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ПІДТВЕРДЖУВАЛЬНЕ ПОВІДОМЛЕННЯ

Державне підприємство

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Наказ від 11.08.2016 № 236

EN 50399:2011

Commontestmethodsforcablesunderfireconditions-

Heatreleaseandsmokeproductionmeasuremcntoncablesduringflamespreadtest-
Testapparatus, procedures, results

прийнято як національний стандарт
методом «підтвердження» за позначенням

ДСТУ EN 50399:2016 (EN 50399:2011, ЮТ)

Загальні методи вогневих випробувань. Визначення показників тепловиділення
та димоутворення кабелів під час випробування на поширювання полум'я.

Випробувальне устатковання. Процедури випробування та оцінювання результатів

Копію цього стандарту можна отримати
у Національному фонді нормативних документів

З наданням чинності від 2016—09—01EUROPEAN STANDARD

EN 50399

NORME EUROPEENNE

E

April 2011

UROPAISCHE NORM

ICS 13.220 40; 29.060.20

English version

Common test methods for cables under fire conditions -
Heat release and smoke production measurement on cables during flame
spread test -
Test apparatus, procedures, results

Methodes d'essai communes aux cables soumis au feu -

Mesure de la chaleur et de la fumee degagees par les cables au cours de I'essai de propagation de la flamme - Appareillage d'essai, procedure et resultats

Allgemeine Prufverfahren fOr das

Verhalten von Kabeln und isolierten

Leitungen im Brandfall -

Messung der Warmefreisetzung und Raucherzeugung wahrend der PrQfung der Flammenausbreitung - Prufeinrichtung, PrQfverfahren und Prufergebnis

This European Standard was approved by CENELEC on 2011-02-28. CENELEC 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 application 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 Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom.

CENELEC

European Committee for Electrotechnical Standardization
Comite Europeen de Normalisation Electrotechnique
Europaisches Komitee fur Elektrotechnische Normung

Management Centre: Avenue Mamix 17, В -1000 Brussels

© 2011 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members

.Foreword

This European Standard was prepared by the Technical Committee CENELEC TC 20, Electric cables.

The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50399 on 2011-02-28.

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) 2012-02-28

• latest date by which the national standards conflicting

with the EN have to be withdrawn (dow) 2014-02-28Contents

Introduction 5

1. Scope 7

2. Normative references 7

3. Terms and definitions 7

4. Test apparatus 8

   1. General 8

   2. Air input 9

   3. Hood 9

   4. Exhaust duct 10

   5. Instrumentation in the exhaust duct 10

   6. Extracting ventilator 11

   7. Smoke production measuring equipment 11

   8. Combustion gas analysis equipment 12

5. Qualification of test apparatus 12

   1. General 12

   2. Flow distribution measurements 12

   3. Sampling delay time measurement 13

   4. Commissioning calibrations 13

   5. Routine calibration 13

6. Test procedure 14

   1. Initial test conditions 14

   2. Test sample 14

   3. Sample conditioning 14

   4. Determination of the number of test pieces 15

   5. Mounting of the test sample 16

   6. Exhaust volume flow 17

   7. Ignition source 17

   8. Flame application time 17

   9. Testing operations 18

   10. Observations and measurements during the test 18

7. Determination of parameters derived from the test 19

   1. Calculation of HRR and SPR parameters 19

   2. Determination of extent of flame spread {FS} 19

8. Test report 20

1. General 20

2. Contents 20

3. (normative) Calculation of heat release 31

A.1 Volume flow 31

A.2 Generated heat effect 31

A.3 Calculation of the mole fraction of water vapour in the air 33

4. (normative) Smoke production 34

5. (informative) Additional information on Reynolds number in Figure 5 35

6. (normative) Flow distribution inside the duct 36

D.1 General 36

D.2 Velocity profile factor k_c 36

Annex Є (normative) Commissioning calibrations 39

E.1 General procedures for separate pieces of equipment 39

E.2 Gas analyser calibrations 39

E.3 HRR calibrations 40

E.4 Smoke measurement system calibration 44

Annex F (informative) Guidance for calibration procedures for specific measuring equipment 47

