Common test methods for cables under fire conditions digital · 20.5kW propane burners as speciﬁed in the IEC 603323 standard. EN 50399 Common test methods for cables under ﬁre

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Common test methodsfor cables under fireconditions(EN 50399; IEC 603323)

Common test methods for cables under fire conditions_digital 15/07/2020 11:30 Page 1

FIRE TESTING TECHNOLOGY

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Construction ProductRegulationsTraditionally electric cables havenot been included or classified innational building regulations . Theinclusion of electric cables withinthe Construction ProductsRegulations (CPR) changes thissituation. Cables are to be testedusing 5 test methods, and classifiedby the provisions of EN 135016which is a parallel standard in theexisting CPR classification standardEN 135011. EN 135016 coverselectric cable requirements anddefines all the test methods and

performance criteria that must bemet in order for a cable to meet aparticular fire classification (Aca,B1ca, B2ca, Cca, Dca and Eca).

According to EN 13501 Part 6:“Classification using data fromreaction to fire tests on electriccables”, cables are tested using 5 test methods in which theEN 50399 is the major test protocolfor Classes B1ca, B2ca, Cca and Dca.This test protocol was developed bySP (Sweden), ISSeP (Belgium), CESI(Italy) and Interscience (UK) withthe help of FTT fire scientists, in anEU funded project called FIPEC, FirePerformance of Electric Cables. TheFIPEC project included a study ofcable installations and relevantreference scenarios as well as acomprehensive test program ofdifferent families of cables. This,together with subsequent industrytest programmes, was used in thedevelopment of the proposal forthe European testing andclassification system. Theclassification utilises the resultsobtained from IEC 603323 testequipment fitted with heat andsmoke release measurementinstrumentation.

IEC 60332 Series Testson electric and opticalfibre cables under fireconditions Parts 1 and 2 of IEC 60332 specifymethods of test for flame spreadcharacteristics for a single verticalinsulated wire or cable. IEC 60332Part 3 specifies methods of test forthe assessment of vertical flamespread of vertically mounted wiresor cables, electrical or optical.

Heat release and smokeproduction measurementon cables during flamespread test. (Test apparatusalso meets IEC 603323series tests specification)

IEC 603323Schematic


COMMON TEST METHODS FOR CABLES UNDER FIRE CONDITIONS

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situated 150mm from the front wallof the test chamber.

The standard requires the air flowrate to be 5000 l/min, measured atthe inlet before the testcommences. This parameter can beregulated during the test.

An outlet of 300mm × 1000mm isat the rear edge of the top of thetest chamber. The back and sides of

FTT IEC 603323 SeriesTest ApparatusThe test rig comprises of a verticaltest chamber of 1000mm (W) ×2000mm (D) × 4000mm (H); thefloor of the chamber is raisedabove ground level. The testchamber is nominally airtight alongits sides, air being supplied at thebase of the test chamber throughan aperture of 800mm × 400mm

Gas mass flow control, ignition and flame detection system mounted on the Gas Diverterplate (cover not shown)

Gas control box mounted on wall

the test chamber are thermallyinsulated to give a coefficient ofheat transfer of approximately0.7W/(m2∙K). The distance betweenthe ladder and the rear wall of thechamber is 150mm and betweenthe bottom rung of the ladder andthe ground 400mm. Cables can bemounted on two types of ladder; astandard ladder of 500mm widthand a wide ladder of 800mm width.

Side view of cable test chamber, hood and ducting Front view of cable test chamberand hood



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This apparatus also consists of allinlet air and exhaust ducting, gassupply and control system, and two20.5kW propane burners as specifiedin the IEC 603323 standard.

EN 50399 Common testmethods for cablesunder fire conditions –Heat release and smokeproductionmeasurement on cablesduring flame spread testIEC 603323 apparatus can bemodified to measure heat releaseand smoke production by fitting asmall instrumented section ofducting into the exhaust system ofthe rig and using this withassociated FTT gas analysisinstrumentation and software andusing a modified test protocol.

The standard specifies the cablemounting methods and both the airinlet duct design and air flow ratesinto the chamber. The combustiongases are collected in a hood above

the test chamber and conveyedthrough an exhaust system whichcontains a duct section housing thesampling probes, thermocouples,mass flow probes and smokemeasuring system. Test results arecalculated from data on continuousmeasurement of the oxygenconsumed and carbon dioxidegenerated in the combustionprocess using FTT’s data acquisitionand analysis software.

