Page5 EN60
40、51252:2002 BSI6June2002065-21-52 EI:C0022 6 Table 1 Minimum wire length for each specimen Wire size mm 2 Minimum length mm 5 1 400 NOTE This table is based on heat conduction criteria, and is designed to ensure that the wires are long compared with their cross-section. If the specimens require the u
41、se of printed circuits, the characteristics of these should be given in the detail specification. 3.2 Conditions of temperature measurement If temperatures are measured with temperature probes, the probe leads shall pass through the insulation walls of the enclosure. Other methods of temperature mea
42、surement are permissible. The measuring point for measuring the ambient temperature shall be located in a horizontal plane passing through the axis of the specimen. It shall be located 50 mm from the mid-point of the edge of the longest side of the specimen. Care shall be taken to protect the probe
43、against radiant heat. The point for measuring the temperature of the specimen shall be as near as practicable to the hottest part of each specimen. NOTE The temperature probes may be thin thermocouples, e.g. nichrome/nickel wire with a diameter 0,3 mm. If thermocouples with the same type of calibrat
44、ion curve are used for both temperature probes, they may be connected in opposition in the measuring circuit. In this case, the temperature rise t is measured directly. However, t bshould be monitored to ensure that it does not exceed the upper temperature limit of the materials. 4 Method of measure
45、ment The specimen shall be arranged in the enclosure as described in 3.1 and its terminals are connected to a regulated power supply through an ammeter, see figure 3. The loading current may be a.c. or d.c. When a.c. current is used, the r.m.s. value applies. If d.c. current is used, avoid voltage b
46、ias influence on the thermocouple by executing the test with reverse current. The current shall be maintained for a period of approximately 1 h after thermal stability is achieved at each of the selected current levels. This is defined as when three consecutive values of temperature rise, taken at 5
47、 min intervals, do not differ by more than 2 K of each other. Page6 EN6051252:2002 BSI6June2002065-21-52 EI:C0022 7 Regulated current supply A mV Specimen Enclosure t b t u t IEC 548/02 Figure 3 Typical arrangement of the measuring apparatus 5 Details to be specified When this test is required by th
48、e detail specification, the following details shall be specified: a) mounting of specimen; b) wire size and type; c) upper temperature limit; d) any deviation from the standard test method. Page7 EN6051252:2002 BSI6June2002BS EN 60512-5-2:2002 BSI 389 Chiswick High Road London W4 4AL BSI British Sta
49、ndards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions British Standards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amendments or editions. It is the constant aim of