F.1 General procedures for separate pieces of equipment 47

F.2 Gas analyser calibrations 47

F.3 Check of propane mass flow controller or rotameter 47

F.4 Optical filter check for white light systems 48

Annex G (normative) Calculation of HRR_av, SPR_arand FJGRA 49

G. 1 Calculation of HRR_m 49

G.2 Calculation of SPR_m 50

G.3 Calculation of the Fire Growth Rate Index (FIG RA) 50

8. (informative) Guidance on the choice of test equipment 51

9. (informative) Guidance on the file format for data from the test 52

Bibliography 56

Figures

1. - General arrangement of test apparatus 22

2. - Schematic of a hood 23

3. - Typical guide vanes 24

4. - Bidirectional probe 25

5. - Probe response versus Reynolds number 26

6. - Sampling probe 27

7. - Schematic diagram of sampling line 28

8. - Optical system - General arrangement 29

9. - Mounting arrangement for Class B1ca 30

4. 1 - Section of the exhaust duct - Positions for measurement of the gas velocity 37

5. 1 - Overview of commissioning calibrations 46

Tables

Table 1 - Mounting as a function of cable diameter 17

Table E.1 - Burner ignition times and HRR levels 41

Table E.2 - Example of determination of commissioning к, factor 43

Table 1.1 - Example of the recommended raw data file format 53

Introduction

EN 50399 specifies the test apparatus and test procedures for the assessment of the reaction to fire performance of cables to enable classification under the Construction Products Directive [1] to be achieved.

The test method describes an intermediate scale fire test of multiple cables mounted on a vertical cable ladder and is carried out with a specified ignition source to evaluate the burning behaviour of such cables and enable a direct declaration of performance. The test provides data for the early stages of a cable fire from ignition of cables. It addresses the hazard of propagation of flames along the cable, the potential, by the measurement of the heat release rate, for the fire to affect areas adjacent to the compartment of origin, and the hazard, by the measurement of production of light obstructing smoke, of reduced visibility in the room of origin and surrounding enclosures.

The following parameters may be determined under defined conditions during the test:

1. flame spread;

2. heat release rate;

3. total heat release;

4. smoke production rate;

5. total smoke production;

6. fire growth rate index;

7. occurrence of flaming droplets/particles .

The apparatus is based upon that of EN 60332-3-10 but with additional instrumentation to measure heat release and smoke production during the test. It has been demonstrated [3] that the utilisation of these additional measurement techniques, proven for other standard tests, e.g. for building products, are appropriate for assessing the reaction to fire performance of electric cables. These techniques include heat release and smoke production measurements. Compared with existing test methods described in EN 60332-3-10, they enable a more comprehensive assessment system, which is both more precise and sensitive, and enables a wider range of fire performance levels.

Care should be exercised in relating the parameters measured to different safety levels in actual cable installations as the actual installed configuration of the cables may be a major determinant in the level of flame spread, heat release and smoke production occurring in an actual fire. These parameters depend upon a number of features, such as

1. the volume of combustible material exposed to the fire and to any flaming or heat which may be produced by the combustion of the cables;

2. the geometrical configuration of the cables and their relationship to an enclosure;

3. the temperature at which it is possible to ignite the gases emitted from the cables;

4. the quantity of combustible gas released from the cables for a given temperature rise;

5. the volume of air passing through the cable installation;

6. the construction of the cable, e.g. armoured or unarmoured, multi or single core.

All of the foregoing assumes that the cables are able to be ignited when involved in an external fire.

The conditions of cable mounting, including volume of material exposed and geometrical configuration of the cables on the test ladder, and volume of airflow through the chamber have been chosen to be in accordance with that required by the Commission Decision 2006/751/EC [2]. CENELEC has not been involved in the definition of these parameters. These standardised conditions provide the basis for classification but do not necessarily correspond to conditions found in a particular cable installation.

