1、DRAFT FOR DEVELOPMENTDD IEC/TS 60695-8-3:2008Fire hazard testing Part 8-3: Heat release Heat release of insulating liquids used in electrotechnical productsICS 13.220.40; 29.020g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54
2、g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58DD IEC/TS 60695-8-3:2008This Draft for Development was published under the authority of the Standards Policy and Strategy Committee on 31 July 2008 BSI 2008ISBN 978 0 580 56465 9National forewordThis Draft for Development i
3、s the UK implementation of IEC/TS 60695-8-3:2008.This publication is not to be regarded as a British Standard.It is being issued in the Draft for Development series of publications and is of a provisional nature. It should be applied on this provisional basis, so that information and experience of i
4、ts practical application can be obtained.Comments arising from the use of this Draft for Development are requested so that UK experience can be reported to the international organization responsible for its conversion to an international standard. A review of this publication will be initiated not l
5、ater than three years after its publication by the international organization so that a decision can be taken on its status. Notification of the start of the review period will be made in an announcement in the appropriate issue of Update Standards.According to the replies received by the end of the
6、 review period, the responsible BSI Committee will decide whether to support the conversion into an international Standard, to extend the life of the Technical Specification or to withdraw it. Comments should be sent to the Secretary of the responsible BSI Technical Committee at British Standards Ho
7、use, 389 Chiswick High Road, London W4 4AL.The UK participation in its preparation was entrusted to Technical Committee GEL/89, Fire hazard testing.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the n
8、ecessary provisions of a contract. Users are responsible for its correct application.Amendments/corrigenda issued since publicationDate CommentsIEC/TS 60695-8-3Edition 1.0 2008-04TECHNICAL SPECIFICATIONFire hazard testing Part 8-3: Heat release Heat release of insulating liquids used in electrotechn
9、ical products DD IEC/TS 60695-8-3:2008CONTENTS INTRODUCTION.3 1 Scope.4 2 Normative references .4 3 Terms and definitions .4 4 General description of the test7 5 Test apparatus .7 5.1 Cone calorimeter.7 5.2 Test specimen tray7 5.3 Position of the test specimen tray8 6 Calibration8 7 Preparation of t
10、he test specimen 8 8 Test method .9 8.1 Critical ignition flux determination9 8.1.1 Introduction .9 8.1.2 Procedure9 8.2 Test procedure 9 9 Calculation .9 10 Test report9 11 Precision data 10 Annex A (informative) Precision data .11 Bibliography12 Figure 1 Example of test specimen tray .8 DD IEC/TS
11、60695-8-3:2008 2 INTRODUCTION In the design of any electrotechnical product, the risk of fire and the potential hazards associated with fire need to be considered. In this respect, the objective of component, circuit and equipment design, as well as the choice of materials, is to reduce to acceptabl
12、e levels the potential risks of fire even in the event of foreseeable abnormal use, malfunction or failure. The future IEC 60695-1-10 11, together with its companion, the future IEC 60695-1-1 2, provide guidance on how this is to be accomplished. The primary aims are to prevent ignition caused by an
13、 electrically energized component part and, in the event of ignition, to confine any resulting fire within the bounds of the enclosure of the electrotechnical product. Secondary aims include the minimization of any flame spread beyond the products enclosure and the minimization of harmful effects of
14、 fire effluents including heat, smoke and toxic or corrosive combustion products. Fires involving electrotechnical products can also be initiated from external non-electrical sources. Considerations of this nature are dealt with in the overall risk assessment. Fires are responsible for creating haza
15、rds to life and property as a result of the generation of heat (thermal hazard), the production of toxic and/or corrosive compounds, and the obscuration of vision due to smoke. Fire risk increases as the heat released increases, possibly leading to a flash-over fire. One of the most important measur
16、ements in fire testing is the measurement of heat release, and it is used as an important factor in the determination of fire hazard; it is also used as one of the parameters in fire safety engineering calculations. The measurement and use of heat release data, together with other fire test data, ca
17、n be used to reduce the likelihood of (or the effects of) fire, even in the event of foreseeable abnormal use, malfunction or failure of electrotechnical products. When a material is heated by some external source, fire effluent can be generated and can form a mixture with air which can ignite and i