The Heat Release and SmokeProduction MeasurementApparatus includes:

1. Probe and Sensor Duct SectionA stainless steel duct section ofapproximate dimensions 0.4mdiameter by 0.762m long fitted toan exhaust system. The duct willcontain ports for: • Sampling tube for flue gas

extraction (for gas analysis)• Smoke obscuration system• Mass flow monitoring• Thermocouple for measuring

exhaust gas temperature

DIN 50055 white light system

Duct section for EN 50399

19" Gas Analysis Rack



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By connecting this duct section tothe gas analysis rack the client isable to make measurements on theeffluent from the rig to determineoxygen consumption and carbondioxide production in the exhaustduct to calculate heat release and smoke density in the exhaustduct with either the DIN 50055white light system or laser smoke system.

2. Gas Analysis Instrumentation Heat release measurement isobtained by sampling combustionproducts from the exhaust andcomputing heat release rates fromthe volume flow rates and themeasured oxygen consumption andcarbon dioxide generation in theThe FTT Calorimeter Analyser ishoused in a 19" rack that can beplaced in the laboratory.

The FTT Calorimeter Analysercontains:• FTT Calorimeter Analyser

featuring Paramagnetic oxygensensor with atmosphericpressure compensation andInfrared carbon dioxide sensor(010%). Carbon monoxide (01%) is optional.

• Developed and optimisedspecifically for the FTTcalorimeters this analyserfeatures flow control and bypassfor fast response, low drift andnoise and is compatible withsmall, medium and largecalorimeters.

Flue gas conditioning traincomprising:• Soot filtration• Refrigerant cold trap• Drying columns • Pump and waste regulators

Instrumentation for volume flowmeasurement:• Bidirectional probe• Differential pressure transducer

Clients already owning the FTT DualCone Calorimeter, ISO 9705 RoomCorner Test or EN 13823 SBI Testcan use their gas analysisinstrumentation to measure heatrelease rate of the EN 50399 test.Alternatively the EN 50399 gasanalysis instrumentation can beused with other FTT calorimeters(e.g. Dual Cone Calorimeter,ISO 9705, SBI, etc.).

3. Smoke Measurement Systems FTT offers two smoke measurementsystem options, laser or white lightsystems. The laser system is similarto that used in the Cone

Calorimeter and complies withthat specified in ISO 5660. Thewhite light system is similar tothat used in the SBI test andconstructed to DIN 50055.

• Density Photometric SystemDIN 50055A photometric systemconsisting of a white lightsource and lens, a siliconphotodiode detector, alongwith housings and controls.

The photodiode detectorconsists of an achromaticsystem of lenses, a siliconphotoelectric cell and a highgain lownoise amplifier. Thelatter is capable of measuringrelative light intensity againsttime as percentage

Test chamber interior detail with propane burner



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CableSoft SoftwareThe FTT EN 50399 test apparatususes sophisticated instrumentationand we supply the CableSoftsoftware package to make thecalibration and use of theinstrument as easy as possible.

CableSoft is a powerful, yet easy touse, Microsoft Windows basedapplication that allows the user toperform most operations requiredon the apparatus with a computer.It is based on push buttons andWindows data entry boxes andselectors and capable of:• Showing the status of the

instrument• Calibrating the instrument and

storage of calibration results• Collecting data generated during

a test• Calculating the required

parameters• Presenting the results required

by the Standards

All the functions available inCableSoft can be accessed from theMain Menu which offers 7 options:

transmission continuously overthe ranges to be studied. Thesystem has a linear responsewith respect to transmission andan accuracy of better than±1.5% of the maximum reading.The photodiode is housed in anassembly with a collimating lens,in a tube mounting on the sideof the exhaust duct.

• Laser Smoke SystemAs an alternative to theDIN 50055 system, a laser smokesystem can be used. It features a 0.5mW HeliumNeon laser smoke and supportsystem, power supplies,calibration and zeroing device forsmoke extinction coefficient. Thedetector output is designed witha Main and CompensatingDetector to eliminate drift and issupplied with 0.3 and 0.8 neutraldensity filters for calibrating theunit. Calibration and calculationof the associated smokeobscuration parameters can beperformed by FTT software.