NOTE Further information on the use of standardised conditions for classification with respect to product end-use application may be found in European Commission Guidance Paper G [4].

1. EN 50399 gives details of the apparatus to be used in conjunction with the equipment described in EN 60332-3-10 in order to carry out the measurement of heat release and smoke production during the test. Details of the test procedures are also given.Scope

EN 50399 specifies the apparatus and methods of test for the assessment of vertical flame spread, heat release, smoke production and occurrence of flaming droplets/particles of vertically-mounted bunched wires or cables, electrical or optical, under defined conditions.

NOTE For the purpose of this standard the term "electric wire or cable" covers all insulated metallic conductor cables used for the conveyance of energy or signals.

EN 50399 details the apparatus and the arrangement and calibration of the instrumentation to be installed in order to measure the heat release and the smoke production during the test. The combustion gases are collected in a hood above the test chamber and conveyed through an exhaust system, which allows the measurement of heat release rate and smoke production. Test procedures to be used for type approval testing for classification of cables in Euroclasses B1_ca, 62^, Cea and Dea are given. Cable installation on the test ladder and the volume of air passing through the chamber are in accordance with the Commission Decision 2006/751/EC [2] which is reflected in the requirements of this standard.

The apparatus described in this standard shall be used in conjunction with that described in EN 60332-3-10.

2. Normative references

The following referenced documents are indispensable for the application 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.

EN 60332-3-10, Tests on electric and optical fibre cables under fire conditions - Part3-10: Test for vertical flame spread of vertically-mounted bunched wires or cables- Apparatus (IEC 60332-3-10)

EN 60584-1, Thermocouples - Part 1: Reference tables (IEC 60584-1)

EN ISO 13943:2010, -Fire safety- Vocabulary (ISO 13943:2008)

ISO 3966, Measurement of fluid flow in closed conduits - Velocity area method using Pitot static tubes

3. Terms and definitions

For the purpose of this document, the terms and definitions given in EN ISO 13943:2010 and the following apply.

heat release rate

HRR

thermal energy released per unit time by an item during combustion under specified conditions

total heat release

TUR

integrated value of the heat release rate over a defined period

smoke production rate

SPR

total smoke production

TSP

integrated value of the smoke production rate over a defined period

flame spread

FS

propagation of a flame front

NOTE In this standard the extent of flame spread is determined as the extent of damage measured by the onset of char.

fire growth rate index

FIGRA

highest value of the quotient between HRR and time

NOTE 1 In this standard FIGRA is expressed in W/s.

NOTE 2 Details of the calculation of FIGRA are given in Annex G.

flaming droplets/particles

material separating from the specimen during the test and continuing to flame for a minimum period as described in this test method

E-value

heat release per volume of oxygen consumed

4. Test apparatus

   1. General

The test apparatus shall consist of the test chamber, standard ladder and ignition source, as described in EN 60332-3-10, with the additional features as specified in 4.2 to 4.8. Figure 1 shows a schematic diagram of the apparatus. The ignition source shall be one ribbon-type propane gas burner. The ladder shall be the standard ladder of (500 ± 5) mm width. The air supply shall be a system that blows air into the chamber at an airflow rate of (8 000 ± 400) l/min.

The additional features of the apparatus shall be capable of measuring the following parameters:

1. oxygen consumption;

2. CO₂ production;

3. volume flow in the exhaust duct;

4. smoke production.

WARNING Care should be taken in monitoring and extinguishing cable fires once the test specimen has started to propagate fire. Some specimens may have a very high capacity to generate high heat release levels that could damage the test equipment and instrumentation. It is important that testing staff are sufficiently trained in dealing with such fires and have adequate fire fighting facilities at their disposal during testing.