18、nitiate a fire. Some of the heat released in the process is carried away by the fire effluent-air mixture, some is radiatively lost, and some is transferred back to the material, to generate further pyrolysis products, thus continuing the process. Heat may also be transferred to other nearby product
19、s, which may burn and then release additional heat and fire effluent. The rate at which thermal energy is released in a fire is defined as the heat release rate. Heat release rate is important because of its influence on flame spread and on the initiation of secondary fires. Other characteristics ar
20、e also important, such as ignitability, flame spread and the side-effects of the fire (see the IEC 60695 series). This technical specification, is based on the use of the cone calorimeter which is an instrument which measures heat release rate as well as other useful fire hazard parameters such as s
21、moke production, ignition time and mass loss. The need for heat release data from the combustion of insulating liquids is mentioned in IEC 60695-1-40 3. This technical specification provides a method for measuring the heat release from such materials and is also applicable to other combustible liqui
22、ds. Guidance on the use of the cone calorimeter is given in ISO 5660-3 4 and in IEC 60695-8-2 5. _ 1Figures in square brackets refer to the bibliography. DD IEC/TS 60695-8-3:2008 3 FIRE HAZARD TESTING Part 8-3: Heat release Heat release of insulating liquids used in electrotechnical products 1 Scope
23、 IEC 60695-8-3, which is a technical specification, specifies quantitative test methods for determining the heat release from the combustion of insulating liquids of electrotechnical products when exposed to a defined heat flux with spark ignition. Smoke production, ignition times and mass loss are
24、also measured. This technical specification may also be applicable to other liquid test specimens. This technical specification is intended for use by technical committees in the preparation of standards in accordance with the principles laid down in IEC Guide 104 and in ISO/IEC Guide 51. One of the
25、 responsibilities of a technical committee is, wherever applicable, to make use of basic safety publications in the preparation of its publications. The requirements, test methods or test conditions of this basic safety publication will not apply unless specifically referred to or included in the re
26、levant publications. HAZARD WARNING The testing of volatile liquids with this apparatus can lead to explosions so it is essential to examine all liquids using the preliminary testing procedure described in 8.1. 2 Normative references The following referenced documents are indispensable for the appli
27、cation of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60695-8-1, Fire hazard testing Part 8-1: Heat release General guidance ISO 5660-1:2002, Reaction-to-fire tests
28、Heat release, smoke production and mass loss rate Part 1: Heat release rate (cone calorimeter method) ISO 5660-2:2002, Reaction-to-fire tests Heat release, smoke production and mass loss rate Part 2: Smoke production rate (dynamic measurement) ISO/IEC Guide 51:1999, Safety aspects Guidelines for the
29、ir inclusion in standards IEC Guide 104:1997, The preparation of safety publications and the use of basic safety publications and group safety publications 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. DD IEC/TS 60695-8-3:2008 4 3.1 combustion
30、exothermic reaction of a substance with an oxidizer NOTE Combustion generally emits fire effluent accompanied by flames and/or visible light. ISO/IEC 13943, definition 23 7 3.2 critical ignition flux minimum heat flux, which is a multiple of 5 kWm-2and which with spark ignition causes a test specime
31、n to ignite in less than 1 200 s 3.3 extinction coefficient of smoke natural logarithm of the opacity of smoke divided by the path length of the light used to measure the smoke opacity IEC 60695-4, definition 3.18 6 3.4 fire general process of combustion characterized by the emission of heat and fir
32、e effluent accompanied by smoke, and/or flame, and/or glowing 3.5 fire controlled self-supporting combustion which has been deliberately arranged to provide useful effects and which is controlled in its extent in time and space NOTE In the English language the word “fire“ can have two meanings which
33、 translate into two different words in both French and German. ISO/IEC 13943, definition 40 7 3.6 fire uncontrolled self-supporting combustion which spreads uncontrolled in time and space ISO/IEC 13943, definition 41 7 3.7 fire effluent totality of gases and/or aerosols (including suspended particle
34、s) created by combustion or pyrolysis ISO/IEC 13943, definition 45 7 3.8 fire hazard physical object or condition with a potential for an undesirable consequence from fire 3.9 fire safety engineering application of engineering methods based on scientific principles to the development or assessment o