4. Data Acquisition and AnalysisSoftwareThe signals are collected using aData Acquisition Unit. A Windowsbased software package enablesdata acquisition and analysis todetermine the various parametersneeded for heat releasedetermination.

5. Burner Gas Control UnitThe system supplied comprises of agas flow control and ignition systemfor the burner. A spark igniter isprovided and a typeKthermocouple monitors thepresence of a flame. Two mass flowcontrollers (MFCs) control thepropane gas and air flow and aVenturi air gas mixer.

Each MFC is housed on the ‘GasDiverter’ plate fitted on the outsidewall of the test chamber. This isnormally protected behind a cover.

The Gas Control Box enables eachgas to have 3 preset levels. Afterpresetting, the burner output canbe switched between these levels.It also houses the numerous power supply units for the MFCsand solenoid valves, the ignitionsystem and controls for the safety features.

The signals from the MFCs aredisplayed on screen using FTTCableSoft software, which showsthe mass flow rate of the respectivegas and the corresponding heatoutput and facilitates any requiredadjustment. The mass flow rate ofeach gas is also stored by thesoftware enabling heat releasefrom the burner to be subtractedfrom the total measured heatrelease rate (of specimen andburner) so that the heat releaserate from the specimen alone canbe determined.

Main menu of CableSoft



• ToolsThis gives access to the useful toolsof Oxygen analyser drift calculator,Smoke system drift calculator,Commissioning kt calculator andGas flow calculator.

• Print ReportThe results from a cable test, a daily check test or the threecommissioning tests can be viewedand reports printed.

• ConfigureThis allows settings for the softwareand system to be viewed andmodified.

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• Start TestThis allows quick and easy setup ofa test with the cable and ignitionburner or a set of dummy testswhich should be conducted everyday to check the system is workingcorrectly.

• StatusThis displays the signals from all thetransducers and shows the exhaustvolume flow rate, inlet air volumeflow rate, the heat release ratefrom the burner, the mean ducttemperature and the extinctioncoefficient.

• CalibrationsThis allows the user to calibrate thetransducers in the system. Theseare oxygen, carbon dioxide and (iffitted) carbon monoxide cells,

differential pressure transducer,smoke system (white light or laser)and the gas and air mass flowmeters (if fitted). Each transducershould be calibrated to ensure thevalidity of the test results.

• CommissioningA set of three commissioningroutines are performed todetermine the kt constant used inthe calculation of the exhaustvolume flow rate before using thetest apparatus and after any majorchanges. These three sets ofcommissioning routines aredetermining the flow profile,conducting propane burns at threedifferent heat release levels, and amethanol pool burn. Thecommissioning results can also beviewed and reports printed.



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Technical SpecificationIEC 603323/EN 50399 Burning Behaviour of Bunched Cable Test

Burners

Burner Two 10" ribbon burners• 20.5 kW• Spark ignition• Thermocouple and solenoid valve interlock system for gas safety

Propane Supply System PLC gas control system

Venturi mixer

Mass flow controllers• Burner 1: 0.061.2 g/sec for propane• Burner 2: 0.0350.7 g/sec for propane• Air: 0.214.2 g/sec for air

Enclosure and Air Supply

Enclosure Vertical test chamber 1000 mm W × 2000 mm D × 4000 mm H; the floor of the chamber israised above ground level.

Nominally airtight along its sides, air being admitted at the base of the test chamberthrough an aperture of 800 mm × 400 mm situated 150 mm from the front wall of the testchamber.

Air Supply Single inlet centrifugal fan • 480 m3/hr• Altivar 30 W inverter

Ladder Types There are two types of ladder; a standard ladder of 500 mm width and a wide ladder of800 mm width

Ladder Lifting Electric winch (Max 500 kg)Pulley system

Control Unit

Control Unit Solid state gas control system with PLC control5V PSU4 process control meters to display process parameters2 Type K temperature controllers for interlock and safety



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Heat Release and Smoke Measurement (For EN 50399 only)

FTT Calorimeter Analyser Gas analyser • Paramagnetic oxygen sensor with flow control and bypass for fast response and

pressure compensation• Infrared carbon dioxide (010%) sensor with flow control and bypass for fast

response• Can also be supplied with infrared carbon monoxide (01%) sensor with flow control

and bypass for fast response

Gas Sampling Double ended sample pump (diaphragm) • Max flow: 33.0 l/min • Pressure: 2.5 bar