NOTE 1 It is recommended that indicative temperature measurements are taken through the use of thermocouples installed along the cable bunch being tested at 1,5 m and 2,5 m above the burner and at the top of the chamber or in the duct. Such measurements can give an early indication of any excessive temperature or burning condition that may require the test to be aborted in order to prevent damage to the test equipment

All data shall be measured and recorded every 3 s. These point measurements shall be averaged over a period of 30 s for parameters relating to heat release and 60 s for parameters relating to smoke production, in order to provide the required data. The data shall be processed according to the requirements of this standard.

NOTE 2 It is necessary to produce the average measurement in order to damp the variability caused by frequent point measurement.

The additional features and their associated measurements shall allow for calculation of the following:

1. heat release (see Annex A);

1. heat release rate (HRR);

2. total heat release (THR)',

3. fire growth rate index (F1GRA);

2. smoke production (see Annex B);

1. smoke production rate (SPR);

2. total smoke production (TSP).

Air shall be introduced to the test chamber through a plenum box fitted directly underneath, and of approximately the same dimensions as, the air inlet aperture. The depth of the plenum box shall be (150 ± 10) mm. Air shall be blown into the plenum box from a fan through a rectangular straight section of duct of constant cross section of (300 ± 10) mm width and (80 + 5) mm height and a minimum length of 800 mm, which shall enter from the rear of the chamber and be parallel to the floor and along the burner centre line as shown in Figure 1. The duct shall be arranged to inlet air to the plenum box through an aperture in the longest side, centred horizontally and such that the bottom of the duct shall be no greater than 10 mm above the bottom of the plenum box. A grid shall be fitted in the air inlet aperture to achieve uniform flow of the air. The grid shall be constructed of steel plate approximately 2 mm thick with holes of approximately 5 mm diameter drilled at approximately 8 mm spacing between centres.

The airflow rate shall be measured in a circular duct prior to the rectangular cross section duct. It shall be measured by a gas flow measuring device located at a straight section of the circular duct. The minimum length of straight circular section before and after the measuring device shall be selected according to the technical specification of the measuring device.

NOTE 1 A fluid flow measuring system according to either EN ISO 5167-2 (orifice plate) or EN ISO 5167-4 (Venturi tube) is recommended. Alternatively, a Pitot tube taking multiple samples across the section of the duct and averaging to account for variations across the section or a hot wire anemometer measuring at multiple positions across the section of the duct as described in Annex D may be used.

The airflow shall be set prior to a test at (8 000 ± 400) I / min and shall not be changed during the test. The airflow shall be checked throughout the test and shall not vary by more than 10 % of the set value.

NOTE 2 This information does not need to be recorded.

A hood (see Figure 2) having a truncated shape, and where the base has a minimum length of 1,50 m and a minimum width of 1,00 m, shall be centred above the outlet of the test chamber. The base of the hood shall be raised above the top of the test chamber, with the largest side of the hood parallel to the largest side of the outlet of the chamber.

NOTE 1 A gap of approximately 200 mm to 400 mm between the top of the test chamber and the base of the hood has generally been found suitable.There shall be a chamber above the hood to allow a connection to the exhaust duct.

NOTE 2 Plates/baffles may be installed in the hood to improve mixing of the air I effluents.

The system shall be designed to collect all the combustion products leaving the test chamber through the outlet during the test. There shall be no leakage of flames or smoke. The exhaust capacity shall be at least 1 m³/s at normal pressure and a temperature of 25 °С. The exhaust system design shall not be based on natural convection.

NOTE 3 In order to extract all gases and vapours, especially in the case of heavily burning cables, or cables which require to be specially extinguished and produce high volumes of gases and vapours, an exhaust system with a capacity of 1,5 m³/s is recommended.

An exhaust duct shall be connected to the hood as described in 4.3. The inner diameter, D, of the duct shall be in the range 250 mm to 400 mm. The straight section of the duct shall have a minimum length of 12 x D, such that a uniform flow profile is established at the point of measurement.

NOTE A uniform flow profile can be obtained by introducing guide vanes (see Figure 3) before and after the measuring section such as described in EN 14390. This is highly recommended in order to obtain as precise measurements as possible.