35、f designs in the built environment through the analysis of specific fire scenarios or through the quantification of risk for a group of fire scenarios DD IEC/TS 60695-8-3:2008 5 3.10 flame spread propagation of a flame front IEC 60695-4, definition 3.36 6 3.11 heat flux amount of thermal energy emit
36、ted, transmitted or received per unit area and unit time NOTE It is expressed in watts per square metre. 3.12 heat release thermal energy produced by combustion NOTE The typical units are joules. 3.13 heat release rate rate of thermal energy production generated by combustion NOTE The typical units
37、are watts. 3.14 ignition initiation of combustion NOTE The term “ignition” in French has a very different meaning (state of body combustion). ISO/IEC 13943, definition 96 7 3.15 mass loss rate mass of material lost per unit time under specified conditions NOTE It is expressed in kilograms per second
38、. ISO/IEC 13943, definition 119 7 3.16 opacity (of smoke) the ratio (I/T) of incident luminous flux (I) to transmitted luminous flux (T) through smoke, under specified test conditions IEC 60695-4, definition 3.67 6 3.17 oxygen consumption principle proportional relationship between the mass of oxyge
39、n consumed during combustion and the heat released NOTE A value of 13,1 kJg-1is commonly used. 3.18 pyrolysis chemical decomposition of a substance by the action of heat NOTE 1 The term is often used to refer to a stage of fire before flaming combustion has occurred. NOTE 2 In fire science no assump
40、tion is made about the presence or absence of oxygen. DD IEC/TS 60695-8-3:2008 6 3.19 quantitative fire test fire test which takes into account the circumstances of product use on which the test conditions are based or to which they can be related, and which measures a parameter or parameters, expre
41、ssed in well defined terms and using rational scientific units, can be used in the quantitative assessment of fire risk NOTE Such a test is sometimes referred to as a “performance-based fire test”. 3.20 smoke a visible suspension of solid and/or liquid particles in gases resulting from combustion or
42、 pyrolysis IEC 60695-4, definition 3.79 6 3.21 smoke production amount of smoke which is produced in a fire or fire test 3.22 smoke production rate amount of smoke produced per unit time in a fire or fire test NOTE 1 It is calculated as the product of the volumetric flow rate of smoke and the extinc
43、tion coefficient of the smoke at the point of measurement. NOTE 2 The typical units are m2s1. 4 General description of the test The test is performed to determine the heat release rate, total heat release, smoke production rate, total smoke production, time to ignition and mass loss rate of insulati
44、ng liquids used in electrotechnical products when exposed to specified heating conditions. For the purpose of the test, the test apparatus specified in ISO 5660-1 and ISO 5660-2 and additional equipment given in this standard shall be used. The liquid test specimen, contained in a test specimen tray
45、, is heated by a heat flux radiated from a conical electric heater set above the test specimen tray, and an electrical spark is applied as an ignition source. The heat release rate is measured using the oxygen consumption technique. The smoke production rate is measured by a laser beam system instal
46、led in the exhaust duct of the test apparatus. A load cell records mass measurements. 5 Test apparatus 5.1 Cone calorimeter The test apparatus specified in ISO 5660-1 and ISO 5660-2 shall be used with the exception of the test specimen tray which is replaced by the test specimen tray described in 5.
47、2. 5.2 Test specimen tray The test specimen tray shall have the shape of a square pan with an opening of 100 mm 1 mm 100 mm 1 mm at the top and an inside depth of 15 mm 1 mm. It shall be made of stainless steel plate with a thickness of 2,15 mm 0,25 mm. It shall include a handle to facilitate insert
48、ion and removal, and shall include a mechanism to ensure the central location DD IEC/TS 60695-8-3:2008 7 of the test specimen under the heater and proper alignment with the load cell. An example of the test specimen tray is shown in Figure 1. 25100 104 14 22 60 22 14 6022 86022 228 4017 IEC 548/08 D
49、imensions in millimetres Figure 1 Example of test specimen tray 5.3 Position of the test specimen tray The test specimen tray shall be located so that the surface of the liquid test specimen is 25 mm 1 mm below the lower edge of the conical heater. 6 Calibration The calibration shall be conducted in accordance with ISO 5660-1 and ISO 5660-2. The heat flux level shall be determined at a position in the centre of the surface of the liquid test specimen. The heat flux l
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