Soot filter • Primary: 93% efficiency at 0.01 µm• Secondary: 100% efficiency at 0.3µm

Water removal• Chiller unit• Drying columns with desiccant

Pressure controller relief valve• Relief pressure 0.070.7 bar

Probe and Sensor Duct Section Stainless steel duct section of approximate dimensions 0.4 m diameter by 0.762 m lengthcontaining ports for:

1. Sampling tube for flue gas extraction (for gas analysis)2. Smoke obscuration system3. Volume flow monitoring4. Thermocouple for measuring exhaust gas temperature5. Thermocouple for measuring gas temperature at smoke measuring position

By connecting this duct section to an FTT gas analysis rack the user is able to makemeasurements on the effluent from the rig to determine oxygen consumption and carbondioxide production for calculating heat release and smoke density in the exhaust duct.

Data Acquisition Signals are collected using a Keysight data acquisition/switch unit• 3slot cardcage • Scan rates up to 250 channels/s are available with a 115 kbaud RS232 and PCI GPIB

interface as standard



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Heat Release and Smoke Measurement (For EN 50399 only)

Smoke Density Photometric Light sourceSystem DIN 50055 • Gas filled tungsten filament lamp

• Power provided and regulated by a triple output power supply with accuracy ±5% • Housed with an appropriate collimating lens to ensure parallel light projection across

the duct, in one of the tube mounting sites on the side of the exhaust ductPhotodetector

• Achromatic system of lenses • Silicon photoelectric cell and a highgain lownoise amplifier, which is capable of

continuously measuring relative light intensity against time as percentagetransmission over the ranges to be studied

• Linear response with respect to transmission and an accuracy of better than ±1.5%of the maximum reading

• Housed in an assembly with a collimating lens, in one of the tube mounting sites onthe side of the exhaust duct

• Power provided by a regulated triple output power supply with accuracy ±5%• Active area: 3.6 × 3.6 mm • Spectral response rate: 320 – 1100 nm

Calibrated filters• 0.04 Neutral Density • 0.10 Neutral Density • 0.30 Neutral Density • 0.50 Neutral Density • 0.80 Neutral Density • 2.00 Neutral Density

Laser Smoke Measurement Light source(Option) • 0.5 mW He Ne laser

• 632.8 nmPhotodetector

• Silicon photodiodes Calibrated filters

• 0.30 Neutral Density • 0.80 Neutral Density

SEVICES REQUIRED

Extraction Connected to the FTT electric cable fire test rigContinuous extraction of a volume flow of 0.50m3/sec to 2m3/sec

Electrical Power 230VAC 50/60 Hz 10A at the control panel

Air Supply Pressure regulated clean, oilfree shop air at a maximum flow rate of 200 l/minAlternatively, a small compressor situated on the roof

Gas Supply Commercial propane 95% minimum purity at a pressure between 34 bar

Due to FTT’s continuous development policy, technical changes could be made without prior notice.



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Unrivalled Experience inDesign and ManufacturingFTT’s site in East Grinstead, is home to the largest group of fire scientists andinstrumentation design engineers working on fire testing instrumentation, and is at the heart of our design andmanufacturing. For more than 30 years FTT has provided the highest quality instruments and service for fire testing and research professionals worldwide, directly and through its extensive global sales and support network.

Quality• Worldclass

manufacturing inaccordance withmultiple internationaland national standards,including: EN, ISO &ASTM

• ISO 9001, ISO 14001certified

Integrity• A dedicated team

passionate about firetestinginstrumentation andcontinuous productimprovement

• Delivering reliable,robust and easytouseinstruments for thepast 30 years

Excellence• A worldclass team

made up of qualifiedfire scientists,mechanical, electricaland electronic fireinstrument designengineers andproduction, installationand maintenanceengineers

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• Leading global supplierof the ConeCalorimeter, LargeScale Calorimeter, NBSSmoke Chamber andOxygen Index


Documents

Common test methods for cables under fire conditions digital · 20.5kW propane burners as speciﬁed in the IEC 603323 standard. EN 50399 Common test methods for cables under ﬁre